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CB350 — Rebuild and Functional Restoration

CrazyChucky

CrazyChucky

Well-known Member
Joined
Jun 19, 2024
Total Posts
64
Total likes
65
Location
Baltimore MD
Hi all! I've got all the old gas cleaned out of my CB350 and it starts and runs, but before I worry about tuning it all up, I wanna go ahead and fix the kickstarter — which matches the description in this thread — since I'll have to open up the lower crank case.

I'm pretty mechanically inclined, have done a good bit of reading and video-watching, and used to regularly ride and (somewhat inconsistently) maintain this very bike, so I've comfortably gotten as far as removing everything in the way: exhaust pipes / studs, brake pedal, drive sprocket, carbs, foot peg bracket, starter motor, and even the ignition switch and horn just to give myself as much room as possible.

Now I'm at the point of the actual removal itself. Both the Honda and Clymer manual are pretty glib about just pulling it out on the right side. I've seen suggestions online of using a hoist, or if the frame is bare, putting the engine on its side and sliding the frame down over it. Is that viable with the tires and forks and all attached? What's the best way to do it myself, and/or would I really be better off requisitioning a friend?
 
It will be too heavy and clumsy to lift the rolling chassis off the engine, but the frame-over method is great when you're putting a bike back together that has been completely apart. Most just grab the lump and lift, tilt and tip as necessary to get the engine out of the frame. Those who have done far more 350s will be along to give you some finer points like how far forward or backward to tip it, etc, but that's basically it once you have everything removed and pout of the way. Also, some remove the starter motor to make more room at the front as well. The small sprocket will come off the shaft inside the left crankcase cover, but you'll be pulling all that apart later anyway.
 
Take out the oil drain plug and drain the oil. Leave the plug out. I stuff a bit of cloth in the hole after it's drained.

If you are going to be doing a total tear down then pull the right side cover off and take off the oil sludge trap, oil pump and clutch basket. On the left side pull the covers and take off the rotor. You can use the rear axle as a remover for the rotor if you don't have the proper one. You also need a special socket to remove the sludge trap nut.

Place a small jack under the engine ... helps to have a helper move it up or down in small increments. Have a platform to place the engine on the right hand side just lower than the frame rail.

Place some towels on the backbone of the frame, straddle the frame with your chest on the towels .... lift, tilt, do the hokey pokey, move the engine to the right and out. Sorry can't give much better instructions than that even after pulling several of these lumps. The jack can be used to lift initially but will need to be dropped as the removal progresses.

If at all possible I do the frame over the engine especially if fresh paint on the frame is involved.
 
Thank you both, that's good info! I already drained the oil but it didn't occur to me that leaving the plug off removes a point of interference and gives it a flatter bottom to rest on. The starter motor's already off.

I've already got the rotor off (I have a rotor puller), but I'll go ahead and get the oil trap and clutch too. I have the fancy socket.

I don't have a jack, but I do have a wood / metal shop at my disposal so whipping up the target platform at the right height should be simple.
 
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I built a platform out of quart paint cans and a sheet of plywood. Because I was really nervous about having the engine just tip over and crash on the garage floor I screwed a hefty hook into a ceiling beam and connected a tie-down from the hook to the top of the engine. I let it have some slack so I could maneuver the engine, but the tie down was short enough to stop the engine from falling hard on the concrete. When the engine was on the platform I tightened the tie-down so it would stay upright while I cleaned the frame and did the work to have it be ready for reassembly, then moved the frame out of the way so I could work on the engine.
 
Interesting, that's not a bad idea. I'm working in a basement so I've got plenty solid floor joists above me. I should be able to get it out of there today.

One more question. The impetus for this is the kickstarter, and for that I only need to open up the bottom end. The bike also only has about 11,000 miles on it (7,000 from me), and I haven't noticed any particular top-end issues.

That said, it's never been rebuilt, I'll have it out of the frame anyway, and I do already have a full set of new gaskets. Do you think it'd be worth rebuilding the top end too while I'm at it, just to get fresh seals and double check what's going on in there?
 
I have never seen a 350 engine that hadn't been opened up not require the timing chain rollers regardless of mileage.

For my rebuilds I always replace the timing chain, rollers, guides and the 2 piece pivot that the arm of the rollers is attached to.
 
