Polaris ATV Forum banner

03 predator 500 wont start

3K views 3 replies 3 participants last post by  Bruce! 
#1 ·
whats up guys new to the forum here...... just recently acquired an 03 predator 500 not running from my buddy.... he said it was running and had a little top end tick from the valves but said it still ran good and he let it sit for a month or so and now it wont start...... I checked the valve clearances and the intake was too tight I could not even get a .002 feeler gauge under it so I got some shims and reshimmed the intake valves (the exhaust was still in spec) got it back together and it still wont start..... if I take the breather tube off the back of the carb and put my hand over the opening while turning the motor over I can feel it sucking and pushing on my hand as the motor turns this is telling me that the intake valves are staying open(correct me if im wrong).... all of the valve clearances were in spec when I put it all back together I don't understand what is going on now.... I am an auto mechanic so I know what I am doing I plan on bringing my compression tester home from work tomorrow to check compression but would like some more insight if anybody knows anything I am overlooking..... any help would be greatly appreciated
 
#2 ·
I have a 03 as well and just spinning engine over with starter I can't feel any pressure pulsing back out. Only suction. I think you are one the rite track in thinking intake valves are open when they shouldn't be. Which could be timing or a damaged/sticking valve. I'm going to have to shim my valves before long how bad a job is it?
 
#3 ·
it wasn't that bad to do but I am an auto mechanic and work with motors everyday so I had a pretty good idea of what I was doing I got lucky and got the specs and timing set right the first time I think that's where a lot of time gets consumed in getting the clearances and timing set right.... im not sure whats going on with this thing hopefully I don't need to rebuild the head or anything but I guess compression check tomorrow will reveal more info but hoping it is something simple.... also when I hold my hand over the carb after a few seconds of cranking my hand is soaked with gas even with the tank off
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top