Gas leaking into engine

mattybpt · Post by **mattybpt** » Sat Nov 24, 2012 12:05 am

I have a CA77 dream that has sat for the past 26 years and I'm trying to get running. i have recently replaced all the fuel lines, cleaned the carb., and replaced the petcock. I filled the newly lined tank and the fuel leaked into the engine block. I unscrewed the oil plug and a gas/ oil mix came pouring out. What do I need to do now??? Any suggestions on possible causes??? Thanks.

G-Man · Post by **G-Man** » Sat Nov 24, 2012 7:09 am

If fuel is getting in to the engine it is getting past the float valve. Check that it seals properly.

Did you change the carb gaskets. Sometimes the modern replacements foul on the float and stop it moving up to cut off the gas.

G

Goodysnap · Post by **Goodysnap** » Sat Nov 24, 2012 8:27 am

Also make sure there is no fuel inside the float. Not nearly as common but it does happen.

mattybpt · Post by **mattybpt** » Sat Nov 24, 2012 10:47 am

I did not change the bowl gasket and there was some fuel leakage from the bowl. The float was slight dented, but it does not appear to be filling up with gas. I will verify that the float is ok. Do you recommend that I get a new gasket? Thanks for the advice at least it gives me some direction.

Rickytic · Post by **Rickytic** » Sat Nov 24, 2012 12:50 pm

G-Man and Goodysnap is right on. Fuel comes from the tank into the carburater float bowls. The only way it can get into the cylinders is past the needle and seat that sits under the floats. If the needle and seat are bad, or dirty, that will allow the fuel to get into the engine. If the needle and seats are good, then maybe you have a hole in one of the floats causing the float to sink and that will negate the needle and seat from working properly. The float/floats might also be stuck with muck and varnish from old gas sitting in the bowl. It would probably be wise to remove the bowl, check the needle and seat, the movement of the float and check to see if the float has a leak. Some have taken the float off, shaken it to see if there is any liquid in the float and some have even weighed them to see if there is a difference in weight if you have two carbs. You might also want to check the float hieght to see that it is properly set. All this you can find using the search function. Look on the left side of your screen, if there is a yellow vertical bar, go toward the bottom and find the search arrow, click on it and type in your key words for your issue and there ya go. If ya still can't figure it out, keep posting and someone on here will help ya out.

Rickytic

mattybpt · Post by **mattybpt** » Sun Mar 17, 2013 1:52 pm

Since I last posted this question I had a friend who is a motorcycle mechanic rebuilt the carb, and had him replace the needle, jets, float, and gasket. When I first put the carb back on it fired up in 3 cranks, and ran fine. Sat for a few weeks, and the gas again had emptied into the engine case. Could leaving the petcock in the on position cause it to leak into the engine? Should I remove the carb again and check float height? I removed the bowl and the float appears to be moving freely. How to I check the needle to make sure it is working correctly? Any suggestions would be appreciated.

G-Man · Post by **G-Man** » Sun Mar 17, 2013 3:10 pm

Always good to switch the petcock to off when you're not using the bike.

Although it's messy. Drop the float bowl the hold the float up with a finger (light pressure) then drop it to start the fuel flowing. You should be able to stop it completely by lifting the float very gently.

G

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