CrazyChucky said:
Interesting, that's not a bad idea. I'm working in a basement so I've got plenty solid floor joists above me. I should be able to get it out of there today.

One more question. The impetus for this is the kickstarter, and for that I only need to open up the bottom end. The bike also only has about 11,000 miles on it (7,000 from me), and I haven't noticed any particular top-end issues.

That said, it's never been rebuilt, I'll have it out of the frame anyway, and I do already have a full set of new gaskets. Do you think it'd be worth rebuilding the top end too while I'm at it, just to get fresh seals and double check what's going on in there?
Click to expand...
In for a penny, in for a pound. Once you open it expect to start spending money to correct all the big and little faults you will find.
 
SUCCESS!

IMG_1140.png

Wasn't anywhere near as difficult as I'd imagined, really. (I put the right cover back on after removing the clutch basket and oil trap. I found it easier to grab and maneuver that way.)

Further disassembly will wait for another day. For the most part everything so far looks good; the oil trap barely even needs cleaning. It was completely missing its circlip though! It's been long enough that I honestly don't remember if it was there before. The cap was still safely in its spot, at least.

IMG_1120.png
Oh goodie!


IMG_1119.png
Found some little bits of plastic and... curved slivers of aluminum? The edge of a crank case hole somewhere maybe? Dunno if that's anything to be concerned about.
 
The black bits of plastic will probably be from the hard rubber rollers in the timing chain assy.
So well worth splitting the top end off ( once the cases are also split) and inspecting.
the silver looking curved item looks to me like one of the large bearing outer ring retaining clips.
These are Steel from memory so test with a magnet to find out.
if it is from where I suspect then splitting the case for the kick start fix will show them.
There are two of them in the gear box area, on the main and lay gearbox shafts:
item #1 here
www.cmsnl.com

Honda CB350 GENERAL EXPORT E-12 TRANSMISSION - buy E-12 TRANSMISSION spares online

✓access the E-12 TRANSMISSION schematic✓find Honda E-12 TRANSMISSION spares easily✓E-12 TRANSMISSION parts quickly delivered
www.cmsnl.com www.cmsnl.com

cheers
 
Got the top end all torn down today, and plan to split the crankcase tomorrow. (I should take out the long cylinder head studs, right? I don't see a good way to set the thing upside down without doing so.)

Gary, since I haven't gotten into the lower end yet I can't report on the state of those retaining clips, but these fragments are definitely nonmagnetic and look/feel like aluminum. The rubber roller I can see is *definitely* chewed up, good call.

IMG_1156.jpeg

So uh...... is this a concerning amount of carbon buildup? Seems like a lot, but I have no basis for comparison.
 
Personally, I don't like disturbing cylinder studs that have been in place for 50 years so I leave them alone. We all turn our engines upside down on the studs for reassembly (and disassembly too), or you can use a milk crate and slip the studs through the bottom. Or some have fashioned a wooden stand with the studs sticking down through it. The studs, and their threads, are pretty tough.

As to the carbon amount, it looks a bit heavy and dark, maybe was running rich for a while? Doesn't look too oily.
 
My mantra is don't remove the studs and definitely don't remove the windage tray in the bottom case half unless it it broken. I have never had any issues cleaning the lower case with the tray in place.

Also for the kick starter buy a new circlip and put it in correctly.

And get a circlip for the oil slinger, new o-rings for everything including the rocker spindles.

I would also suggest doing the mods to improve the oil flow at higher rpms.
 
Duly noted, I'll let sleeping dogs lie. I will for sure be replacing all the O-rings, gaskets, oil seals, and anything missing or bad.

Boomer343 said:
I would also suggest doing the mods to improve the oil flow at higher rpms.
Click to expand...

Perhaps my Google fu is not up to snuff... What sorts of mods?
 

