Honda Atc 70 dies out

[Zooman]

Hi Guys I just found this site
I just bought my kids a 1982 Honda 70 threewheeler and its a fun machine. But we are having a problem with the machine stalling or just plain dieing. The machine will rund great for about 15 minutes and then the engine will miss a few times and die. I checked compression cold and I get 90 psi and after it stalls I get 90 psi.

I thought that after the engine warmed up that much that maybe my compression would be low but its not. The engine also seems really hot when it stalls. I gave the carb a good cleaning also put sume new gas filters on it. I don't have a manual yet but I will be ordering one in a few weeks.

Also what should my carb setting be set at for my idle and air screw?

Thanks the help!
Matt

[Treshombre]

I'm sure you checked the air filter....

But it sounds like your runnin lean, bike is getting to hot and then quiting.

Whats the spark plug look like?

[Treshombre]

Also want to check the following:

Ubstructed cooling fins
Point Gap setting ( .012-.016 )
make sure you have the right spark plug ( CR7HS NGK)
and that it is gapped correctly (.024 - .028 )

To adjust the airscrew you need to get the bike to idle.
once at idle, turn the screw clockwise until the engine speed decreases or begins to miss, note the location of the air screw.
Then turn the screw counter clockwise until the engine speed decreases or begins to miss, note the location of the air screw.

Turn the air screw to a point midway between these two locations.

There isn't a set place like 1 1/8 turns out etc.

Now having said all that I don't think that is the problem.

Your compression should be between 142 -170 psi
you stated it was 90 that doesn't sound good.

check the valve adjustment to see if a valve is staying open a little.

your probably going to want to get a manual for this guy
here's a good site for that and virtually all other 70 parts

dratv.com/engineparts1.html

and no I'm not affiliated with dr.atv officially or unofficially ;D

[Zooman]

Hey thanks for all the tips. I will go over the machine with all the suggestions you have posted. I am trying to get a manual so I can check the valve like you suggested.

I will post back when I get some findings on this machine.
I appreciate all the help, I thought this web site was dead. That link you posted is a great one.
Thanks again
Matt

[Treshombre]

No problem Matt...

Here's another good site for 70 questions....

www.glamisdunes.com/invision/index.php?showforum=50

Also, The Oct issue of Dirt Wheels has an article on adjusting valves...

The valve clearance on the 70 is .002 for both the exhaust and intake

Have fun!