Bonneville America Forums Forums Technical Forums General Tech Not again! Spit and sputter.

Last fall, I was convinced the coil was going bad because the bike started spitting and sputtering. Turned out to be water in the gas tank. The gas tank and carbs were drained and cleaned. That seemed to do the trick for a while. Seafoam was used when it would act up. I Thought the problem was finally solved until yesterday. After 15 miles, the bike started acting up. The tank was topped off with premium and some Seafoam. It never cleared up and the bike limped home. Which leads me to ask:

What are the chances of getting bad gas twice- from different locations.
Could the gas cap have a leak? Rainstorm, or while washing?
Could it be electrical this time around?

I'd start at the tank and VERIFY clean gas and work down all the way to the bowls. Then start with a small quantity of CLEAN verifiable gas and if she still sputters, well, there ya go,chasing electrons.

Put some seafoam in the gas. I sware by it...

Check and make sure that you didn't knock an ignitor wire on the back of the ignition coil loose or off when you were removing and installing the tank. I did that once and it drove me crazy trying figure out what was wrong.

You'll never know until you pull the petcock and insure the former water incident hasn't compromised the screens. Same with the hidden filter at the T junction between the carbs. And, yes, bad gas twice wouldn't be out of the question either.

Thanks guys. I don't have the know-how to chase electrical gremlins or carb work. The tank will be drained and new gas will be added. If that doesn't work, it'll go to the shop.

Bite the bullet and drain the tank so you can remove (gently) the entire petcock assembly. Really, it's the only way you can be certain.

I've always been sceptical (afraid) of pulling petcocks, seems they sometimes weep afterwards. I've always pulled the tank flushed with good gas or mineral spirits, poring out through the fill hole. Flush the petcoch in reverse, tank upside down on a bench, repeat rinse. Use a can of computer/camera air to blow petcock. I've use carb cleaner, but only on tanks to be repainted. You get the idea, it's like back flushing a swimming pool filter.

I've pulled my twice, never had any issues, maybe just got lucky.

Okay, I'll do it the right way then. Thanks for all your input.

Why not attach a hose to the petcock and let the tank drain in a container? If it drains slowly, the petcock is plugged then you know you have to pull it.

Okey dokey. Nice idea. I will do that.

You can test the entire fuel run by opening the bowl drains (with appropriate catch cans) and opening the petcock. It's pretty easy to see if one line is flowing better than the other or if total flow is restricted.

Don't discount a sticky tip over valve located in the vent line along the backbone down tube. More than once these valves have gotten gummed up and caused intermittent fuel starvation issues.