CRF hard starting. Need help!

[400exMO]

My Crf450 is terrible to start. I just shimed the valves to exhaust- .011 and intake- .006. I have screwed with the jetting quite a bit but it does not seem to solve the starting issues. I have moved the needle clip all around. I have tried 170 and 180 main and 42 and 48 pilot. No combo seems to help. I have a UNI air filter and HMF exhaust.

To start it first time cold, it must be pull started behind another quad. After that it will kick start but takes anywhere from 3 to 30 kicks. Some times it will not kick over warm. I believe the hot start mechanism is working correctly. I just put fresh 91 octane gas in it.

Anybody have any ideas to help get it starting better? Or a starting point on jetting.

[jrspawn]

Could be several things, but from the sounds it might just be a little wore out. How fresh is the top end? Have you pulled the carb apart and gone over everything also?

Thank you
Justin

[deathman53]

Did you have this bike long?? When I got mine it was very similar to start, my friend could start it first kick every time. I had to learn how to start it, I was used to riding old school 4 strokes and 2 strokes. Once I got the hang of it, starts easy. What condition is your plug?? When mine gets hard to start, the plug is fouled out, did you try this already?

[400exMO]

Just put a new plug in this afternoon. The carb has been gone through last month, but I am going to do it again today just to make sure. The top end has not been touched since I bought the engine.

[pro-rider46]

double check to make sure that the decompression is setup correctly

[400exMO]

Decompresser is setup correctly. From what I have gathered at TT my intake valves are the problem.

I pulled the head and intake valve seats appear worn. Black exhaust fumes where the valve should be seating.

I'm gonna get a faction mx stainless intake valve kit. Have my valve seats recut and go from there. My exhaust valves look good. My guides also feel good.

[loboboy]

repalce all the valves and make sure you get the cam timed right. If it is retarded 1 tooth that will make it very hard to start. Also if you replace the vlaves you will need the spring kit to go with it. If you don't the valves will float since the stainless valves are heavier than the Ti valves. Do your homework with a reputable engine builder before you start this upgrade or your headaches will get worse.