CL 175 K0 Restore. The addiction is real

Grumpybugger

Grumpybugger

Veteran Member
Joined
Sep 3, 2023
Total Posts
241
Total likes
293
Location
NW Oregon
When I picked up my CB 360 a couple years ago, I was just looking for something to tinker on during the winter, and keep me busy. I had no idea it was an addictive habit. Now I know. So I’ve been on the hunt for another project for a few months. As some of you have seen, @DieselSaves has been trying to thin his herd for a while…….which meant a trip to Kalispell…..to which my wife said…”sure!” Before she could change her mind, we jumped in the pickup and headed to Montana. I had SL 175’s in mind when we went shopping, but the little red sloper caught my eye. Don’t ask me why, but it just kind of spoke to me. I knew the downsides of the Slopers……one year only, and parts are going to be hard to come by…..but he’s got two! AND he found a spare engine…although a K7,which I’ve discovered has interchangeable internals.
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Since returning I’ve been immersing myself in all things sloper and 175 here on the site. This is a long term project. I’m in no hurry and plan on doing things right. @Flyin900 is the standard I’m shooting for…….I hope it’s half as good a build
Preliminary inspection shows some good, some not so. Pretty sure right side plug is cross threaded. Engines are free. Pretty certain the two will make one good one, and with patience and luck, find the missing bits.
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Would like to add that meeting Scott…@Dieselsaves was a treat. Very hospitable, and a wealth of knowledge. It was definitely worth the trip.
 
Grumpybugger said:
(shameless site promotion)
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I love it!
Grumpybugger said:
Would like to add that meeting Scott…@Dieselsaves was a treat. Very hospitable, and a wealth of knowledge. It was definitely worth the trip.
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This is what we're all about here and every time a couple of members get together and make a deal, it helps keep these bikes on the road and generate more fun here. (y) Very cool.
 
With a parts bike your golden!

The orange one looks pretty complete. I spotted a few key items around the battery box that are small but important parts that are still there. You have two air filters intact which is a super bonus, even if they are used.
The broken?? kickstarter shaft will be a case split for a replacement and hopefully your spare motors have a good donor piece.
Interesting that your carbs have an air inlet hose off the filter and a screw adjuster? where it connects on the carb body. That is different than the one I sold which was a very early production bike with motor #802, or the one Joe and I built for him last year. Honda was definitely changing/updating things even on a model that was a one year only bike it appears.

When you get further along the strip down if you have a L side frame of an old air filter that you may consider selling. I could use one for the CL160 build I am doing for Chris.
If I can assist with any questions on the bikes, I do have a little experience with the model.
 
@Flyin900
I haven’t pulled the side cover off the grey bike yet, but can see looking through the frame the air filter is in there. Not sure the condition, but if it’s frame only you need, then done deal. It’s yours. in fact I’ll send em both if you want.

Soon as I get the cover off, I’ll send you pictures of it.
 
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Grumpybugger said:
@Flyin900
I haven’t pulled the side cover off the grey bike yet, but can see looking through the frame the air filter is in there. Not sure the condition, but if it’s frame only you need, then done deal. It’s yours. in fact I’ll send em both if you want.

Soon as I get the cover off, I’ll send you pictures of it.
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Darryl,

I will take whatever you have there filter wise. If the pleated paper media is still there all the better. I am searching for a L side one new still. Which is like searching for a needle in a haystack. I was able to find a NOS R side from CMSNL on sale off a CB125. It looked right in their picture, so I took a chance and it fits the frame perfectly. The L side I still need and anything you can spare on these filters I will gladly take and reimburse you too.
 
Slowly making my way around the bikes. No real disassembly yet. Taking lots of pictures and notes. Couple of interesting discoveries, and I’m sure there will be more……

Front axle is installed one direction on the orange bike, and opposite on the grey one. 🤨
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I also find it interesting how the two bikes compliment each other……what one lacks, the other seems to have, and vice versa. Very fortunate in that regard.
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Any suggestions for best way to safely remove the rubber knee pads on the tanks without damaging them?
 
