Hey guys I recently rebuilt my 02 and put a 440 big bore kit into it 12:1 je piston stage 2 hot cam. I have helped my buddy with a few rebuilds and he knows almost everything there is to know about bikes. I trust him a lot. My bike sat a month tore apart till I got everything straightened out with my cylinder anyway we spent couple hrs putting it all back together and when the time came it would not start. We checked the timing 3 times ad each time it was spot on the valves are adjusted correctly and everything. I thought maybe it was my spark. I bought a new battery and still nothing tried a new coil and still nothing not even a pop. I did hear about how someone tried push starting their bike so it was worth a try and what do you know after 3 attempts it started! I was so happy but it wouldnt idle and still wouldnt start with the starter. I know I need to bump up jets but right now im at a 162 main and stock 38 pilot. It runs fine around a 1/4 throttle and up darn thing just wont idle or start. My buddy and I are at a loss of words we have no clue and after about 14hrs or work on it still cant even get it to start by spraying starting fluid in it. Any ideas here. Im really not too happy about it after having dumped 800.00 into it and it wont start on its own.

 

Check your compression while pushing off an than check compression with electric start! If compression is different while electric start than prolly start isn't spinning fast enough! could be starter needs freshing up or starter clutch bearing is slipping with the increase in compression! If the compression is the same then I would do an leakdown test and see if you have an bypass around piston an cylinder.IMO prolly in starting system thou.please keep us updated!

 

My compression was low before it started 60psi put some oil into the cylinder and it kicked up to 90. I know sometimes only way to get it to seat is if you get it running I havent checked it since but seems fine and as far as the starter I put the new batt in and it spins faster than the old one so I figured it wasnt it. My spark is a whiteish blue color fyi

 

Did atv start and idle good before the rebuild?If so than it would have be to something that got re-did! Most the time ignition sparks or no spark or skips sparks if bad, also IMO if ran fine before an just sit for an month ignition prolly good! If you had an peak voltage tester to see what the peak is at plug, should be 12,000 to 15,000 volts! But most people don,t have that! IMO sounds like your compression is still an problem! with an high compression setup your still very low! I wish you would try the test that I had mention in the the first post! This will help single out some things, don.t use the oil in cylinder while doing the test! The idle i think will take care of its self when we get compression up! I have started an 100"s of atv's up after rebuilds an does fine, IMO you got starting issues with the starter clutch or values leaking[but if value worked look before rebuild than why did they change if they did at all] so this is why the test first test posted is important! Please keep us updated after this test....P.S Did you try an new spark plug?

 

The bike ran great and idled great before the build. Ill check the compression this weekend as its the only time I get to work on it. The guy that sleeved my cylinder put the piston and rings in (he is a atv mechanic every day) so if its still a compression problem he is def going to be redoing it for free at least while I watch to see if he messes anything up.

 

Ok thats fine! I do atv's and motorcycle everyday also, I do it for an living also! Just keep us updated the next time yal work on it!

 

Double check the spark. I believe this ignition system only fires when the starter button is released. Cranking and cranking without letting off the starter button will get you nowhere, not sparking the ignition. A tight engine on this style ignition system may not be free enough to fire the ignition before the spark is tripped, until the fresh engine components loosen up from break in, yeilding rotation to the timing trip point. The piston basically stops from high compression before the ignition trips when letting off the starter button... hence why it starts when kick started (force to push it past compression AND timing magnets or as we cal it, trip the magneto ignition). I'll double check the stator/ignition pick up style in the service manual to make sure I am right on this one. LOL wrong every now and then but not often.. I believe this is the style of ignition system here and is most likely causing the grief... Some magneto ignition systems are wired this way (cutting the ignition while starter is in use) as the magneto style ignition also works as a generator and can backfeed through the electronics causing damage to their ignition components... you might have to install an offset crank flywheel keyway since the stator timing is unadjustable, after making sure advance weights and springs are in proper working order...

~ Gimpster ~

 

Update:

Well I messed with it a little today and also did a compression test now down to 10-20psi which for some odd reason one of my valves are bent(you can hear it when you ride it). Not sure why but my brother in law had the same problem none of his valves were bent then he put a big bore in and one of his valves bent and we replaced it and it was fine. So im at a loss here im going to get all new valves and springs and go from there if the compression doesnt come back up my cylinder is going back to the guy and he is redoing it. Not to mention I had to fix my truck this weekend so my luck seems to be at a all time low.

 

Glad your making progress! Good Luck

 

Dont know if I would call it progress but ruling things out lol