CB350 oil transfer piece - with pictures (also applies to CB250)

Hi all, Was sent a set of 350 carbs to modify plus, the oil filter cover. Actually took measurements of this one as the clearance between sliding oil transfer piece and delivery to filter seemed smaller than usual? Anyway, oil delivery hole to centrifugal filter varies between 0.250" and 0.280"...
www.vintagehondatwins.com www.vintagehondatwins.com
 
Thinking about the silver curved item…
this is in the clutch oil pump side cover right.?
So maybe if it is Ali it has broken off from the oil centrifugal cover on the side case?… or…..
personally I would want to seek out from whence it came and to see if there is another part of it it that area.
taking the clutch basket and oil pump assy off will give you eyeball access Into an area where the kick start lever and gear change apparatus lives. There are plenty of place in that are a small piece of debris can hide.

regarding the crank case windage plate, when I did mine I removed it and dugout well hardened oil sludge.
had to use a sharpened screw driver as soaking in diesel, WD40, Kero wouldn’t move it. I was concerned after spending lots of dosh on the pistons and valves I would ruin the engine if a small piece of the crud broke off later and went around the system. Maybe even block the crank big end and main bearings oilways.
it is quite easy to remove and drilling and taping the previously riveted stands for 5mm cap screws.
I posted how to do this in the CB350 section here. I still haven’t figured out why Honda used two machine screws and riveted over the other mountings. Bizarre.
cheers
 
I found my original post.

GaryJames said:
decided to start cleaning up the engine cases I have had vapour blasted.
Starting with the bottom case.
The Vapour media contains extremely fine particles of glass suspended in some sort of semi oily solution, so making sure any residue if this does not remain in the cases as it will get carried around in the nice clean oil immediately after the first start and will abrade bearings and bushes quick smart!
I was worried that some residue was hiding under the oil splash plate. Squirting a high pressure host down the sides didn't seem to be flushing anything out so I decided to remove the plate.
For others who have contemplated this here is how I did it.

First to remove the tops of what looked like to me as aluminium rivets hammered through the oil plate into the case.
There are 3 "rivets "and 2 screws holding the plate on my engine.
I could not move the "rivets" so decided to carefully drill the tops off with a large drill.
This worked great, the plate sprang away and I discovered that the "rivets" are actually part of the case casting. little spigots of Ali that have the tops hammered to hold the plate.
Fortunately there is plenty of casing to drill and tap to take a 6mm machine screw same as the the other 2 screws.
Drilling and tapping the centre one was easy, but the corner ones took a bit more time. Had to resort to a hand drill with a small chuck as the drill press chuck impacted the casing.
It would have been okay to do it in the drill press if I had some long drills.
Similarly with tapping, had to use a 4" adjustable on the 6mm tap, 1/4 turn at a time. None of my small sockets fitted the square head of the 6mm tap, metric or imperial.

Drill size for 6MM x1.0 thread is 5mm.
Holes drilled to 20mm depth.
Used an intermediate tap.

The object of removing the oil plate was to see what residue from the vapour blast remained.
I am glad I did this a there was a lot of semi dried grey sludge in there. It wasn't all Vapour residue as some of it would have been accumulated oil sludge, but enough to cause friction problems in the bearings etc.
The underneath of the Plate was very rusty so that is sitting in a Vapour Rust bath presently. it will take a few days to clean up.

Since I am replacing mushroom headed "rivets" ( which are about half the head height of the 6 mm machine screws I will need to install the plate with the screws then trail fit the crank assembly to make sure the rotating bits have plenty of clearance over the heads of the screws.

I will report on this after the oil plate is ready to install.

View attachment 18337
The mess I found in the bottom, Mix of Vapour Blast residue and old oil sludge
View attachment 18338
Rusty bottom of the splash plate
View attachment 18340
Method of tapping corner holes 1/4 turn at a time
View attachment 18341
After the sludge has been cleaned out. Much better.

Cheers

Gary
Auckland
NZ
Click to expand...
 
GaryJames said:
Thinking about the silver curved item…
this is in the clutch oil pump side cover right.?
So maybe if it is Ali it has broken off from the oil centrifugal cover on the side case?… or…..
personally I would want to seek out from whence it came and to see if there is another part of it it that area.
taking the clutch basket and oil pump assy off will give you eyeball access Into an area where the kick start lever and gear change apparatus lives. There are plenty of place in that are a small piece of debris can hide.