Had some vinegar left over, so filled the tank to begin the cleaning process before my order of Deox-C arrived. Good news is looks like tank is going to clean up nicely. Currently soaking with Deox.

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Slowly disassembling the parts bike. Taking advantage of being able to practice a bit and learn how these things are put together. IMG_6118.jpeg

Next up is drop the engine. I’ll build a platform to place under it and hopefully slide it out without too much fuss. Then dismantle the rest of the bike.
 
ballbearian said:
Loosen all the cross head screws in the side covers, while engine is stable in the frame, with a JIS Vessel Megadora Impacta screwdriver from amazon. Best $20 you'll spend.
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Ditto, but don't stop with the screws in the side covers. Now is also the ideal time to loosen the screws on the bearing set plate for the shift drum as well as the screws for the neutral switch. We're not in a race but I seem to be a day or two ahead of you with my sloper so I know this from recent experience. Seems like we're in this together. A few winters ago Teebo and I were struggling through our Black Bombers in near perfect lock step and it was nice to know there was someone else in the same boat at the same time.
 
ballbearian said:
Loosen all the cross head screws in the side covers, while engine is stable in the frame, with a JIS Vessel Megadora Impacta screwdriver from amazon. Best $20 you'll spend.
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Great advice. Hadn’t thought of it, but sure woulda hit me when I was trying to disassemble it on the bench. 😳
Troy said:
Ditto, but don't stop with the screws in the side covers. Now is also the ideal time to loosen the screws on the bearing set plate for the shift drum as well as the screws for the neutral switch. We're not in a race but I seem to be a day or two ahead of you with my sloper so I know this from recent experience. Seems like we're in this together. A few winters ago Teebo and I were struggling through our Black Bombers in near perfect lock step and it was nice to know there was someone else in the same boat at the same time.
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Thanks Troy. I figured you’d race ahead of me, but it dawned on me you’re also working on the moped with your son👍. BTW is awesome. So I guess misery will love company on this journey!
 
I like to heat the JIS screws with a pin torch first. Not a must do! I have found if they have sat for a long time they can suffer from galvanic corrosion on the threads. Even with the impact driver, they can still strip a little on the head area. Where the heat helps break the surface tension on the JIS head and the threads.
 
It is a small butane torch available from many suppliers. A much smaller version of the large propane torch set up. It may not be called a pin torch I may have attached that name. Since the flame is smaller yet still very hot. It is more suitable for smaller jobs vs. a bigger propane torch
 
Grumpybugger said:
Had some vinegar left over, so filled the tank to begin the cleaning process before my order of Deox-C arrived. Good news is looks like tank is going to clean up nicely. Currently soaking with Deox.

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Slowly disassembling the parts bike. Taking advantage of being able to practice a bit and learn how these things are put together. View attachment 52690

Next up is drop the engine. I’ll build a platform to place under it and hopefully slide it out without too much fuss. Then dismantle the rest of the bike.
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I have in the past had great success using an electrolysis setup to remove tank rust. It leaves a blackish rust free surface, no worries about flash rusting. It's not as easy as just pouring in an acid solution but is kinda fun. All I needed was an old school 12v car battery charger and a steel wire coat hanger.
 
Tony Clifton said:
I have in the past had great success using an electrolysis setup to remove tank rust. It leaves a blackish rust free surface, no worries about flash rusting. It's not as easy as just pouring in an acid solution but is kinda fun. All I needed was an old school 12v car battery charger and a steel wire coat hanger.
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Others here have done it too, I've never tried it but I have one I might do it on.
 
