Carb Trouble

[mralex714]

I have an 86 VR that regularly has the carbs overflow. When it does the bike won't idle and poor throttle response. When I got home today i was trying to find which one it was. I took off the air box and found gas pooled on top of 3 of the butterfly valves. I started the bike and opened the throttle and let it close gas again pooled and stalled. When it stop running gas spouted out of the holes on top of the carbs. Can I assume that the ones with the fuel pooling are the ones overflowing? Any thoughts where I should start?

 

Thanks

The bike did this when I bought and I had them rebuilt at a shop. It ran well for a few months and then would do it again. I had the carbs done again and had the floats replaced with new ones and again alright for a while then the same thing, also an additional fuel filter was added.

Edited February 8, 2015 by mralex714

[flyday58]

So no gas dripping out of the overflow hoses in front of the rear wheel?

[mralex714]

So no gas dripping out of the overflow hoses in front of the rear wheel?

 

Gas is coming out of the overflow hoses, it's a pretty steady flow.

[Marcarl]

A good dose of Seafoam or something similar might help seat the needle valves. I would try that first. Seems there is some dirt in the system.

[mralex714]

A good dose of Seafoam or something similar might help seat the needle valves. I would try that first. Seems there is some dirt in the system.

 

I have used seafoam many times. It would be good for a while. I have filled the carbs with seafoam and then drained the bowls, same thing.

[flyday58]

Try to narrow down which drain tube(s) are dripping to know where to go with it.

 

A little history: have you had the bike long, has it sat up at all? Any info will help.

 

Richard

[Peder_y2k]

It is time to pull the carbs so you can remove the float covers and remove the needle and pull the needle valve seat out and replace the small o-ring that seals it into the carb casting. These tiny o-rings are often overlooked.......... and are notorious for drying and shrinking that permits fuel to leak right past the valve assembly. Not through it, alongside it.

While the carbs are off, replace the original fuel lines with new. As time goes by, the inner wall of the fuel lines begin to crumble and that debris will block the the inlet valve open for sure. Install new fuel hose from the tank thru to the carbs as well as a new fuel filter.

Don't respond with any questions or backtalk, just do it.

-Pete, in Tacoma WA USA

[mralex714]

It is time to pull the carbs so you can remove the float covers and remove the needle and pull the needle valve seat out and replace the small o-ring that seals it into the carb casting. These tiny o-rings are often overlooked.......... and are notorious for drying and shrinking that permits fuel to leak right past the valve assembly. Not through it, alongside it.

Will this o ring be the repair kit?

[cowpuc]

It might not be a bad idea to pull the seat, pop the sending unit out of the fuel tank and have a peek inside the fuel tank too, make sure you got a good clean tank to start with.. It doesnt take much rust to cause real problems for the float needles and seats. Extra fuel filters wont help much with the fine particles if its rust - rusty tanks gotta be dealt with.. If it is rusty, let us know cause there are ways to repair..

[cowpuc]

By the way,, I helped a guy with one doing exactly what yours is doing one time MR. I opened the tank up like I am talking about, looked inside with my flashlight and found a hunk of paper towel half dissolved inside his tank..

[Prairiehammer]

Will this o ring be the repair kit?

 

Yes.

 

But, to remove the float valve seat, one must remove the aluminum plug (Yamaha calls it a "cap") that is staked to the carb body. This plug also has an O-ring, and depending on how you remove this plug, the plug and its O-ring may require replacement as well. The retaining plug part number is 41R-14118-01-00. The part number for retaining plug O-ring is 1FK-14147-00-00.

Edited February 9, 2015 by Prairiehammer

[Vonwolf]

Yes.

 

 

But, to remove the float valve seat, one must remove the aluminum plug (Yamaha calls it a "cap") that is staked to the carb body. This plug also has an O-ring, and depending on how you remove this plug, the plug and its O-ring may require replacement as well. The retaining plug part number is 41R-14118-01-00. The part number for retaining plug O-ring is 1FK-14147-00-00.

 

I have my carbs off now and was trying to figure out how to get these plug's out, it seems like the only way is to destroy them. Does anyone know how to remove these plugs, I'm sure my seats are toast, but I don't want to drill them out as it seems the only way to do it to me

[Prairiehammer]

I have my carbs off now and was trying to figure out how to get these plug's out, it seems like the only way is to destroy them. Does anyone know how to remove these plugs, I'm sure my seats are toast, but I don't want to drill them out as it seems the only way to do it to me

 

The caps may be 'staked' like this:

If so, try to remove or mitigate the protrusions that help to hold the cap in the carb body. Then using a punch, drive the float valve seat out. The valve seat should push the cap out as the seat is driven out. The net filter will be squashed, but the new float valve assembly should include a new one.

Here's how to drive the valve seat out:

[mralex714]

Yes.

[ATTACH=CONFIG]97191[/ATTACH]

 

But, to remove the float valve seat, one must remove the aluminum plug (Yamaha calls it a "cap") that is staked to the carb body. This plug also has an O-ring, and depending on how you remove this plug, the plug and its O-ring may require replacement as well. The retaining plug part number is 41R-14118-01-00. The part number for retaining plug O-ring is 1FK-14147-00-00.

