help atc 500

[gasmask]

ok the motor is freshly rebuilt top & bottomend, brand new 39 mm carb from ESR racing. i will try the starter fluid tomorrow...but i put about 10 drops of gas in the cylinder & 10 drops in the carb since it all new, that when it backed fired twice.so i know it getting gas & fire...how can i get it to kick over more that one revolution...lower the compression or what?????

[coyote killer]

It wont spin even with the throttle held open???It should spin a couple of times with the throttle open...

[gasmask]

It wont spin even with the throttle held open???It should spin a couple of times with the throttle open...

NOT EVEN WITH THE THROTTLE WIDE OPEN...JUST ONE REVOLUTION ALWAYS...

[coyote killer]

my 490 wont spin unless i hold the throttle open and then it doesnt spin much....But when everything is right she starts on the first kick,,,,cold or hot....

[coyote killer]

I think youre alright as far as the spinning concern....I'm guessing you have something causing a lean condition since trailprotrailpro getting a backfire....if she starts with the starting fluid then trailprotrailpro probably lean.....if she wont start with fluid then trailprotrailpro rich.....

[gasmask]

OK I WILL try the starter fluid tomorrow...i want to go try it now but it 10:18 pm here. i may try it tonight...in 1995 i had a big bore kit put in a ytz 250. in order to crank it i had to push to crank it...i sent the head back to trinity racing and when they shipprd it back i could kick it over...this bike is doing the same thing that's why i'm focused on compression...

[coyote killer]

OK,,,but before you give up on it compare it to other 500cc 2 strokes....All of them I have seen dont really spin until they fire.....Unlike a 250 thats easy to spin....

[gasmask]

i'm not going to give up just yet.it has taken me 9 month to get this far...now i won't give up until it fires up...so far that's the only hold up now.once it cranks i will have it chromed and polished, new plastic,rim & tires the works...guy around here love to drag race so that's my goal...i have someone willing to build me a wheele bar already...

[x.system]

Instead of starting fluid try WD-40, it works the same as starting fluid but has lubrication.

[200xBoy]

someone probly already said this but pull the carborator off and clean the float type thing. my 200x did that at the dunes and i was so pissed and i ripped the carb off and cleaned it and it ran fine.

[Tri-Z Pilot]

Those 500's can be very stubborn. try bump starting it maybe that will help. If you have dumped gas down the cylinder, and it still backfired, it shouldnt be lean, raw fuel in the cylinder is very rich. One more thing, have you tried a new plug?

[gasmask]

the spark plug, carb etc are brand new...the compression specs. are 7.4:1...i may have to buy a compression gauge to check me compression...if it to much i will have to put another head gasket on it...

[gasmask]

after a long night & alot of advice for you all my atc 250/500 is now running...i when a bought some starter fluid and sprayed it into the cylinder.at first it backed fired 3 times then the fourth time it sound like it wanted to crank. the compression problem is not an issue. the only thing is that when you crank it/ it's more like you have to feel the right crank stroke...after spinnig the engine over bring the kicker 3/4th of the way up the kick the sh_t out of it...that's when it cranks...thanks for all the parts, help & the advice...i will try to post pictures in a few days...

[gasmask]

see help atc 500....thanks everyone

[Tri-Z Pilot]

Oh yeah, you cant just keep kicking a cr 500, you will lose the battle every time. All you have to do is find top dead center, then kick like you have never kicked before, that should do it. Another thing I have heard riders talk about, is to lean the bike to the side a little bit, supposedly it primes it, but I dont know.