[slicnic]

hey guys wondering if somebody could help me with my 07 450x. Not long after new i put a jd kit through it 165 main red needle mid position,fuel screw, n was amazed how much better it went everything was perfect. now a few years later iv been having problems with the jetting cant seem to get it right was stalling lots wen braking hard around corners also noticed that by screwing fuel screw right in bike would still run but it shouldnt do that n it never did when i first installed the kit,it also now has this annoying flat spot at about quarter throttle sort of splutters a bit then when you gas it it goes good, ive now tried the 162 main not much difference, somebody told me could be the pilot jet too big so i put in a smaller the stock was a 145 now running a 142,was a bit better still done it and still didnt stall after screwing fuel screw all in, i tried moving the clip one position lower still not better .I just can understand how it used to run perfectly but now a few years later its so different its not valves or anything like that they are all good .do the carbs n jets just wear out over time i dunno but it really bugs me i love this bike it has about 12,000km everything is good except for this dam jetting issue any help would be greatly appreciated

[crfsonly]

check two things. one, the AP diaphragm. these are known to degrade over time. also, check your floating valve plate and seal. make sure the plate is install correctly and the seal is in good condition (lifting the plate) and is install correctly. since you are going to be in there you should just replace it. also, if the bike sat with fuel in the bowl you might want to replace the pilot jet just to make sure it's not clogged or partially closed with bad fuel.

ken

[slicnic]

thanks for your reply ken. i checked the diaphram looked fine the pilot jet is a new one so it should be fine but i checked it too was clean . The bike still runs runs with the mixture screw all way in and that is now with the smaller 42 jet as well shouldn't it stall the engine ? Im about to check the float now but iv never touched that so i should be right i think. Its got me stumped ?

[crfsonly]

thanks for your reply ken. i checked the diaphram looked fine the pilot jet is a new one so it should be fine but i checked it too was clean . The bike still runs runs with the mixture screw all way in and that is now with the smaller 42 jet as well shouldn't it stall the engine ? Im about to check the float now but iv never touched that so i should be right i think. Its got me stumped ?

if it was sitting with fuel in the carb then the pilot jet is going to be clogged or partially clogged. even if you can see light through the jet that doesn't mean it's not partially clogged. even the smallest obstruction will cause starting, idling and off-idle bogging. i'd replace with new just to eliminate this as a possible culprit.

second, if you used carb cleaner to clean the carb you should replace the floating valve seal with a new one. these seals break down with the use of carb cleaner and affect idle and off-idle performance.

also, drop the float bowl to inspect and clean.

ken