85 Big Red 250 Dies

[gewash76]

I just coated the fuel tank on my Big Red and cleaned the carb during the 4 days I had the tank off curing. Now when I start it up, it idles smooth for about 5 mins then suddenly dies. Then after choking it and trying to start it for a few minutes (5-10), it finally starts up, idles perfectly for 5-10 mins, then dies. There are no gas leaks, the air intake tube is on tight and I have an inline fuel filter in the gas line. It also revs up fine just like it always did then just dies as if I shut it off. One thing I did notice was that when I coated the tank some of the coating got on and probably inside the gas cap. Could it be something as simple as the gas cap causing this?

[Tecate Karl]

Yes if it got in to the breather hole blocking it at all would cause this try removing the gas cap and see what happens.

[Taiser]

...or a piece of crap floating around and getting stuck in the fuel line. How much fuel is in the tank when it does this? If it's full, it will run a very short time, almost empty and it will run a bit longer if the cap vent is plugged.

[mtsnieg]

I would think it's not a good idea to coat a tank with the cap on. Think about it, shaking it up, getting the coating ALL around, it's gonna get on the cap fo sho, and seal it up.

[gewash76]

I think I may have just found the problem. I decided to test the fuel cap vent by disconnecting the fuel like and seeing how much gas flows with the fuel cap on. When I switched the petcock to the "on" position, there was a little small stream. Just for the heck of it, I turned the little valve to the opposite direction facing away from the "on" position and gas flowed fine. I reconnected the fuel line and tried starting it again. Before I could finish turning the key all the way, it started right up and kept running. I'll probably replace the petcock, but that seems to be the issue. I'll take it out tomorrow and run it for an hour or so, but it sounds like that's the issue.

[Tecate Karl]

did you try wiith the cap off too just to see what it would do.

[gewash76]

Yea, it does the same thing described above with the cap off. So I think the cap is going to be fine. I think it's just the petcock acting up.

[tri again]

I've had a few 250 model fuel shut offs NOT line up.Off may be on and on may be 1/2 on.

Don't forget that little screen in the sediment bowl too.

I has one with a semi submersible piece of crap float up periodically and plug the flow

[Xhumeka]

I'll state the obvious just to make sure - do you have enough fuel in the tank??? :)

Sounds like when you switch to Reserve, everything works fine. And if you never had a problem with the petcock before, maybe you're just low on fuel!

[atc200xkid]

check the little screen and try to blow out the little pipes going up from the petcock into the tank, mine got plugged once

[ailll1]

Was the petcock on the tank when you coated the tank? I'm guessing you coated the INSIDE of the tank with some sealing stuff? If the petcock was on the tank, sealant got into the petcock and now blocks the gas...
I know thats obvious but maybe thats what you did wrong.

[gewash76]

The petock and the little screen that the petcock fits into were both removed when I coated the tank. I have the tank well over 1/4 full right now so the fuel level shouldn't be an issue. I didn't think to check the little pipes in the petcock before I put it back on the tank. I'll have to check that. Also, there was some white looking gunk down in the petcock beside where the little pipe comes out of it. I cleaned as much of it as I could get out with some thin wire, but there was still a little bit left. But I figured if it was working before it will probably continue to work. But now I see that theory has completely blown up in my face. lol

I'm gonna try to find something to soak the petcock with and maybe that will make it work right again. Worst case scenario would be to put a new one on it.