Triumphrat

sucker

I bought a 2001 bonneville a few months ago and it's never run quite right. I've done some research and am trying to rule out one thing at a time. I replaced the pickup coil and it helped a little but still not right. So I bought it with a keihin cr35 in it and I'm not sure if it was ever jetted right since its always been in Denver at 5280 feet. It appears to be running pretty rich, the plugs are really dark. The main jet is a 110 and the pilot is a 55 but it came with spares of 115 and 58. I assume the previous owner tried to rejet it. My question is how can a find decent starting point of what sizes these jets should be. It would be great if I know how they would set it up for this altitude if I bought it new. I also moved the needle from the notch second from the top to the top notch and it still seems rich.

Any help would be appreciated. I've already found a lot of good info on this site. This is my first bike so I'm learning a lot.


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Arkwright

I'm certainly no expert and just beginning to understand my own Bonnie after a couple of years of ownership.

However, I think the 55 pilot jets are way off the mark. I believe 40 or 42 was the standard when the bike was built.

I'm not sure whether elevation has any effect on pilot jets, but if it doesn't then I think changing them would be first on my 'to do' list.

I'm sure others with far more experience will be along soon to help you out.

Askari

I believe that the CR35 can be pretty hard to set up, there seem to be a lot of people with issues. I have a friend with them on his thruxton and after a lot of work they now perform very well. His is 865 so settings wont help.
As there are a few successful owners i think you might need to give a bit mnore info:
Exhaust type.
Filtration.
Not sure how the 35 are set up but if not linked like my fcr you might need to balance them as well.
Might be worth searching the stickies.

SCbonneville

He's running CR carbs, not the stock CVK's.... jets and sizing are totally different... so are the needles and their adjustments (notched w/clips)...

SCbonneville

A couple of things to consider here..

CR 35's are fine carbs but have pretty much been supplanted by the FCR line... So finding a lot of knowledge on their jetting and the effects of elevation, may be limited..

Your best bet would probably be to contact either Carlos @ TPUSA or Mike @ BellaCorse for recommendations and a good starting point for your situation/elevation... Either one should be able to get you in the ball park... Mike has a good bit of experience with the CR's... I'm sure Carlos does too... I know he's got the FCR's down pat...

If I remember correctly, the CR's were typically set up with 55 pilots... at 5500 ft. they're probably on the large side.

I would also pull one of the needles and get the alphabetic marking/code off of it as knowing what needles you have will affect jetting choices or tell you if you if you need a different needle profile.

Be sure to let them know what you intake configuration is (pod filters?), the exhaust system on the bike and the typical/average elevation range you'll be riding in.. You should be able to cover the pilot jet selection range with two sizes (ie" 55 & 58's ) and it would be a good idea to get main jets one size larger and smaller than the recommended size... This should give you what you need to cover pretty much everything you might need. Also, having a couple of needle shims wouldn't be a bad idea as they can be handy to fine tune needle height settings between clip slot adjustments... a shim will give a half step movement between slots...

Also, google "tuning Keihin CR carbs" and there is a lot of information on what affects each adjustment makes and the ranges of tuning overlap (how jets size/screw settings/needle profile-height/clip setting-shimming interact) are... After you get things set up, and you feel it's running pretty well, you should consider finding a good shop that does dyno tuning. Armed with your extra jets and shims, I'd then go get things dialed in on the dyno...

sucker

Thanks for taking the time to respond guys, I really appreciate it.

SCbonneville, thanks for the suggestions. I have found a lot of information on jet adjustments and have learned a lot but I'm not convinced 100% jetting is my problem. Some of my symptoms sound like it's lean and others make it sound like it's rich...more so on the rich side. I just wanted to get a set up that should be close and wanted to make sure my set up wasn't way off. Like I said I'm a noob so I have to go by people's descriptions of sound and other things so it isn't exact.

I guess I should have added the other stuff you asked about in my initial post. The airbox was removed and it has individual K&N air filters. The needle has 8151 stamped on it I believe. I honestly don't know if these are the stock mufflers or not. How would I tell that?

I've seen a couple of things about balancing the carbs and removing the air injection and I don't really know what that means. I thought the air injection was only needed in California but I have two little black nipples on the side of each carb and I don't know what they're for. Do I need to cap those off? Seems like when I rev the bike one of them sucks air and the other doesn't. There isn't supposed to be a hose of some kind connecting those to "balance" the carbs, is there? I'm in IT so the lack of diagrams and documentation on these carbs is driving me crazy.

Thanks again for your help.