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Discussion Starter · #1 ·
Greetings,

This may be my last attempt to find answers here. I've had zero replies to my last couple of threads.
Anyway that's ok, ill figure it out. I built the stock Kiehn 747's on this 75 CL360, with kits from collective motors. I also replaced the diaphragms. The left side is much richer than the right, it idles fine sometimes, and accelerates great once the throttle plate open a bit. Ive built more concentric than VM carbs, and usually when the idle is irratic it's an indication the slides are bad and the carbs need to be replaced. Im not going to give up on these, yet. The slides seem to rise and fall uniformly. I have 150lbs compression on both jugs. I have set the timing and adjusted the valves. I am using the stock air cleaners, and shorty mufflers with thumb screw snuffernots. I don't think back pressure is my problem. I think it's in the idle circuit on the left carb. Any suggestions of what to look for when I tear these down tomorrow? Thanks for any reply. I feel like I did when I moved to Illinois from Oklahoma 35 years ago. No one spoke to me, and they still still think I'm a hillbilly. Phil
 

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I'm not sure why there's been a lack of responses to other threads, I don't get too involved with the 350/360 stuff due to lack of real knowledge. If these carbs have multiple idle circuit ports at the throttle plate there's a distinct possibility that on of those is clogged. I know the VB carbs on the SOHC 400/450's have 3 sequential ports and it's not uncommon for one of those to plug up. If the slow/idle jet is removable then I'd also be looking at the size of the holes, people use a "jet cleaner" which is actually a fine reamer that's used to clean acetylene torch tips. Keihin jets are nice in that it's straight metric sizing. a#35 jet is .35mm, 100 is 1mm.
 

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I felt a bit the same way a few months back when I had a mysterious oil issue on my DOHC 450 engine after a complete overhaul during my build. I struggled with it from many directions and at the time, I felt I wasn't getting as much help here as I'd hoped for but the truth is, mine was a strange and unique problem and all the advice I got was the usual, general stuff that I'd already double and triple checked and was sure was okay. In retrospect, it would have been next to impossible for someone not in my garage with me and looking at all that I looked at over 3 cam follower/cam bearing disassemblies to see or think of something that I missed - and in the end, I'm pretty sure it really was something I missed. Miracles don't usually happen from the freely-offered information given here, but there are daily successes from the knowledge base here and it's always given in good faith and with a real interest in helping someone get through the moments that are difficult for them. Yours may well be like mine was... and since you are the only one who can truly see what has been done, it might take you grinding it out - much as I had to - until that comes to light. I absolutely know the feeling... and if there was something I/we could tell you that would solve it for you, we absolutely would.
 

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Discussion Starter · #4 ·
Thank you for the replies. It is sometimes difficult to find a reliable forum. I joined here because you all show up on many of the searches Ive done on this bike. Thanks again.Phil
 

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Nice Bonnie in your avatar. '69?
 

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I recently rebuilt the carbs on my CB360T. The forum was advising that the main jets should be #110, but I found that it would not run properly above 3000 rpm. Took me a while to figure out that it was running too rich.

I changed the jets back to #100 and it cured my issues. I'm also going to mod the stock air filters by replacing the paper medium with UNI green foam, in hope to get more air flow and a leaner burn.
 

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Discussion Starter · #7 ·
I pulled the carbs, double checked that everything was clear/clean, set the float height to 18mm (from 16), and it runs much better. I still have some work to do on the exhaust, it's too dang loud. It has shorties. I'm going to repackage the insulation.

Thanks dtsm, that bonneville went to Australia. I'm going to pick up a 62 bonneville basket case next week. This little Honda was a break from the British. I tell ya, the japanese build em right, it's like, wow, look at how they did that.

Thanks for the replies,

Oh yeah kycb, a little rich, is better than a little lean, in life, and air cooled engines.
 

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Float height is still too low. You want a minimum of 19mm but I find 21mm better to lean things out a little on the ~4,000 rpm transition to secondary main jet. When it's running right it will ave similar performance to a 500 Triumph but obviously way less torque at low rpm
 

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10drum... glad to see I'm not the only one making a lateral move to these well engineered bikes...
They are a DREAM to work on compared to Brit bikes..
but I love them both!
Got a question about the slow idol jets.. are they straight passages like the primary? Or are they blocked off?
Got jet info.. it is supposed to be straight through ..gonna soak it and see what happens
 

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pilot jets are blocked by a screw in plug on 360's. They 'feed' from primary main jets so total fuel at high rpm is primary plus secondary main jet only. Majority of 'two jet' carbs (pilot and main jet) only have a tiny amount of fuel added at high rpm by pilot jet. (I know I worked on some 2 jet where pilot was fed from main jet although I forget what they were? )
 
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