So frustrated, 3rd float set, still flooding out needle

[Razorback]

What am I missing?

I went through my carbs, complete disassembly and clean.

I set the float levels initially by gravity feeding the carbs on my bench and checking/setting fuel level with a clear tube on the bowl drain hose.

 

I went to crank it, expecting great results because I felt very thorough.

 

I had #1 & #4 flowing fuel around the needle with the key on. I figure float needle stuck open for some reason although they didn't exhibit this behavior in the bench.

I figured maybe the fuel pressure made it behave differently, so I pulled them off and apart and went through the process again, but this time I took each carb to the bike and fill the bowl hooked directly to the bike with the key on.

I did them all this way, reassembled and turned on the key. Now I have 3 flooding out through the needle jet and down the throat of the carb.

 

Suggestions? I'm not intimidated by pulling the carbs, I've done it about 4 times in as many weeks and twice today.

[MiCarl]

I've only seen two things cause this type of behavior:

 

1) The float needles are marginal so they seal sometimes, not others.

 

2) The twisting and turning to get the rack assembled and installed causes floats to get stuck in an unnatural position. You can tap the float bowls with the handle of a screwdriver while they fill, which is difficult to do on a Venture. You can also fill them until they start to flood then disconnect the fuel pump. Start the motorcycle and let it run for a few minutes before reconnecting the fuel pump. The engine vibration coupled with the falling fuel level often will shake them loose.

[eusa1]

bad o-rings around the brass base of the needle seats will cause this!!

[Razorback]

bad o-rings around the brass base of the needle seats will cause this!!

 

I believe they are all new from my kits it put in in the fall. Does mean they aren't bad, but shouldn't.

[Razorback]

I've only seen two things cause this type of behavior: 1) The float needles are marginal so they seal sometimes' date=' not others. 2) The twisting and turning to get the rack assembled and installed causes floats to get stuck in an unnatural position. You can tap the float bowls with the handle of a screwdriver while they fill, which is difficult to do on a Venture. You can also fill them until they start to flood then disconnect the fuel pump. Start the motorcycle and let it run for a few minutes before reconnecting the fuel pump. The engine vibration coupled with the falling fuel level often will shake them loose.[/quote']

 

Needles are all new, so #2 seems plausible.

I certainly flip them around in every direction during reassembly.

I think I can reach the float bowls with a long screwdriver or dowel.

I'll try that before pulling them yet again.

 

Thanks

[Razorback]

I believe they are all new from my kits it put in in the fall. Does mean they aren't bad' date=' but shouldn't.[/quote']

 

*doesn't mean they aren't bad*

[Money Venture]

Is it possible the floats are hanging up on the bowl gaskets? I have seen this before on another application where everything was great until the bowls were installed.

[Razorback]

Is it possible the floats are hanging up on the bowl gaskets? I have seen this before on another application where everything was great until the bowls were installed.

 

Bowl cover uses O-rings, so I don't see that as a possibility.

[Prairiehammer]

Is it possible the floats are hanging up on the bowl gaskets? I have seen this before on another application where everything was great until the bowls were installed.

 

Not an issue for these carbs. The float bowl 'gasket' is an O-ring style (cylindrical crossection rubber) that is fitted into a mating groove in the float bowl cover.

 

EDIT: I posted this without refreshing the thread, only to see Razorback had already responded.

[bkuhr]

I set the float levels initially by gravity feeding the carbs on my bench and checking/setting fuel level with a clear tube on the bowl drain hose.

Did you ensure you set fuel levels when the carbs were exactly level?

[Razorback]

Did you ensure you set fuel levels when the carbs were exactly level?

Sure did, I set a box next to my bike at approximately the same height as when the carbs are mounted, laid a 24" carpenter level across the top of the carbs (in 2 different directions) and shimmed the box until the carb was level. Then hooked the fuel line from the pump, turned on the key a couple times to make sure the bowl was full and checked and set levels.

 

Edit: at least on the 2nd and 3rd times.

[Razorback]

I banged on all 4 float bowls with a long dowel, turned on the key and have 3 of 4 pumping gas out the pilot air jet. I'll bang on them again and if no success, I'll pull them off for the 3rd time this weekend. I just don't know what I'll do after I get them off this time.

[bkuhr]

Where is your float level set to?

Mine is set here-about in line with choke shaft

[jasonm.]

the proper way to check they are LEVEL is a SMALL level right on the carb itself. NOT a carpenter 2' level. I have a 4 inch level and I set on each individually. Remember we are talking millimeters here. This is a critical thing. Lastly are the floats new ? And are you using the PROPER mark in the carbs for your measurements? DO NOT use the mark on the float bowl. Are you following the YAMAHA service manual ? I think you are doing something improper...or different than what is described in the service manual. Use the marks on the body of the carb below the diaphragm cap. And set 16mm below that. FYI...if you have new floats...set fuel @17mm because over time they will sink due to ethanol. Do this all on a bench ...put the carbs in pairs in a "soft vise". I had issues and they were solved by getting new floats. But what you describe is more than just a bad float or 2.

[Razorback]

Figured it out guys.

 

After reading the shotgun method of carb cleaning (on the bike) I figured why the heck, I'll blow some compressed air through the main jet air bleed, which is where my overflow was coming from, not the pilot air #1 as I had previously mentioned.

When I blew air into carb #3 main air bleed, I got fuel blowing out the main air bleed of the other 3 carbs. I scratched my head and said something doesn't seem right about that.

I wondered why the pressure would be seen in all 3 carbs at the same time when they only share a common fuel source.

For whatever reason, I remembered a thread where a guy had a clogged carb vent/overflow hose causing him problems.

I pulled all of mine and they were all plugged.

My bike has been down about 5 years. I only recently got back to working on it last fall, and my setback after goin through the carbs was I had one overflowing through the main air bleed.

To think I missed a Meet and Eat and all fall riding weather due to clogged vent hoses.

 

I blew them out, put them back on and no more overflowing of carbs. Weird, but I do recall that carb operation depends on some proper atmospheric pressure....somewhere

 

Alas, I still have to pull them again to reset #3 & 4 fuel levels, but it cranked and sounded so good that I really don't mind. I can see the light at the end of the tunnel now.

[Razorback]

Where is your float level set to? Mine is set here-about in line with choke shaft

 

2 are where yours are, 2 others need tweaked.

[Razorback]

I now understand why everything seemed ok with adjustments made off the bike, but back on the bike with all hoses on and I had problems with overflowing.

I was running my bike and checking levels a minute ago and confirmed I have 2 to tweak again.

[Razorback]

Took it down the street for the 1st time in about 5 years. What a feeling, although I didn't get out of 2nd gear.

I had lost my passion to ride, had an economical commuter car and just let the bike sit.

Now I'm back in business now that the kids are old enough to stay by themselves while I take their momma out on a ride in the near future.

 

I just have about 20 minor tweaks to do while finishing up.