regarding the crank case windage plate, when I did mine I removed it and dugout well hardened oil sludge.
had to use a sharpened screw driver as soaking in diesel, WD40, Kero wouldn’t move it. I was concerned after spending lots of dosh on the pistons and valves I would ruin the engine if a small piece of the crud broke off later and went around the system. Maybe even block the crank big end and main bearings oilways.
it is quite easy to remove and drilling and taping the previously riveted stands for 5mm cap screws.
I posted how to do this in the CB350 section here. I still haven’t figured out why Honda used two machine screws and riveted over the other mountings. Bizarre.
cheers
Click to expand...
Probably for the same reason planes use rivets and not screws ..... . Rivets do not allow movement. Screws and bolts do. Honda did not see a need to remove that part and took steps to keep it in place whether for case strengthening, vibration control or whatever reason the engineers found.
I have a scope I can put down to see under the tray. I'm into double digit rebuilds of 350 engines. Never had an issue getting it cleaned out.
The bottom case has several compartments to trap and hold sludge. The screen on the pick up is fine mesh. I think your worries on chunks floating around destroying things are misplaced.
 
Thank you all for your help and insight so far!

I've solved one mystery:

IMG_1188.jpeg

The aluminum fragments are pieces of the oil spinner, specifically the lip that's supposed to hold the circlip. Unsure if this breaking let the circlip escape, or if the circlip being left out at some point let things rattle enough to break these bits off. If the former, I probably have a circlip floating around somewhere, which is a scary thought.

As for the kickstarter... its circlip was firmly in place, and in fact all the pieces shown on the parts diagram appear to be accounted for. The mechanism seems to be basically working — it disengages when fully up, and can turn the gear when engaged — but the teeth look pretty worn, and it's pretty easy to get a half engagement where they slip past each other, which seems to account for the slipping / ratchet-stripping behavior while everything was together. Also — this amount of play can't be normal, right? Does part of the spring assembly that goes on under the right cover hold it from sliding back and forth and/or wiggling side-to-side like that?


IMG_1179.jpeg

Lastly... my bike's a K2 (engine number 2001907), and while I'm not missing any pieces in the schematic, I'm a bit confused by the fact that two of the pieces don't quite seem to match it.

Screenshot 2024-07-09 at 4.56.10 PM.png IMG_1173.jpeg IMG_1172.jpeg

The shaft doesn't have that wide flare-out right by the number 6, and the alignment of the hole flats with the protruding arm on the ratchet is about 90º off of that in the drawing. Mind you, this kickstarter did previously work (before it eventually started slipping), and I have no particular reason to believe it was ever replaced. Is this just due to incremental design changes?
 
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Regarding the kick starter shaft, Honda changed the shaft to beef it up a bit but never updated the drawings in the parts list.
They seldom updated the drawings unless it was a major change or a new part.
 
I have my replacement parts, have *finally* finished cleaning off all the baked-in gasket (geez), and am now cleaning up the valves and pistons.

Now, this might be a stupid question... The valves respond all over to a magnet, as one would expect of steel, except for the actual valve portion (not the stem) of the exhaust valves. I know the manual says parts of the valves are coated in stellite, and I know stellite is nonmagnetic — but it just seems odd to me that, if that's what's causing it, it would be apparent on the exhaust and not on the intake. Is this normal?

And another question for when I start putting this all back together — any recommendations for/against putting anti-seize on the crankcase bolts? If I do add it, should I err on the low side of the torque values because of the reduced thread friction?
 
I asked that same question about my valves not being magnetic and apparently there is non magnetic stainless steel, see google. As for anti seize I believe the consensus is heck yes use it to make it easier to disassemble later. Others can chime in if there are times not to use it on case bolts.
 
I know plenty of stainless steels are nonmagnetic, but I doubt that specifically the heads of the exhaust valves are stainless welded onto steel stems, unless someone has more info about that. The manual just says they're "high grade heat resistant steel and those areas which are subjected to wear are faced with stellite." I wonder if for whatever reason those parts specifically needed a thicker coating of stellite... or if more of it's worn off the intake valves?
 
CrazyChucky said:
I know plenty of stainless steels are nonmagnetic, but I doubt that specifically the heads of the exhaust valves are stainless welded onto steel stems, unless someone has more info about that. The manual just says they're "high grade heat resistant steel and those areas which are subjected to wear are faced with stellite." I wonder if for whatever reason those parts specifically needed a thicker coating of stellite... or if more of it's worn off the intake valves?
Click to expand...
Even with a heavy coat of Stellite the magnetic qualities would remain, I would suspect non magnetic SS valve head welded to the stem.
 
