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Discussion Starter #1
Two months ago, I purchased a '92 VN750 with a little over 7,000 miles on it from a friend. I replaced tires, fluids, foam air filters, etc. and the bike ran great. A ride on a cool Saturday morning was wonderful - engine seemed to run perfectly.

Sunday afternoon ride was different. Bike idles (usually) at just a little over the 1,000 RPM mark on the tach. I had ridden about 6 miles, came to a stop and noticed engine seemed rough. After another 10 miles, I came to a stop and engine was running rough and idle had dropped to less than half the distance between the 1,000 RPM mark and 0 (closer to 0) - and I could smell gas. I headed home. As long as I was running at least 55 mph in 5th gear, I kept moving, but any time I had to slow down or stop, I had to open the throttle to keep the engine up to 1,000 RPM.

Got home and let bike sit while still running. Idle was close to 0 on tach, then died. I could restart, but idle remained low. Started looking around and found that vent hose that runs from carbs to right air filter housing had small amount of liquid (presumed gas although smell wasn't strong) dripping out (just a drop or two). Haven't restarted since. Also noticed that circlips that (I think) hold throttle butterfly in place on right-side carb were damp, assumed it was gas.

Of course I am looking for suggestions as to the problem and a fix.

Thanks.....
 

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i'm not expert on this but it sounds like one of the cilinders flooding due to clogged float valve not closing (anyone please correct me). i would try to put some seafoam in the tank before anything else.

lets wait on expert opinion
 

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"ya can't live forever"
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Check for clogged air filters.....check plugs if black and sooty ....af/s are clogged or idle is too rich.
 

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Once Banned
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Does sound like crud in the carbs. Do like Tankist says. Put 3 oz Seafoam to a tank of gas. Also, check your oil level to make sure the flooding didn't get into the crankcase.

Before running the bike again, drain what is in each carb into a small container. See if one drains more than the other (stuck float), and see how the gas looks - any crud. Try to start the bike - you may have to crank it for a short time to release fuel back into the carbs.
 

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Geek
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Ditto on the...ah forget it.
 

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Discussion Starter #8
Thanks to everyone for the advice. Here's what I tried:

I drained both carbs. The drained fuel looked okay. Then I shot Gumout carb cleaner through the drain hole until it came out the vent hose (sort of reminded me of what happens when you drink milk and laugh). I added the Seafoam to the tank (I would add Seafoam to the tires if I thought it would help) and cranked it until it started. I rode about 17 miles last night and idle seemed to be where it should be. Engine still seemed to run a little rough, but the idle was just a tick over 1,000 RPM on the tach. Will it continue to run? I guess I will just have to continue to ride and see. I do think I will probably have to take the carbs apart and check the floats since I think that is where the problem really lies. Let the good times roll!
 

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TechMech said:
Thanks to everyone for the advice. Here's what I tried:

I drained both carbs. The drained fuel looked okay. Then I shot Gumout carb cleaner through the drain hole until it came out the vent hose (sort of reminded me of what happens when you drink milk and laugh). I added the Seafoam to the tank (I would add Seafoam to the tires if I thought it would help) and cranked it until it started. I rode about 17 miles last night and idle seemed to be where it should be. Engine still seemed to run a little rough, but the idle was just a tick over 1,000 RPM on the tach. Will it continue to run? I guess I will just have to continue to ride and see. I do think I will probably have to take the carbs apart and check the floats since I think that is where the problem really lies. Let the good times roll!
let's say it like this - i read a lot of miracle stories here and some other MC forums. my carbs are fine (PO claims they were cleaned and adjusted this spring) but i still use it every other or 2 fillups and the bike is still in one piece and runs great. ohhh... and this stuff revived my lawnmower. sounds like it was a part of a solution for you too.
another miracle storie about dodging carb rebuild perhaps?
 

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since taking the advice of the people here and adding seafoam to my bike...I actually notice the difference if I do not put it in....I love the stuff
 

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and the Adventure Cycle
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OK, you folks talked me into finally doing the Seafoam.
I haven't had any real problems yet that seemed to be dirty tank/carb related. But this weekend (Thurs - Monday, I took a few daze off work :smiley_th ) I'm going to pick up some Seafoam & give the 'ol Vulcan a shot. :beerchug:
 

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Now what
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*Got home and let bike sit while still running. Idle was close to 0 on tach, then died. I could restart, but idle remained low. Started looking around and found that vent hose that runs from carbs to right air filter housing had small amount of liquid (presumed gas although smell wasn't strong) dripping out (just a drop or two). Haven't restarted since. Also noticed that circlips that (I think) hold throttle butterfly in place on right-side carb were damp, assumed it was gas.

Of course I am looking for suggestions as to the problem and a fix.

Thanks.....*

Try this: Get the bike running and turn the petcock to OFF. Run it until it dies and turn the gas back on. Wait for the bowls to refill, start her up and repeat. Do it a couple of times. This helps the needles clear accumulated crud. No cost effort that actually works sometimes.
 

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and the Adventure Cycle
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Ironman said:
Try this: Get the bike running and turn the petcock to OFF. Run it until it dies and turn the gas back on. Wait for the bowls to refill, start her up and repeat. Do it a couple of times. This helps the needles clear accumulated crud. No cost effort that actually works sometimes.
The way I heard to do this was while you are riding the bike (on an open, little used road, for saftey reasons)
 

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Discussion Starter #14
Thanks for the suggestion. Since using the Gumout through each carb drain hole, the problem has not recurred. I still suspect a float and / or float valve that was stuck in a position that allowed fuel to continue to flow. I will also try letting the fuel run out of the carbs as you suggested. In my subdivision, I just happen to know how far I can get with the fuel petcock in the "OFF" position. I'm sure you can guess how I found this out.

I do have a Seafoam related question. I have used and continue to use Seafoam based on the recommendations in these forums. But I have also noticed that there seems to be some differences as to what Seafoam is or does. Is it a cleaner? I have seen some statements that it is a fuel conditioner - whatever that means. So, friends, what is it really and what does it actually do?
 

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hyperbuzzin said:
The way I heard to do this was while you are riding the bike (on an open, little used road, for saftey reasons)
Sorry-I did mean ride it until it died, etc. etc. etc. And some place where running out of gas wouldn't be dangerous.
 

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TechMech said:
I do have a Seafoam related question. I have used and continue to use Seafoam based on the recommendations in these forums. But I have also noticed that there seems to be some differences as to what Seafoam is or does. Is it a cleaner? I have seen some statements that it is a fuel conditioner - whatever that means. So, friends, what is it really and what does it actually do?
It's a powerful organic solvent. But it doesn't dissolve nylon, which is good since that's what the small socks on the pickup tubes in the gas tank are made out of. I don't know what a "fuel conditioner" is either. Some kind of coach or trainer for gas I suppose. Anyway, Seafoam dissolves normally insoluble deposits so they can be burned away in the engine.
 

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TechMech said:
I do have a Seafoam related question. I have used and continue to use Seafoam based on the recommendations in these forums. But I have also noticed that there seems to be some differences as to what Seafoam is or does. Is it a cleaner? I have seen some statements that it is a fuel conditioner - whatever that means. So, friends, what is it really and what does it actually do?

It is a lot like the MF battery thing... we don't know how it works, just that it does.... It's Magic! :pepper:
 

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Ironman said:
Sorry-I did mean ride it until it died,
I kinda figured that's what ya meant, just wanted to clarify :smiley_th
 
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