valves out of djustment running?

[zaxcar1]

i have 2002 426.i think the valves are out. when i start it cold it stalls a lot and wont stay running. i have to restart it 3 time before it will stay running. also when cold it back fires, gives a loud pop. so is this the valves? or something eles??

[KJ790]

If you've never checked the valves, it is probably time to check. They should be checked every 10-12 hours of riding. That is multiple times per season for most people. The popping when it is cold is most likely a jetting issue. The stalling is also very likely to be jetting related.

[patcap]

sounds lean to me back out the fuel screw/pilot a half turn or so and see,my bike was doing the same thing exactly like you said and i put a 42 main instead of the 40 and tinkered withe fuel screw and no more popping and it only takes a minute tops to be idleing on her own.

[todds924]

sounds lean to me back out the fuel screw/pilot a half turn or so and see,my bike was doing the same thing exactly like you said and i put a 42 main instead of the 40 and tinkered withe fuel screw and no more popping and it only takes a minute tops to be idleing on her own.

You are confused. There is no such thing as a 42 main and no such thing as a fuel screw/pilot.

[bboyce]

i have 2002 426.i think the valves are out. when i start it cold it stalls a lot and wont stay running. i have to restart it 3 time before it will stay running. also when cold it back fires, gives a loud pop. so is this the valves? or something eles??

Since you are in MI and it has gotten cold, its a combination of lean jetting and just a cold bike. My bikes valves are in spec the jetting is a tad off and my bike will start run for 3 seconds and die for about 2 times, then after its a little warmer, it will stay running, but wont take throttle for about 10 seconds.

[blue9red9]

bboyce is experiencing the same thing I did last winter. The bike will need a little pilot screw adjustment for the winter or even a pilot jet increase maybe wouldn't hurt. I increased my pilot up one size and it helped a lot in the winter season. How does your bike run once warmed up? That's what really matters. In really cold weather (in VA that's about 20 degrees and below) I have heated my cylinder head with a hair dryer and it helps greatly on the starting and warm up. Don't jump to the worst things first... OH MY GOD IT'S THE VALVES!! but it could be checked.

[zaxcar1]

i was looking at the book and i see the the piolt jet is a 42 thats what i have. it does have a dr.d muffler. should i go bigger?

[blue9red9]

You could go bigger but you need to base your decision on how the bike runs once it's warmed up. Try the fuel screw first. I don't recall my 426 being lean in cold weather like my 06 is or was before the jet change.

[maxtherat]

Sounds like your pilot jet might be partially plugged. Clean it out before you start messing with your jetting. If you think it is lean after that then raise the needle one position(lower the clip). A 42 PJ should be good on your bike.