help atc 500

[gasmask]

today i tryed cracking my atc 500 project bike...when i kick it over i can only get one revolution out of it...do i have to add another head gasket or another gasket at the bottom of the cylinder...it will back fire but only kicks over once...any advice is accepted...

[H.M.F.I.C.]

Those 500's are a complete biatch to start. If you are out to make sure that it runs get sombody to pull you off. I had a cr500r dirtbike and that is prettymuch the way I started it anytime it was cold. Once it was warm I could start it but even then it was stilll hard.

[ClayW]

Well, I have a XR500R Dirtbike, and it can not be started without using the compression relief valve. My bike has a small lever that mounts on the handlebars under the clutch lever. THe cable goes down to the right top side of the head. If im not mistaken it holds the exhaust valve open. Mine starts on the first kick after the compression stroke. Most of the time I get on the bike and slowly push the kickstart down until I feel resistance. Then I pull the valve open and hold it open, and kick it one time. This gets it off the compression stroke. Then I just kick it once and it fires off. It can not be cranked by a HUMAN!! unless its off the compression stroke. My wife actually tore ligaments in her ankle trying, by accident. She thought she had it off the compression stroke, but it took one more kick. She let it have it and tore ligaments. Im a big guy 6'3" and 285lbs and I cant come close to kickstarting in unless its off that compression stroke. Maybe you need to hook up a compression relief valve. Sounds like you dont have one.

CLayW

[ClayW]

It will also back fire a bit it you dont kick it over fast enough. Its more like a poping sound coming out of the muffler.

ClayW

[OldSchoolin86]

Gasmask, is this a 2 or a 4 stroke?

[ClayW]

Has to be a 4.

[OldSchoolin86]

I've been gone for awhile so I may have missed an old post but why would it have to be a 4?

[H.M.F.I.C.]

It is a two-stroke.

[coyote killer]

my yz490 just gave me the same problem....it had water in the gas.....now it starts first kick.....

[OldSchoolin86]

Thanks H.M.F.I.C., that's what I thought it was.

[ClayW]

Sorry about that. The guy I was thinking about, converted his 350x 4 stroke to a 500 4 stroke. Mine is a 4 stroke.

ClayW

[gasmask]

it is a 1985 cr 500 2 stroke engine...i cleaned the gas tank out 3 day ago & it sat in the shed until today...fresh gas & 2 cycle oil. as you already know if i remove the spark plug i get all the revolutions i need, but when i put the spark plug in i only get one...is that cause buy to much compression.i remember reading one forum saying that they used 2 head gasket to lower the compression...

[gasmask]

Gasmask, is this a 2 or a 4 stroke?

2 stroke cr 500 honda

[coyote killer]

it is a 1985 cr 500 2 stroke engine...i cleaned the gas tank out 3 day ago & it sat in the shed until today...fresh gas & 2 cycle oil. as you already know if i remove the spark plug i get all the revolutions i need, but when i put the spark plug in i only get one...is that cause buy to much compression.i remember reading one forum saying that they used 2 head gasket to lower the compression...

All that it took to make my perfect YZ backfire and not start was about 3 small drops of water in the float bowl.....I got just a couple of drops out of the tank too.....If thats not it then look for something that would cause it to be lean.....

[coyote killer]

u could also try starting fluid just to get it started the first time....