CB175 1969

Yesterday I tried starting the bike for the first time with mixed success. It did run, but only if I held the throttle open. I tried to adjust the idle screws and I was able to get it to idle for a short amount of time before it died. Now, I don't have the air-filters attached yet, so that's likely one issue but I think it's mainly the carburetors themselves. I rebuilt the carburetors over a year ago, it was one of the first things I was able to do at the time since I lived in an apartment at that point. I had a feeling I might have put the wrong size jets in at that point so I opened them up again today. Luckily I saved all the old parts to compare to the ones in the rebuild kit. I looked at the original jets I saved and yes, I did install the wrong ones. Now I've installed the same size jets as were originally in the carburetors. I've yet to try and start it again since the change. I'm sure there's going to be some more tinkering that needs to be done before I get it running properly.

I also discovered that the kick starter lever doesn't clear the aftermarket mufflers I installed. I'm not sure what I'm going to do about that yet. I have the electric start but I would like to have the kick-start option. I can't bend the lever as far as I know because I think it's a cast piece. I guess an option is to get different mufflers though I really like the way the ones I have look so I probably won't be doing that. Easiest thing would be to just leave the lever off which I probably what I'll do unless I find a solution.
 
daveythewavey19 said:
Yesterday I tried starting the bike for the first time with mixed success. It did run, but only if I held the throttle open.

I also discovered that the kick starter lever doesn't clear the aftermarket mufflers I installed.
Click to expand...

It did run… YAY! Glad you saved the old carb parts.
Sorry about your kickstarter and mufflers, I’m no help other than bending or denting something, unless you can move a mount?
 
Good to hear you got it running and certainly glad you saved the old jets. I think Richard Pitman used a different kickstart lever on one of his 175s to clear the aftermarket mufflers, check his build threads or PM him.
 
A little bit more success today, got it to idle for longer than yesterday but still dies. My thought now is that there is too much air getting in without the air filters. I reason this because even with the throttle all the way closed, it's idling at around 3000 RPM. I put my hand in front of the intake for the carbs and the RPMs drop. I also noticed some gas leaking from the float bowls at the gasket between the the bowl and the carb bodies. That makes me wonder if the floats heights are wrong (probably). I'll have to check that next.
 
Running without the airfilters wouldn't cause a problem at idle speed. Check that you have enough free play in the throttle cable ie slides bottom out in the carbs.

As for the kick start lever, I fitted a folding one from a pit bike. This should clear aftermarket pipes that don't have the flat on the side. As it happens, the stock lever clears my David Silvers pipes, I was just fed up with it digging into my leg. I've since learned to live with this !

QkfG4OI.jpg
 
The new kick start lever came in the mail today. It didn't fit out of the box because while it cleared the muffler fine, there wasn't enough clearance for it to clear the oil dipstick area that protrudes out form the engine cover. To make it fight I used an angle grinder to take off enough material for it to fit. It was a big pain but I managed to get it on in the end.

20210626_170229.jpg

Also put the seat on. Would like to find some side covers, I heard that the CB175s all have the same side cover mounting points, is that true? Because finding 69 side covers is pretty much an impossibility.

20210620_160920.jpg

Now I need to work out why I haven't been able to get it to idle. The jets are the correct sizes now and I adjusted the float heights per the shop manual. Maybe I have the needles clipped at the wrong level? I would think that it should idle with the carb throttle slides all the way down and the idle screws back out all the way but maybe that's wrong? And how do the air screws effect idle if at all? I'll have to do some more research and fiddling around.
 

Attachments

  • 20210620_160929.jpg
    20210620_160929.jpg
    206.5 KB · Views: 7
daveythewavey19 said:
Now I need to work out why I haven't been able to get it to idle. The jets are the correct sizes now and I adjusted the float heights per the shop manual. Maybe I have the needles clipped at the wrong level? I would think that it should idle with the carb throttle slides all the way down and the idle screws back out all the way but maybe that's wrong? And how do the air screws effect idle if at all? I'll have to do some more research and fiddling around.
Click to expand...

I wouldn't have expected that result from the kickstart lever you bought when looking at the picture but now that it's on the bike I can see the issue, bummer. It might eventually wear a spot in the lcutch cover from laying against it that way.

As for the carbs, no, the engine won't idle with the slides all the way down and the idle screws not touching. Despite the cutaways in the back, they still have to be lifted just slightly by the idle stop screws. The slide needles have zero effect on idle, that's for mid-range from just above idle to half throttle or so. The air screws work when the idle is at or slightly below the FSM spec idle speed (usually around 1200 rpm) by allowing more or less air in to mix with the slow jet-metered amount of fuel. If the idle is above FSM spec range then the air screws stop functioning as adjustments since you get into the slide needle and main jet range.
 
