Total Motorcycle Community Forums

I am brand new to the forum and motorcycles. My brother called me a copule of weeks ago and said, "you want a motorcycle, I have one for you if you want it." I said sure. Now I am no mechanic but I like to tinker so I thought it would be a fun project. Turns out the thing hasn't been started in 9 years. I may have bit off more than I can chew. Its a 1982 Yamaha Maxim 400.

There was rust in the tank and the carbs/throttle wouldn't move. I took off the carbs and cleaned them out. When I had a key made I noticed there was considerable rust in the tank. Well I put in new gas and just tried to get it started. It did finally turn over. But I knew the tank and carbs needed more attention.

Since then I have taken off the carbs again and cleaned out the pilot jets (didn't do that the first time). I have also changed the oil and got the front brakes to work, they were all gummed up.

Now my question. when I got it fired up the first time I noticed that the air filter was moist. I suppose it could have been from a not so clean carb (pilot jets were still clogged). However is there a bigger problem that could cause fuel to blow back toward the air filter?

Thanks

Was it "moist" with fuel? Or oil?

I had the same problem the first time I fired mine up...air filter got soaked with oil. Turned out to be an overfilled oil tank (overfilled by the guy I bought it from).

I can't really see how blowback could be caused, since the engines vacuum should be in the opposite direction.

But I'm about as new to all this as you are.
Good luck!

I'd recommend putting an inline fuel filter between your tank and your carbs. You don't want rust flaking off and getting in your jets making you have to clean the carbs out again. You can get them for 60 cents at a motorcycle dealer or a small auto one for the same at an autoparts store.

You can get the POR rust cleaning kit for about $35. That will clean the gunk out of teh tank, take the rust off and seal the tank from future rust. A good idea.

My airbox has a vaccum tube running to it. However, the guy who sold it too me had an overflow tube hooked up there instead. There were quite a few reasons that bike didn't run and I got one hell of a deal

It was wet with gasoline. The problem was a stuck piston/diaphram on one side. It wouldn't open to let more air flow through as I opened the throttle. I think that would cause gas to build up and flow back to the airbox. I fixed the diaphram/piston thing and haven't had any problems since.