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Discussion Starter · #1 ·
Started the old bus up this morning only to find fuel pissing out all over. It was visibly flowing from the airbox, (could have started higher). It does not leak when it is not running. Before I tear the tank off, what do you lot reckon.

It was fine after I put it back together a few weeks ago post valve adjustment. I took it on a 15 mile run with no issues.

Looking forward to your thoughts................
 

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If its coming from the airbox its almost certainly to be a stuck float valve or holed float. If it stops when the bike is off then its very likely to be coming from the airbox / carbs and not from above.
 

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Started the old bus up this morning only to find fuel pissing out all over. It was visibly flowing from the airbox, (could have started higher). It does not leak when it is not running. Before I tear the tank off, what do you lot reckon.

It was fine after I put it back together a few weeks ago post valve adjustment. I took it on a 15 mile run with no issues.

Looking forward to your thoughts................
2.5 thoughts:

I had a float come completely loose once (bad o-ring seal) that caused the fuel in one carb to keep flowing in. Easy fix but the carbs have to come out, which means the plastic has to come off, and the tank has to come off, and the airbox has to come off, and the throttle cable at the grip needs to come off, then the carbs can come out far enough to get the choke cable off, then the bowls removed to see if this is the issue. Reassembly is the reverse of removal. If you had a float come loose it would probably not run perfectly and continue to dribble gas underway.

It is remotely possible that a piece of grit or dirt could hold the float valve stuck open in which case it might just flush itself out and stop doing it for a while until it does it again. Or a rap with something non-marring may close a stuck float valve. Hey, it could happen. It may just buy you enough time to get the parts together to renew the wear items (rubber parts) in the carbs.

If this hasn't been done in forever a simple carb rebuild is pretty easy if you work leisurely and carefully (but possibly intimidating until you've done it once) and will take the majority of a day the first time and count yourself successful if you don't break anything with the amount of stuff that has to be removed to get the carbs out.

If you get to this point consider borrowing a carbtune or something and syncing them (5 min job), maybe renewing the air filter since you're there already.

At least you know your vacuum tap is working.:D
 

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I know the feeling...

Well, if you haven't already, it's time for a carb rebuild.

If I were you I'd give Wayne a call over at MPH. He used to run service for British USA there on the South side. If he's not at MPH, they can direct you.

If you need some part #'s, I'd be glad to share the parts I needed (Mikuni's).

Best wishes.
 

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Well, if you haven't already, it's time for a carb rebuild.

If I were you I'd give Wayne a call over at MPH....
Wiayeman,

+1 on the carb rebuild.

Wayne left MPH a long time ago. I'm not quite sure where he landed, or if he ended up at anything motorcycle related. He sold a few of his bikes (including his Triple) and seemed to drop off the map. Since Ming's closed, I don't see those guys as often as I used to. I usually ride alone these days. Although, I did run into them a few weeks ago out near Navasota. Wayne wasn't with them.

Ashley, at British USA\Gulf Coast, can get you all the Mikuni parts for a complete rebuild.
 

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Ming's?
 

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Discussion Starter · #8 ·
Howay lads, there must be an easy fix including cod liver oil and pigeon feathers. I really don't want to rip it to bits again............
 

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Howay lads, there must be an easy fix including cod liver oil and pigeon feathers. I really don't want to rip it to bits again............

There is, I got it off the internet so it must work;) you need a rubber chicken, a live koala bear and a bottle of HP sauce...

Actually, probably easier to renew the rubber o-rings on the float assembly.
 

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Chinese restaurant where we all used to hang out on Thursday nights. It was a weekly gathering for about 8 years. Owner closed the place and headed to Austin. Still stop in and see him every time I ride through Austin.

http://www.myspace.com/mingsaustin
I was wondering, 'cause there's this guy named Fei here who owns a restaurant called Ming's.... :D

(Wednesdays, though, not Thursdays.)

Cheers,
-Kit
 

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I've heard that sometimes cutting the fuel source and running the carbs dry, then when you turn the fuel back on it'll flush the grit out of the float valve. The challenge of that with a vacuum actuated petcock is cutting off the fuel with it running. I'll leave it to you to figure that out (since I can't remember if there's an easy way to do it other than pulling the vacuum line loose from the petcock).
 

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it would probably be easier to pull the vaccuum line off the carb, and just block the stub off with another pipe, thats plugged at the other end.shouldnt have to lift the tank that way.
 

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I was wondering, 'cause there's this guy named Fei here who owns a restaurant called Ming's.... :D

(Wednesdays, though, not Thursdays.)

Cheers,
-Kit
Same Fei, same good food, better city, ...same mikuni's in need of a rebuild... :D
 

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Is that the line that runs into the top of carb #3?
Not always #3, but it should be the only line running to the top (plastic part) of any carb.

Cheers,
-Kit
 

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Yeesh. :p

True enough, though. The only *factory* line going to the top of the carbs.

Cheers,
-Kit
 

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Discussion Starter · #19 ·
Right, so take off the vacuum line from the top of the carb. Replace that line with another that I have plugged. Run it out of petrol (hopefully without catching on fire first) and then reattach the factory hose and see if the petrol being reintroduced into the now dry carb may flush the ****e out that has it stuck now?????
 

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Right, so take off the vacuum line from the top of the carb. Replace that line with another that I have plugged. Run it out of petrol (hopefully without catching on fire first) and then reattach the factory hose and see if the petrol being reintroduced into the now dry carb may flush the ****e out that has it stuck now?????
If your toolbox has a hemostat or some sort of a tool like that you can just pinch it off and leave it attached.

But if its an o-ring out or something you'll likely just overflow again.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38034
 
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