Since this thread has evolved from removing the engine to rebuilding it, I edited the title accordingly for future search purposes.
 
Thanks for the moderation assistance! I was kinda meaning to ask, actually — being new to this forum, I see the long build/restoration threads as well as shorter topic-scoped questions, and I'm not super clear on the etiquette around the distinction. Should I keep asking questions / posting photos here as I go, for instance, or is it more useful to start new threads as things arise?

And speaking of things arising, do I need to hone the cylinders now that I'm putting in new piston rings? I sadly don't have ID gauges handy and dial calipers aren't precise enough to tell me much of anything useful about the bore diameter, but to the eye they look like this:

IMG_1248.jpeg

P.S. Here's a glamor shot of the extremely high-tech valve removal tool I custom fabricated. 😉

IMG_1238.jpeg
 
Sorry if I missed this in the thread or if you already know all this but sounds like you just want to put new rings on the pistons that came out of the engine and cross your fingers that there is not too much cylinder wear. If that is the case be sure at a minimum to check the ridge ring at the top of the cylinders. A quick way is to drag a fingernail from inside the cylinder up and if your nail catches where the shiny area stops you probably have ridge ring that needs to be removed or the new piston rings can bump on that ridge and break. Yes I would recommend at least do a light hone or run a glaze breaker in the cylinder or the new rings will probably not seat properly. Honestly I would recommend taking the cylinders and pistons to machinist or someone with micrometers to measure both inside and outside. My 450 was worn way more than I would have expected just by looking at it.
 
CrazyChucky said:
Thanks for the moderation assistance! I was kinda meaning to ask, actually — being new to this forum, I see the long build/restoration threads as well as shorter topic-scoped questions, and I'm not super clear on the etiquette around the distinction. Should I keep asking questions / posting photos here as I go, for instance, or is it more useful to start new threads as things arise?
Click to expand...
It's fine for now. As long as the questions stay focused on the engine rebuild it can stay right where it is, but we'll deal with that as things progress.
CrazyChucky said:
P.S. Here's a glamor shot of the extremely high-tech valve removal tool I custom fabricated. 😉
Click to expand...
Well, that's ingenious and looks a lot more professional than this one my father welded up a long time ago.

spring comp.jpeg
 
CrazyChucky said:
I have my replacement parts, have *finally* finished cleaning off all the baked-in gasket (geez), and am now cleaning up the valves and pistons.

Now, this might be a stupid question... The valves respond all over to a magnet, as one would expect of steel, except for the actual valve portion (not the stem) of the exhaust valves. I know the manual says parts of the valves are coated in stellite, and I know stellite is nonmagnetic — but it just seems odd to me that, if that's what's causing it, it would be apparent on the exhaust and not on the intake. Is this normal?

And another question for when I start putting this all back together — any recommendations for/against putting anti-seize on the crankcase bolts? If I do add it, should I err on the low side of the torque values because of the reduced thread friction?
Click to expand...
Yep, take 10% off the torque values, particularly with reused fasteners
 
Thanks y'all!

Man, if only I still worked at a machine shop. I don't feel any ridge ring at the top of the cylinders — there was some gunk there, but I cleaned it off with brake cleaner and it feels completely smooth, with no detectable transition. I imagine I should be able to find a local machine shop that has telescoping gauges and a larger micrometer than my 0-1"... I suppose I will at the very least order a hone, while I'm getting the rings.

Do piston ring pliers make things enough easier to be worth it? The one I broke this time was the oil ring, and as I understand it the newer-style assemblable ones are way easier to get on.

ancientdad said:
Well, that's ingenious and looks a lot more professional than this one my father welded up a long time ago.

View attachment 34887
Click to expand...

Honestly I was thinking of making something about like that when I realized that, hey, it's essentially a big clamp. I have big clamps! 🙂

Yours does have the advantage of not having to hold the piece of conduit and the sliding bottom end of the clamp in place while getting the initial tension on, as well as more access to the retainers on top. (The main advantage of one was it took maybe five minutes to make.)
 
I have a tale of misadventure to share. Don't work on your bike if you're feeling distracted or rushed by anything else. Especially not on a part that involves wet adhesive.

