[Ritthjp]

I posted over @ VROC but I figure I would post here too.

I have an '86 VN-750. Just a brief history: I have had the engine out, it has been completely de-EPAed, de-eared, etc.

Late last year I started running into a problem. While the bike was shut off, gas would leak out of the right-side air-filter (remember, my airfilters are attached to the carbs.) Reading up on this stuff, I ran across that the petcock controls the fuel - even though there is no "off switch." So, I bought a rebuild kit for the fuel petcock. While in the process, I figured, why not buy a set of good used carbs. So, I bought a set of carbs that were in really good condition. Got the bike back up and running this weekend, rode around for 5 minutes or so, and I ran into the same problem. When I shut it off, I came back a couple minutes later and noticed gas coming out of the right side carb. (This is the carbs I replaced the originals with. I think they came off of a 95 vulcan.)

In the mean-time, I'm installing fuel shutoff valves to shut the flow of gas off while the bike is not running.

However, my fear is that after riding say 15-20 minutes, the flow of gas into the carbs will outweight the usage of gas, and the carbs will flood, and start pouring out of the airfilter, or down in the crankcase.

I have not checked my float level, but for the life of me can't justify it when it has happened on both sets of carb. I've rebuilt the fuel-petcock.

Anyone have any other ideas?

Thanks!
Jason

 

[jm1515]

I posted over @ VROC but I figure I would post here too.

I have an '86 VN-750. Just a brief history: I have had the engine out, it has been completely de-EPAed, de-eared, etc.

Late last year I started running into a problem. While the bike was shut off, gas would leak out of the right-side air-filter (remember, my airfilters are attached to the carbs.) Reading up on this stuff, I ran across that the petcock controls the fuel - even though there is no "off switch." So, I bought a rebuild kit for the fuel petcock. While in the process, I figured, why not buy a set of good used carbs. So, I bought a set of carbs that were in really good condition. Got the bike back up and running this weekend, rode around for 5 minutes or so, and I ran into the same problem. When I shut it off, I came back a couple minutes later and noticed gas coming out of the right side carb. (This is the carbs I replaced the originals with. I think they came off of a 95 vulcan.)

In the mean-time, I'm installing fuel shutoff valves to shut the flow of gas off while the bike is not running.

However, my fear is that after riding say 15-20 minutes, the flow of gas into the carbs will outweight the usage of gas, and the carbs will flood, and start pouring out of the airfilter, or down in the crankcase.

I have not checked my float level, but for the life of me can't justify it when it has happened on both sets of carb. I've rebuilt the fuel-petcock.

Anyone have any other ideas?

Thanks!
Jason

Jason...Welcome to the club!
This is a wild shot in the dark, as I have not done the ear shave or heard of this problem on any of the Vulcan forums...
The hose that used to be in the right airbox that came from the carb..
This is the carb vent hose and supplies ambient air pressure to the carbs...to control the floats, IIRC.
Just recently, it has been discussed that this should not be vented out in the open so as to deliver 'dynamic' varying airflow..it will royally mess up your carbs. I guess it needs to be carefully run along the gas tank somehow.
Check this out....