Finished disassembly of the parts bike, except for front and rear wheels……wanted a roller, not a carrier😏.
I knew this old girl had a rough life, it for the life of me, I don’t know how you can bend the clutch rod like this…IMG_6132.jpegIMG_6133.jpeg

Luckily when I pulled the cover off, the ball bearing fell out and bounced up and down between my feet, so I was able to corral it before it rolled off into the unknown regions of my garage.
The motor is stuck, so I set it aside for now, and started on teardown of the “good”? bike.
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Mostly as expected …..IMG_6184.jpegwith a little PO electrickery for fun🙄. Next on the list is drop the motor and and see where that leads. Then start the real work……cleanup.
 
ancientdad said:
A thrown chain was probably the culprit on the clutch rod.
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I never thought of that, but I haven’t seen the things you have. 😂. I’ve been around trucks and equipment my entire life, and I just can’t get my head around the abuse and neglect people willfully inflict on anything mechanical.
 
That is an amazing double bend in that rod. I had one break in two on my CB450 many years ago, but the two pieces were still straight. It happened while I was about 15 miles from home and I felt lucky to be able to limp it home. Found the broken rod the next day when I investigated the problem.
 
Grumpybugger said:
I just can’t get my head around the abuse and neglect people willfully inflict on anything mechanical.
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I certainly haven't seen it all, but I have seen my share of mechanical horror stories. Blatant neglect is the biggest challenge these bikes usually suffer, people buy them and have zero understanding of their non-automated, all-mechanical design due to the age and era they're from and never bother to learn if they should address any maintenance needs aside from maybe an oil change. That's why we so often see things like cam chain grooves worn into the cylinder and head from not adjusting the chain for years, centrifugal oil filters packed full of metallic goo, engines all sludged up internally when rebuilds are needed, worn splines on things like the kickstart shaft because they don't understand the need for a tune-up while kicking the guts out of it trying to start it, and the shift shaft because they don't pay any attention to the looseness of the shift lever, among a dozen other things that are normal and typical maintenance items. And they say ignorance is bliss.... maybe until the bike quits running and now it costs you a bigger fortune to repair it. :rolleyes:
 
Someones been inside here before…..

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Be interesting….hopefully not horrifying…to see it when it’s apart.

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That swing arm is going to fight me to the end, I’m afraid. Doubt it was ever serviced, as stiff as it is. Three foot long, half inch drive breaker bar barely moves it. Heat the frame?

These are the motor mount bolts. Ones on left from parts bike, which is a lower frame number. I just found it odd theyre different…….parts manual shows ones on left.
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It's interesting that you can see the crosshatch on the cylinder walls, must not have run a whole lot after those pistons went in.

I suppose heat might help loosen up the swingarm — there's no grease fitting, I guess?
 
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stl360+450 said:
It's interesting that you can see the crosshatch on the cylinder walls, must not have run a whole lot after those pistons went in.
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Kinda what I was thinking. Especially given the shiny tops of the pistons. Fingers crossed it’s just a cleanup in there. We shall see.

stl360+450 said:
I suppose heat might help loosen up the swingarm — there's no grease fitting, I guess
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Didnt see one or feel where there might have been at some point.
 
That large swing arm bolt isn't set up for any grease fittings which is odd. Since there are the rubber seals and a outer plastic bushing that are part of the swing arm internals. Heat at a higher temp isn't likely a good option without damage of the said rubber and plastic bits.
You could try a heat gun on the two front metal H sections of the swing arm, since there are also two metal bushings internally in there that are likely frozen onto that large bolt. An impact wrench gun should be able to spin the bolt in the housing and maybe some PB Blaster can help release the bolt and swing arm situation.
 
Other than the stubborn swing-arm, the bike is stripped. I’ll let it soak a few more days, and if it still won’t budge, then we’ll take it to work. Reluctant to use more heat than my heat gun produces.

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Shocks going to need some serious love. Need to re-read flyin900’s post from his 160 build.
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Took a quick peek under the valve cover……cams shows wear. No surprise there. Didn’t go any further just yet, but I’m sure rockers will too. Chain and tunnel looked good.
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So the large bolt through the swing arm is frozen and won't spin when you hit it with an air impact gun with a 6 point socket on the head end of the bolt? With the bikes possibly outside or in a shed for many moons, they maybe got some moisture in there.
The top end of the motor looks good though.
Hopefully you don't have the one fork from HE double hockey sticks. That one fork seal on the CL160 was a real bear and Paul had to resort to a double cut carbide bit in his cable fed dremmel style tool.
 
