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Flyin-Low
05-05-2007, 05:13 PM
My quad is taking FOREVER to start when its hot, just cranks over and over and over and then will slowly start up, and the idle is really choppy. It also backfires almost every time I try to start it after sitting for a while.

What could it be?

-Martin
05-05-2007, 06:42 PM
Check your valve clearance.
Flyin-Low
05-05-2007, 07:20 PM
What are the intake and exhaust tolerances?
Duke450r
05-05-2007, 07:24 PM
Decompressor clearance to tight.
chad502ex
05-05-2007, 07:48 PM
dagnabit,.... Ti valves... as mentioned check your valve lash..
Flyin-Low
05-05-2007, 09:19 PM
Originally posted by chad502ex
dagnabit,.... Ti valves... as mentioned check your valve lash..

What about Ti valves?

Does this problem really sound like the valves?

And can someone give me the measurements for intake, exhaust and decompresser?

-Martin
chad502ex
05-06-2007, 07:58 AM
over a long period of engine run-time, Ti valves begin to cup causing improper valve to seat contact. This implies that over time the Ti valves will not seal in the engine compression required for startup. Overall engine performance should drop too.

the intake valve clearance is 0.006"
the EX is 0.011"
decomp is 0.011"
Rulz
05-06-2007, 03:38 PM
Hard starting with back firing is an indication your decompression clearance is to tight!
GIXXER1KR
05-07-2007, 05:51 AM
I had the same issue and it went away with an adjustable A/F screw but i can be the valves.Is the valve clearance the same on the 06 w/ HRC cam!!!