I got the two crankcase halves together, but as I was tightening one of the last bolts, I heard and felt a pop. There's no way I could've stripped the threads, I think. Then I see this:

popped.jpg

I'd gotten everything install and aligned right... except for the registration hole in the bearing on the end of the driven shaft. It wasn't where it was supposed to be, so when I tightened down the bolts, the pin that's there in the crankcase pushed up through the back of its hole.

removed.jpg missing.jpg

When I saw that I'd broken part of my crankcase, it felt like the bottom fell out of my stomach. Thankfully, in situations like this, I know to put it aside and come back to it with a cooler head.

Upon reflection, this isn't a part that should (normally) receive much of any stress; it's just there to hold the pin in place. So... as much as it pains me to say as an actual welder... I JB Welded it back in place. :ROFLMAO:

The next time around, I sorted, labeled, and dry fit all my bolts and bolt holes ahead of time, set my torque values in memory, and made sure everything was 100% ready to go so I wouldn't feel stressed futzing about while the Honda Bond was setting.

bolt holes.jpg bolts.jpg

And wouldn't you know it, this time it went together without incident.

together.jpg

The only remaining evidence of my shame:

repaired.jpg

This was all from a couple of weeks ago, and I've been too busy since to do anything. But now I'm stuck at home with COVID, so it's on to cleaning the pistons and honing those cylinders.
 
You're not alone, it's easy to do especially when distracted. As long as you are sure that the locating pin is fully into the bearing outer, you'll be fine. Once the pin is in place it only has a little bit of side load on it at times but it won't go anywhere. Hopefully you got good adhesion putting that cap back on with JB Weld.
 
Thanks, yeah that's what I figured. Since nothing should be able to apply load in line with the pin, nothing should stress the repair. With no AC TIG welder handy, and not wanting to distort things with heat even if I had one, I figured this may be one of those rare cases where JB Weld is in fact the best tool for the job.

clamped.jpg

I cleaned both surfaces thoroughly with acetone and left the parts clamped overnight, so it should be on there good.
 
Getting the pistons cleaned up, and I have some more questions for y'all knowledgeable and helpful brains. First, is it important to get every last bit of black off the tops? What's left seems really in there.

pitting.jpg

Is this layer of burned-on oil on the inside an issue? Seems like it would take some doing to clean out of there.

inside.jpg

I've read that it's very important to get all the deposits out of the ring grooves, so the new rings can seat properly. I've been spraying brake cleaner and scraping in there with a piece of an old ring. I still see discoloration in there, but it's getting to the point where I'm worried about scraping away more than a negligible amount of aluminum. Should I keep working at it till it's fully clean and shiny in there?

grooves.jpg

Now, for "You can never make one trip to the hardware store" territory... in looking ahead and buying my gasket kit and O-rings and oil seals, I totally missed that the piston pin clips would need to be replaced. So I'll have to get some of those. While I'm at it, I've seen competing advice online about whether or not one should automatically replace the pins themselves or not. Mine mic well within service limits — right at the upper end, in fact. They do have discolored rings on them, though. When I slide one into its hole on a crank, there's the very slightest bit of perceived play by feel. Thoughts?

pin.jpg
 
CrazyChucky said:
Is this layer of burned-on oil on the inside an issue? Seems like it would take some doing to clean out of there.
Click to expand...
Nothing to be concerned about, new pistons will look that way soon enough.
CrazyChucky said:
I've read that it's very important to get all the deposits out of the ring grooves, so the new rings can seat properly. I've been spraying brake cleaner and scraping in there with a piece of an old ring. I still see discoloration in there, but it's getting to the point where I'm worried about scraping away more than a negligible amount of aluminum. Should I keep working at it till it's fully clean and shiny in there?
Click to expand...
That piston looks good, the most important thing is that the rings can fully compress but not get stuck in the grooves.
CrazyChucky said:
Now, for "You can never make one trip to the hardware store" territory... in looking ahead and buying my gasket kit and O-rings and oil seals, I totally missed that the piston pin clips would need to be replaced. So I'll have to get some of those. While I'm at it, I've seen competing advice online about whether or not one should automatically replace the pins themselves or not. Mine mic well within service limits — right at the upper end, in fact. They do have discolored rings on them, though. When I slide one into its hole on a crank, there's the very slightest bit of perceived play by feel. Thoughts?
Click to expand...
I always replace the pins, anything you can tighten up in the way of tolerances in the top end is a good thing for longevity.
 