I figured out why I couldn't it idle and it was due to a really dumb mistake. I had the throttle slides in the wrong carbs so they were backwards...whoops. Now I have them in the right way and boom, it idles. Need to do the fine adjustments but at least I finally figured out my mistake. I noticed that the rear brake pedal hits the frame when release, so something needs adjustment there still as well. Probably a lot of little issues here and there but I'm happy to say the engine runs, idles, and shifts at least into first gear and out without an issue. Haven't run through all the gears yet other then when I manually turned the engine by hand and went through them after I rebuilt the engine. Let's hope I didn't mess something up when I put the transmission together.

running.jpg

I took the tank off and decided to make it so I could remove it in the future with gas in it by adding a quick disconnect to the crossover line:

20210716_124429.jpg

Kind expensive for a little valve ($50) but it saves me from having to siphon the tank out or spill gas everywhere when the tank needs to come off again. Also replaced the stock fuse holder with an enclosed one so the glass fuse isn't banging against stuff or shorting on some ground.

I'm going to have to figure out what I'm going to do about the side covers next. I know there are some reproduction covers for later year cb175s but I'm not sure if they have the same mounting points. I also thought of making my own somehow, have to figure that out. I want to do something to cover the little pod air filters I'm using because it just doesn't look right to me with the big black void in the center of the bike.
 

Attachments

  • 20210627_151243.jpg
    20210627_151243.jpg
    408.2 KB · Views: 8
Too bad you don't have the centerstand on the bike, you could shift it through all the gears with it running sitting still. As for the sidecovers, when I look at the later CB175 covers at RetroCB the top tabs seem to be about the same width as the earlier ones, and it wouldn't surprise me if Honda kept the mounts on the frame in the same spots over the years and simply changed the design/style of the covers. Richard Pitman would probably know, he knows 175s very well.
 
ancientdad said:
Too bad you don't have the centerstand on the bike, you could shift it through all the gears with it running sitting still. As for the sidecovers, when I look at the later CB175 covers at RetroCB the top tabs seem to be about the same width as the earlier ones, and it wouldn't surprise me if Honda kept the mounts on the frame in the same spots over the years and simply changed the design/style of the covers. Richard Pitman would probably know, he knows 175s very well.
Click to expand...

The K4 covers are interchangeable with the K6/K7 covers, probably CB200 ones as well.

Remember that the K4 air filter boxes are slimmer than the later ones, so K4 covers don't fit over the K6 filters, despite frame mounts being the same.
 
I finally was able to get my hands on some side covers. They are from a 71-72? cb175 so they fit my 69 more or less. I need to repaint them now but I'm not sure what's the best way to prep them. Anyone have experience painting plastics?

20210917_082027.jpg
 
Judging from the picture I'll say a good sanding with nothing lower than 400 grit. Yeah, I know it'll take forever and a coarser grit will be faster but that also can leave some pretty healthy scratches in the plastic. Do not use paint stripper, most of them will melt the cover. Once you have a fairly smooth surface shoot them with sanding primer and sand them smooth. Paint with regular automotive type paint.
 
Last edited by a moderator:
I got the side covers painted, they're not perfect but they match the rest of the paint job. I need to secure the bottom tabs of each cover somehow since the original side covers that came with this model only had the two tabs and were not as tall. Right now they'd probably fly away if I tried riding it. I also got the bike registered and insured, I just need to have it inspected now before it's legal. I'm hoping it will pass without too much more work needed. If it's not up to muster, the shop I'm going to take it to will have to fix whatever I did wrong. New Hampshire is weirdly strict about inspections considering we're pretty lose with most stuff. Though I think it really depends on whose doing the inspection.

20211003_132915.jpg20211003_132934.jpg
 
Covers, AND the bike look great! Very nice work.


Tom - 1982 CM450E / Midwest USA
 
I like the color, the bike is looking good. If you could snake a long skinny zip tie (or a pair of them) or wire rod through, maybe under the battery box, and drill a small hole in the underside of the bottom edge of each side cover you could tie the bottoms together so they wouldn't lift while riding. Just snug enough to keep them from flying outward on the bottoms, and the tabs on the top would held them until you could come up with a better arrangement.
 
I had the bike inspected and thankfully it passed. To keep the side covers from flying away, I took a piece of fuel line, cut it to length, popped it over the bottom tabs on each cover, and secured each side with a zip-tie. Unfortunately, the side covers also hit the toolbox and there's nothing I can do about it so I removed the toolbox. Anyway, this project is pretty much complete now though I'm sure I'll be tweaking things for the rest of my life. Thanks to everyone here that followed along and helped with your suggestions and answered questions for me. I appreciate it!
 
You must log in or register to reply here.
Back
Top Bottom