Flyin900 said:
So the large bolt through the swing arm is frozen and won't spin when you hit it with an air impact gun with a 6 point socket on the head end of the bolt? With the bikes possibly outside or in a shed for many moons, they maybe got some moisture in there.
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I don’t think my gun has quite enough oomph….plus I’m using my pancake compressor because my big one died. I don’t think I’m getting enough volume, so I’m not totally surprised. I will take it to work after it’s soaked a couple more days and hit it with a bigger gun. I’m sure that’s all it should take. I can rotate that bolt by hand with enough leverage. Just can’t spin it fast enough.
Flyin900 said:
Hopefully you don't have the one fork from HE double hockey sticks. That one fork seal on the CL160 was a real bear and Paul had to resort to a double cut carbide bit in his cable fed dremmel style tool.
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Fingers crossed. I’ve already gone back and reread your past entries.
 
Pecking away little by little, stealing a little time here and there. Frames are finally completely stripped and swing arms removed. A couple weeks of soaking and a 1/2 half inch impact finally got me there.

The motor off the grey bike is seized, and I’ve been tearing it down to salvage parts I was originally going to split it because I need a kick start shaft. Upon closer inspection though, the splines are not in great shape. Luckily when I bought the bikes, Scott……dieselsaves threw in an extra motor, albeit a K7. From what I’ve researched, the shaft is the same.

I dove a little deeper into the good motor……New pistons…..looks like a couple new rockers….It looks to me like someone rebuilt this motor and broke the kick start shaft trying to get it started. Those pistons don’t look like theyve ever seen a spark……

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Cam looks borderline to me…… if not across the border. 😏

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Next issue is separating the barrel from the lower case. She’s pretty tight. Any suggestions appreciated.


Also, on the seized motor….. pistons are stuck tight….but barrel is loose. So the pistons and barrel move up and down……..I’m trying to figure out how to free them without any unnecessary damage. Again……any suggestions would be greatly appreciated.
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ericfreeman said:
Might be a good time to send that cam to a custom grinder who can do a performance grind on it.
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Yeah, there are few things more satisfying than an engine making horsepower at higher rpm than it was originally tuned for. The Megacycle cam in the 200cc 175 engine in my father's drag bike build in the early '70s pulled strong to 11,500, and if you didn't shift in a hurry in the lower gears it easily went 12,000
 
Think I got here just in time…….IMG_6243.jpeg

Barrel looks okay…no pitting. Hopefully just a hone.
Im going to hold off splitting the cases of the good motor for now and concentrate on opening the seized one. I’d rather have the practice on that one before I commence on the good one.
Did spend a minute trying to make this thing easier to work on……IMG_6244.jpeg
 
Decided to hold off fighting the seized KO motor because the kick start shaft I need is in much better shape on the K7 motor that came with the bikes.

After a week soak in Deox-C I was able to get the K7 motor apart, but it was a battle.

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Trying to work the speedo drive off the cam……Well it came off 😳

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Didn’t lose much…..cam had a broken tooth already….
I was able to salvage the kick start pinion….which was the goal all along.
Today I split the case of the ”good“ motor. Things just got a bit more interesting….
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Locating pin for the kick start. And it’s broken off in there ☹️.
So now we’ll tackle getting the seized KO apart. Hopefully I can make one good motor out of the two…….
 
Curiosity got the best of me…..I popped the cases apart on the seized motor to see what I had. Looks good to me.
Now to get the rest of it apart.
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Well having two of everything is a must on these old bikes. The cam that broke looked pretty rough anyway on the lobe areas? Moisture up in the top end? A lower replacement case that the has a good pin mount for the case and kick starter shaft.
 
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