Has anyone checked if it's snowing in hell, or pigs are flying? It seems the cheapest wrist pins I can find are on Common Motor, of all places.
 
CrazyChucky said:
Has anyone checked if it's snowing in hell, or pigs are flying? It seems the cheapest wrist pins I can find are on Common Motor, of all places.
Click to expand...
LOL That would be an unusual thing for sure, but much like their starter clutch repairs parts for the 350, they are competitive once in a while. You know, the old blind squirrel finding a nut thing.
 
Getting to the home stretch! Cylinders honed, pistons ringed and pinned on, and studs reinstalled (I ended up having to take them out to successfully scrape off the old gasket).

261DBB4A-60CD-4E72-9851-BB521BDC571A_1_102_a.jpeg D249FA3E-02FE-4D20-BAC9-828FA58AE3D1_1_105_c.jpeg

Eagle-eyed among you may notice the rings are just randomly arranged right now, but I read through this thread and plan to do that before I put the cylinders on.

Now, I've been reading on here and elsewhere, and I'm honestly bewildered by the sheer variety of differing opinions and recommendations about what to do with the gaskets in the top end stack. Dry? Grease? Oil? Tiiiiny thin bit of sealant in important spots?
 
The gaskets are installed dry. You can add just a thin smear of HondaBond around the rear outer stud holes for additional sealant for the oil ports, very thin as too much will cause blockage.
 
I'm almost there!

IMG_1540.png

The engine itself is fully reassembled, just need to get the carbs and exhaust and whatnot back on it. Unfortunately I also need to wait for a new set of points to arrive — not sure how I overlooked inspecting those earlier. I've come up with an interesting mystery in the process.

IMG_1539.png Screenshot 2024-10-13 at 8.26.50 PM.png

The heads of the mounting screws are in pretty bad shape, and one's threads just gave out too — definitely need replacing. Looks like they're part #27 in the parts fiche. The parts manual (from the library here) describes this as a 4x5 hollow pan screw, and says there are two of them for all models, including my K2. (Can't tell if the points shown have the lower holes or not.)

1728866105061.png

Mine are about 5.7 mm long, are definitely not hollow, and obviously there need to be four of them.

1728866294288.png

And PartZilla has five different versions available! Even a hollow and a (presumably non-hollow?) version with the exact same part number. I assume any of the first three should work for me — and that the 1A is the latest revision — but I'm still curious about this. Did some models have hollow screws for some reason? And does anyone know if the quantity in the parts manual just wrong, or if there's a story there?
 
Now that I think about, it might be possible to clean these points up. There is some pretty deep pitting, but I don't know if there's any particular limit to how much material I can sand down without causing an issue. As long as I get them flat and conductive and they can still open and close it should be okay, right?
 
For the points its a dance between pitting, rub block wear and space in the adjustment slot.

Quality points with proper maintenance and lube can last a long time. Be sure the point faces are parallel ( as possible) after filing with a proper point file or what I use now, a diamond disc meant for a dremel tool .... just by hand not with the actual dremel tool.

Buy all the screws and be happy .... LOL
 
Points come with the needed tiny bolts, nuts and insulators that attach the electric leads to the end of the springs and the upright plates, down near where the number 280 is stamped. They aren't in your photo but be sure you have them and that all the pieces are assembled in the right order or you'll short out the system. Only people with the finger size of a 4 year old can put these together without a lot of cursing.
 
If you can find one, sometimes it's better to just buy a complete points plate with wires, then you start fresh with everything new including the felt for lubrication and all the fasteners. Not cheap though, here are a couple

www.ebay.com

NOS Honda CB350 CL350 SL350 Contact Points Breaker Plate Assembly | eBay

<p>This NOS Honda CB350 CL350 SL350 Contact Points Breaker Plate Assembly is a highly sought-after item for motorcycle enthusiasts. It is compatible with Honda bikes and has a manufacturer part number of 30200-286-004. The brand is NOS, ensuring quality and reliability. </p><br /><p>This...
www.ebay.com

www.davidsilverspares.com

David Silver Spares

David Silver Spares Honda Part Number Search
www.davidsilverspares.com
 
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