setting carbs

martin · Post by **martin** » Tue Jul 24, 2007 8:18 pm

thanks guys for all your help, and thanks to rc46 for phoning me and giving me advise, i phoned stan stevens today, he says standard jetting is fine, 38pilot,135main,he says lean the clip up to the 2nd from the top[leaner]. i have tried that with the pilot screws at all different amounts and it seems worse, above 4000 its fine,but below 4000 its fluffy,if the throttle is pulled hard from tickover,it dies,i balanced the carbs as rc46 said,so am pretty sure carbs are near on balanced, tomorrow i will drop the clip on the needle to the bottom[richest setting]and play with the tickover screws to see if that helps,surly the extra 50cc would mean it would need more fuel.

rc46 · Post by **rc46** » Tue Jul 24, 2007 8:35 pm

stan said make it lean? Serious? Okay i cant argue with that. but i would have thought Bigger motor better porting more fuel was needed so bigger jets? to supply more fuel!

Is she ideling okay Now? Fluffy?

dose she settle down to an even tick over when you rev her?

Let us know how you get on..

mgtkr1 · Post by **mgtkr1** » Tue Jul 24, 2007 9:09 pm

the idea of been a bigger capacity needing bigger jets is a logical way of thinking and sounds the obvious solution to such changes but the kr was jetted rich to begin with as its a road bike and if it had ''on the edge jetting'' when new i dont think kawasaki would feel too keen on the idea of a warranty! back to the bigger capacity/jetting richer topic, the ypvs boys who use 28pkw carbs on there bikes with mild tuning still using an airbox tend to leave the jetting as per kr1 s with good fueling and no problems so what stan said makes sense if you go on what the rd lads are doing aswell. the kr has a larger airbox but that doesnt necceseraly mean it will be leaner as a result, in fact as elf has found out in the past it can cause the bike to run richer due to the change in velocity/airspeed. anyway, stan will of put you right im sure, all the best, matt

rc46 · Post by **rc46** » Wed Jul 25, 2007 1:19 am

Aye, he (stan) would be a bit stupid to recomend the same jets if it didnt work.. I like a safe bike, I have 145's in mine and she runs nice n safe!!!

Except when its spitting its Cir Clips out LOL

the-elf · Post by **the-elf** » Wed Jul 25, 2007 1:25 am

do a search as I've posted the link to the USA site for the carb manufatures a few times before, on there is a chart to help you jet the carbs correctly. If its fine above 6K then the main jets arn't the problem as they only control fueling at very high revs.

personnal I would check to make sure your've not got a blocked or semi blocked pilot jet first. If Stan said that the standard jetting is right and your still having problems then it points to the carbs not being right and blocked jets and or floats ect. are quite a common problem.

martin · Post by **martin** » Wed Jul 25, 2007 10:41 pm

thanks for all your help. have taken carbs apart again, and one of the pilot jets does seem blocked,could nt blow through one,i hope that is the problem, i am going to take my time and balance the carbs as rc46 said with new pilot jets at the weekend,still cant work out stan stevens saying drop the needles to 2nd from top[as standard is 2nd from bottom]but then again he must be right, does anyone know, does it richen or lean turning the pilot screws in. once again thanks to all of you

mgtkr1 · Post by **mgtkr1** » Thu Jul 26, 2007 12:52 am

the pilot jets will be the cause and it will run much better when reasemmbled. had a similar problem at 6k were it would fall into a hurrendous flatspot till around 7-71/2k.

mr_bungholeo · Post by **mr_bungholeo** » Thu Jul 26, 2007 11:40 am

trust in stan...he knows his stuff...heard they need jetting down somewhere.....but as above...a rich mixture will only fowl plugs a lean one will melt your pistons...screwing out the pilots leans the mixture out n in richen's it...

the-elf · Post by **the-elf** » Fri Jul 27, 2007 8:07 pm

#When I was jetting the 35mm carbs I had a simular problem where the bike would tick over but then die when I opened the throttle. This was caused by the primary air screws being too lean. I had to screw them in another turn or so to get it running right.