Who can tell me how to ID a specific KEIHIN carb? I have a 1985 Honda ATC 350x with a modified engine in it. It supposedly has a 500cc big bore kit in it of some sort, but I have know way of telling just what size it is, as it was done long before I bought the 350x. All I know is that the engine is between 350cc and 500cc, most likely between 400cc-430cc as the biggest engine kit I have been able to find is a 430cc kit by Powroll. Anyway, back to my question. The carb that is currently on the engine is a KEIHIN and the only numbers that I can find on it are DG8AAAG, above those numbers it has PE, and nothing else. I need either a new cap and rebuild kit for this carb, or help in selecting an appropriate replacement for it. So can any of you Masters of ATV maintenance please let me know what carb size and model number I have, and or a good replacement carb for my 350x engine with the given overbore of between 350cc to 500cc? How critical is it to get the exact size carb given this range of engine size? Please help, as I am dead in the water until one of you generous mechanics can help me either ID my carb, or pick out a good replacement.

Thanks so much,
Brian

 

You might try emailing or calling these people ,I guess carbs are all they do.

http://www.carbparts.com

and www.sudco.com has a expoded view of a PE 20 and 36


charles

 

If Your engine is bored like you said Powroll sells a carb for it.I just put a 430 kit in mine but am just rejetting the stock carb.

 

Thanks for the info guy's. I think that I am going to have to go with the carb from Powroll. I just wish I new what size carb was currently on it. I also wish I knew what size overbore was on it. It doesn't seem like there are very many choices out there for the 350x. I wish there was some way to tell if my overbore kit was from Powroll.

I guess the main concern will not be what size carb I put on it, but rather if that carb is jetted correctly or not. I guess I will just install the carb from Powroll, and then take it down to the Honda shop and have them jet it right for me, as I have never done it. I guess I will get it tuned up while I'm at it.

Truck, how do you like that 430cc kit from Powroll?

Thanks again.

 

The kit looks great the engine is just sitting on the shelf waiting for my 4 wheerler conversion to get here,man it's tough just looking at it setting there.While I had it apart i relaced everthing in it.It should be a real strong engine.The difference in pistons is amazing!Can't wait to here it run!!!

 

you have a Keihin 'PE' series carb. I had one on my 83 ATC250R. If you feel like pulling the head off the engine, its not that hard to measure the bore and stroke..then you could forumulate the CC's

 

Dill, that sounds very tempting. I have never done much work on motorcycle engines though. Is it simply just remove and replace, with only a head gasket needed to put it back together, or once the head is off will it require any kind of adjustment, like valve, or timing adjustments after I put it back together. Also, what would the formula be to calculate the cc? Just take the piston to bottom dead center and measure the bore and stroke, then multiply the two? Any specific info would be appreciated.

Thanks,
Brian

 

Dill, also is there a way to tell what size PE carb it is?

Thanks again,
Brian

 

sure, pop the head off and put a new headgasket on. Just mic the bore size and the stroke. the formula is boreXboreXstrokeX.0007854=cc

you could also mic the small end bore of the carb (I believe thats where its measured at)

PE carbs are really old technology tho, a 39mm Keihin FCR would probably be a better choice for that motor.

of course, by removing the head you'll have to remove the cam and cam chain (overhead cam engine) so you will have to reset the cam timing, probably a good time to check the valves and what not inside anyways, if you've never had it apart. A nice Clymer or Honda repair manual would be a good idea here [img]i/expressions/face-icon-small-smile.gif[/img]

 

Hey Dill thanks allot. I have a Honda service manual for the 350x, but I don't have a Micrometer to measure the bore and stroke. Do you think that a tape measure would be accurate enough to get me close, or do I really need a mic to make it worth taking the engine apart?

Also, do I just bottom the piston out, then measure the distance from the top of the piston to the top of the cylinder to figure out the stroke? I just want to make sure if I tear into it, that I have the tools and knowledge to measure it right. Also, once I tear into it, would you suggest cleaning the combustion chamber and top of the piston if it needs it before I put it back together?

Thanks again,
Brian