[ATTACH=CONFIG]97192[/ATTACH]

[ATTACH=CONFIG]97193[/ATTACH][ATTACH=CONFIG]97194[/ATTACH][ATTACH=CONFIG]97195[/ATTACH]

 

I have a non OEM kit and it doesn't have a screen. Similar to this one.

 

4X 86 07 VMAX Carb Kits VMX1200 V Max 83 93 XVZ13 Venture Venture Royale | eBay

 

This will fix the overflowing problem. What about the flooding and the fuel pooling on top of the butterfly valves?

Also I have fuel squirting out of the hole to the left or right of the caps when the bike stops running.

Edited February 9, 2015 by mralex714

[mralex714]

By the way,, I helped a guy with one doing exactly what yours is doing one time MR. I opened the tank up like I am talking about, looked inside with my flashlight and found a hunk of paper towel half dissolved inside his tank..

 

Any how to's on removing and servicing the fuel tank?

[Prairiehammer]

I have a non OEM kit and it doesn't have a screen. Similar to this one.

 

4X 86 07 VMAX Carb Kits VMX1200 V Max 83 93 XVZ13 Venture Venture Royale | eBay

 

This will fix the overflowing problem. What about the flooding and the fuel pooling on top of the butterfly valves?

Also I have fuel squirting out of the hole to the left or right of the caps when the bike stops running.

 

On eBay there are a few sellers offering the net filter (PN. 1J7-14994-00-00), albeit the filter is not cheap. I would think you could reshape the deformed screen and reuse it, provided the plastic collar is intact.

 

IF the flooding and pooling is the result of a too high fuel level in the float bowl and IF the too high fuel level is a result of fuel leaking past the float valve seat, then replacing the float valve seat, needle valve and O-ring should fix the flooding. If, however the fuel level is NOT out of spec, then you should investigate some of the other causes for the flooding, ie. jet block rubber plugs shrunken or improperly vented bowl or main nozzle worn into an oval shape. Have you checked the float bowl fuel level?

 

Also I have fuel squirting out of the hole to the left or right of the caps when the bike stops running.

 

I don't know which 'hole' you are referring to.

[cowpuc]

Any how to's on removing and servicing the fuel tank?

 

Sure, but start with removing the sending unit so you can see if the tank is a problem.. Pull the seat (two bolts - one on each side of the seat - on an 83/84, not sure if this applies to the MK2), you will see the sending unit mount plate on top of the tank, disconnect it, pull the bolts and lift it out - carefully so you dont bend up the rod hanging into the tank. You should now have a pretty good window to look into the tank.. Also, I like to stick my finger in and rub across the top of the inside of the tank and see how bad it is - I have a mirror I could use to check this just as easily but I like to get my fingers dirty..

Hopefully its all nice and clean but if its not let us know and we will give you some pointers in pulling the tank for cleaning and resealing if needed..

[cowpuc]

Here ya go MR,, check this link out, Mcgyver has some really pics and info here addressing exactly what I am talking about.. If you thumb thru the posts here you will be shown how to pull the tank but you will also get to see the sending unit and the window into the tank I was talking about..

http://www.venturerider.org/forum/first-generation-venture-tech-talk/84188-bringing-83-street-hopefully.html

[mralex714]

I started it today it ran for about a minute and stalled. I took off the airbox and again gas was pooled on top off 3 of the butterfly valves, there was no gas from the overflow hoses. I'm guessing this has been the cause of my poor gas mileage,30-33 mpg.

[Snaggletooth]

Pulling the tank to clean and use a sealer is a bit of a job. Not hard, just time consuming. I found the easier way was to rather than remove every piece on the rear of the bike was to disconnect all wiring and lines of anything attached to the rear subframe then just remove the connecting bolts where the subframe bolts to the frame itself and remove the entire assembly with everything intact. One man job coming off. Nice to have a second pair of hands lining it back to when it's time to put it back together.

 

As for dealing with the tank now, good idea. That was the root of all my carb problems several years ago. The fine flakes of rust were going all though my fuel system. Had the carbs off several times dealing with overflow nightmares. Ended up not needing the seats but just needles, floats and all fuel lines. The Epoxy tank seal took care of the rust.

 

Been about three years now with no more carb or fuel problems. Worth the effort to check everything and do it all now and be done with it.

[mralex714]

I don't know which 'hole' you are referring to.

 

There are 5 openings on the intake of the carbs. On the left 2 carbs the round opening at the 12 o'clock position and 6 o'clock on the right 2.

[dna9656]

YOU tell'em Peder! BTW my plugge pilot valve hasn't un plugged yet would you be interested in looking ovr myshoulders during a tear down/assembly? I'll buy lunch....

[Peder_y2k]

YOU tell'em Peder! BTW my plugge pilot valve hasn't un plugged yet would you be interested in looking ovr myshoulders during a tear down/assembly? I'll buy lunch....

 

Yeah you can buy me lunch............again. We'll do it on a weekend when we can get together.

 

-Pete

[mralex714]

Started it today I took off the airbox and the 3 carbs that pool gas have fuel running around the needle and collecting on the butterfly valves. Also fuel is coming from, I think it's the main air jet on top of the 3 carbs.

[mralex714]

I finally removed the carbs and looks like tank rust is the root of my problems.