Leaky carb!

[Hutch]

My carb started leaking about a day ago so I cleaned it out yesterday. I came back out this morning and its leaking all over the floor of my garage again! Its leaking out of the drain/overflow tube. I checked the float, its fine. I dont know what it could be!

 

[slickerthanyou]

It has to be the float!, or the float valve isn't stoping the flow!

 

[Hutch]

I checked the float! theres no gas inside or any thing! What else could it be?

 

[slickerthanyou]

Take the float off and immerse it in gas any bubbles? No... check the float valve, it its not working properly, that is the only thing it can be unless the gasket around the bowl is leaking or the petcock is leaking, or the gas line itself.

 

[slickerthanyou]

There is nothing else! My best guess is the float valve is not shutting the fuel off. may be dirty or worn, or hard as a brick and not sealing.

 

[Hutch]

Wheres the float valve?

 

[slickerthanyou]

where the float pivot point is. I will try to find a pic....

 

[slickerthanyou]

Here ya go, This is not your carb but it's close they are all in the same place!
number 29

 

[Rich]

Do you turn the gas off while its parked.You should always have it off when not riding.Like slicker than you said sticky float or more than likely you need to replace the float needle valve.The float opens and closes this valve to let fuel in.It has a rubber tip that is a wearable part.

 

[Blaaster]

The float level could be incorrect, causing the fuel not to shut off.

There could be some crap in the needle and seat assembly, stopping the needle seating

You could also have a varnish buildup in the needle seat.

Remove the seat from the carb, and thoroughly clean the passage where the fuel line comes in.

Make sure the rubber O ring on the seat is not broken.

Put some toothpaste on a Q tip and revolve it up in the seat , to clean out any varnish.

Re assemble and check the float level, 20.0 to 21.5mm on a stock carb.

Img courtesy Awk08

It is ok to leave the petcock on if you are riding often. No harm will come if you leave it on.

It can become a diagnostic tool, because if you have a problem with dirt of varnish in the needle seat, or a float problem, it will be evident on the garage floor.

If you are not going to ride again for a while, you should turn the petcock off and drain the fuel from the carb bowl.

 

[Hutch]

I just cleaned it out twice in a week, I dont think it can get any cleaner. The needle looked fine when I had the carb open yesterday

 

[slickerthanyou]

May look ok, but the rubber seal on the end of the float valve can wear, and get hard, out of shape even, or the chamber that the float valve sits in can wear enough to let fuelmix leak past.

I bet if you replace the float seal and seat it would cure it. Not sure how many times I have to say it!

 

[Hutch]

ok ok ... where can i get one? Who sells mikuni rebuild kits?

 

[slickerthanyou]

Any Bike dealer, Ebay!

 

[Hutch]

I looked on ebay!

 

[Braaaptor]

Here, read up on this!

http://www.blasterforum.com/do-yourself-20/easy-almost-free-way-stop-leaky-carbs-33335/

You can buy just a new inlet needle and seat if you need them. Most of the time, carburetor leaks are due to an improperly-adjusted float or dirty/damaged needle or seat. Floats can and do fail, but 99% of the time you can shake a bad float and hear gas sloshing around inside one of the pontoons.

 

[Hutch]

Alright, I cleaned out every nook and cranny in my carb today, took out the choke, idle crew, and cleaned the seat and valve out with tooth paste. Its still leaking... Ill have to pick up a re-build kit, how much do they run?

 

[Rich]

You only need the float needle valve as the one you have is problubly just old and hardend.Possibly a new float but you said it checked out.Here is a link for a few rebuild options on ebay.yamaha blaster carb rebuild kit | eBay

 

[Hutch]

Thanks!! Ill have to pick one up this week.