Fuel leaking when choke is used to start

[GeorgiaYankee]

I'm having a hard time finding where I have some fuel seeping from after using the choke to start on cold mornings. I do have significant cracks in the rubber intake manifolds that I suspect my be letting the fuel weep through, and the leak is up high. Any thoughts?

[dacheedah]

are you using the petcock also?? that has known to drip a couple drops when first opened. The intakes have metal linings in them and if truly leaking would give you running issues. my thoughts

[ragtop69gs]

Don't be so quick to blame the cracks in the rubber manifolds. My '01 RSV manifolds looked terrible, DEEP/Wide cracks on all 4. When I did my valve check last spring I replaced all 4. I cut the worst one in half just to see and none of the cracks were all of the way through.

 

The Venture uses an enrichener not a choke (butterfly) . Look at this fiche view, it may help you to narrow your search.

 

http://www.ronayers.com/Fiche/TypeID/26/Type/CARBURETOR_/MakeID/4/Make/Yamaha/YearID/47/Year/2006/ModelID/1677/Model/XVZ13TFV_ROYAL_STAR_VENTURE/GroupID/340482/Group/CARBURETOR_

[MiCarl]

Even if the carburetor holders (manifolds) are cracked there shouldn't be liquid fuel there. Everything going through there should be fully atomized.

 

Also, there is nothing about the enricheners that would leak fuel.

 

It's much more likely to be a float sticking that shakes loose once the engine starts. A leak at the petcock is also possible if you're turning it on or off. Either problem will keep getting worse until it's a big deal.

[GeorgiaYankee]

Thanks guys, I've not been turning the petcock on and off because of the drips. The bike only shows gas leaking when using the choke. The more choke, the more gas shows up running down onto the crank case between the heads. the rubber manifolds look wet too. I may need to clean everything off well and choke it, start it and watch again. Just can't tell. Are the rubber manifolds under pressure or a vacuum? How about with the choke on?

[RedRider]

The manifolds you are seeing go to the airbox that runs along the center frame rail. They are under vacuum and would not have any fuel in them. Also, don't worry about the cracks. As mentioned earlier, these manifolds have a metal liner and the cracks will not go all the way through. If you are concerned with the cracks (after you deal with the fuel issue), run the bike at idle and spray WD40 or starting fluid at the cracks. If the RPMs change, then you have a leaker. I don't expect you will have any leaking.

 

 

 

Back to the issue at hand. I suspect you have an issue with your floats/bowls/float valve. The overflow is at the top of the bowl so it will appear to be leaking from the top.

 

First step is to drain each bowl. There is a nipple at the bottom of each bowl and a screw that opens and closes this release nipple. Put a short length of clear tubing on the nipple, put the other end of the tubing in a glass jar, and open the screw. Do not have the engine running or the key on when you do this.

 

You may get some gunk out of the bowls. If so, close the release valves and turn on the key to fill them back up and then drain them again.

 

If this does not take care of the problem, I would expect you need to open the carbs, replace the float valves, and set the float height. There is a procedure in the tech section to do this.

 

Good luck and let us know how it goes.

 

RR

[GeorgiaYankee]

so, I've had a bike on the lift for the last week. I took it apart all the way down so I could do its first valve adjustment. 39,000 on it and 5 intake valves and one exhaust valve were VERY tight. Had to order one more shim to finish, no 265 in the kit I borrowed (Thank you Earl !). I took off the float bowls and reset 2 of the floats, were a little high. I may have found the culprit there though... all four O rings were totally dried out and fuel stains were passing over them in places. (Pink residue from the dirty fuel we get now). New o rings on the way. Will let you know if it works when she's all back together.

[GeorgiaYankee]

Here's the latest in this maintenance project turned nightmare... new bowl o rings installed, put the bike back together, and fuel came gushing out of the left overflow once running. Sea foamed and tapped on it, no luck. Carbs back out again. Found cylinder 1 float stuck open. Freed it, carbs back on. Now cylinder 1 and 4 are cold. Poured seafoam/gas down the overflows (getting frustrated now) sat overnight. Ran it like I hate it, and still 1and 4 are cold. Surprised how well the bike runs on 2 cylinders. New spark plug in #1, no change, and I'm getting spark. No fuel getting on the plug. Now floats stuck closed perhaps? Wtf?

[GeorgiaYankee]

The saga...ends.. Woohoo! I can't thank y'all enough for your advice, and for all of the posts I've read trying to troubleshoot for the last few weeks. The latest is, 4 new needle valve assebly's installed in all four carbs, 2 were sticking really bad (closed causing 2 cold cylinders). Put it all back together, and she runs like a champ. Synched the carbs, and went for a quick run. Faster than ever. No leaky fuel using the choke, all is right in the world. I suspect the leaky fuel was the bad bowl o-rings and high float setting allowing fuel to weep out, or the needle valves not closing all the way, and overflowing out of the top of the carbs a little at a time. I hope that's it for a while.

 

Now to figure out what size front tire to get.

[ragtop69gs]

As mentioned earlier, these manifolds have a metal liner and the cracks will not go all the way through.

Good luck and let us know how it goes.

 

RR

 

That is not entirely true. There is a metal liner, but it does not run the full length of the manifold, 1/3rd on each end has the liner, the center 3rd is unlined to isolate any vibration, so it is possible for a leak to develop, but not likely.

 

I had deep cracks and when I changed them out I cut one of them in half, none were all the way through. I have pics somewhere, when i find them I'll post them.

[mike4dodge]

On 11/29/2012 at 5:03 AM, GeorgiaYankee said:

I'm having a hard time finding where I have some fuel seeping from after using the choke to start on cold mornings. I do have significant cracks in the rubber intake manifolds that I suspect my be letting the fuel weep through, and the leak is up high. Any thoughts?

I thought I had fuel leaking because of sticky floats after doing all the seafoam treatment… Went to replace the fuel filter and found the fuel pump itself was leaking in the center and it was just running down the side of the hoses new fuel filter and fuel pump runs perfect no leaks

[saddlebum]

glad you got your issue sorted out.