Help! Vacuum hose on petcock

I'd rather stay stock than do the TW mod.... Right now anyway. My attention span and patience isn't real good, and I'd have to cap the vacuum line on the carb, and find a T or Y fitting for dual carbs. I already ordered the kit for the VN petcock anyway. If it doesn't work or fails, I'll probably get a TW petcock. I appreciate the advice though. It would be very nice to get rid of some of the unnecessary crap. Simple is always better, except when my patience is running out.

Hopefully it's not a needle and seat issue. Maybe I should just go through the carbs, just for the heck of it. There's a lot of parts that have to come off to clean those suckers!

Quote:
Originally Posted by AMW View Post
that line has gas that appears to be going to the tank, from the carb.

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wmsonta said:

If that statement is true, you have a needle/seat issue. It absolutely can happen.

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Are you sure wm? Seems like it would have to be a lot of volume (to make pressure) in order to get fuel pushing up the vac line into the tank, which will have X amount of fuel pushing down on it (needing a busted diaphragm to boot). Assuming it could, where would the gas go if the diaphragm isn't compromised?

Then, the fuel has to get out of the bowl, pass through the vac port... wouldn't it just get sucked into the cylinder instead? Because the vac port wouldn't be in the bowl.

All the above has to have a busted diaphragm to be plausible, in which case the fuel normally is pulled by vacuum into the intake, with that malfunction.

Not arguing here, just trying to understand the how of it.

do the petcocks on these bikes have a prime? Then the vacuum line on the petcock wont even be used, just as a test.

kenny

Mercury said:

do the petcocks on these bikes have a prime? Then the vacuum line on the petcock wont even be used, just as a test.

kenny

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Someone correct me if I am incorrect....

I believe the 1985 - 1987 or 1988 VN750's are the only Petcocks with Prime. (Reserve / On / Prime)
EDIT:
The newer VN750 petcocks have Off instead. (Reserve / On / Off)

:smiley_th

If the filter screen is damaged on the reserve side, I would try not to run on reserve at all. No matter how clean the tank is now, something will get in there. Figure out how many miles you can go for a 2 1/2 gal fill-up, probably somewhere around 120? & stick to it until you can get that fixed. If you haven't ear shaved and you don't have to remove the carbs, ya really don't wanna.

I thought prime was only on the first coupla years - regardless, a 2001 stock bike will not have prime.

nopickles98 said:

If the filter screen is damaged on the reserve side, I would try not to run on reserve at all. No matter how clean the tank is now, something will get in there. Figure out how many miles you can go for a 2 1/2 gal fill-up, probably somewhere around 120? & stick to it until you can get that fixed. If you haven't ear shaved and you don't have to remove the carbs, ya really don't wanna.

I thought prime was only on the first coupla years - regardless, a 2001 stock bike will not have prime.

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stock drifters have 'prime'.

so do stock vn800 classics.

just fyi.

Spockster said:

Are you sure wm?

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I am not sure. I am wrong.

edit-thank you, Spock.

The carb fittings can be plugged with simple vacuum caps available at any auto parts store, or you can just leave the hoses on them and stick a screw in the open end.

How does the TW200 petcock mod work? Is it a direct fit? Sounds like something I might want to do. Vacuum petcocks are something I've never liked.

wmsonta said:

I am not sure. I am wrong.

edit-thank you, Spock.

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No problem, wm, thank ya back. I was thinkin' I missed sumpin', which wouldn't be too unusual. lol

Jerry, the TW200 petcock mod should turn up in a search, I know there have been recent posts about it in the past six months.

First post:

AMW said:

I bought a 2001 Vulcan 750, and....

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Mercury said:

stock drifters have 'prime'.

so do stock vn800 classics.

just fyi.

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thought we were talking about the 750 Vulcan - least that was what I was trying to help with.

nopickles98 said:

First post:





thought we were talking about the 750 Vulcan - least that was what I was trying to help with.

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Aye, I thought when you wrote this:

I thought prime was only on the first coupla years - regardless, a 2001 stock bike will not have prime.

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you were talking about all bikes in general.

kenny

Mercury said:

Aye, I thought when you wrote this:

nopickles98 said:

I thought prime was only on the first coupla years - regardless, a 2001 stock bike will not have prime.

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you were talking about all bikes in general.

kenny

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Ha - I don't think I'm qualified to touch a vintage "first coupla years" of "bikes in general". Can definitely see how I coulda been more concise though.

All good bro

Rebuilt my petcock, and now it runs better, but dumps gas out from between the carbs. Ughh!!! I won't let it kick my ass.... Yet. I will take the carbs off, clean them, and see what's going on. Probably should have done that before. Live and learn, right?

AMW, pulling and reinstalling the carbs on these bikes with the black plastic surge tank in place is a pain in the butt. Maybe you just need to check the fuel lines to the carbs first before pulling the carbs. I pulled my carbs (took about an hour of wrestling with them to get them out) and after reading how it's twice as hard to get them back in with the surge tank in place I just went ahead and did an earshave to get rid of that blasted surge tank. Research earshave and carb removal threads before pulling the carbs.

We all need to remove the carbs at some point but it's nice to ride for a season or two before having to deal with it.

Does anyone know where to get the petcock vacuum hose from? Also, there is a long tube, I believe it's a vacuum wire when I take off the seat I see it. The bike didn't run since 1999 my dads said. Does anyone know where it connects to and where i can buy a vacuum hose for our 1989 Kawasaki Vulcan 750

khaisvt said:

Does anyone know where to get the petcock vacuum hose from? Also, there is a long tube, I believe it's a vacuum wire when I take off the seat I see it. The bike didn't run since 1999 my dads said. Does anyone know where it connects to and where i can buy a vacuum hose for our 1989 Kawasaki Vulcan 750

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Any auto parts store should have vacuum hose.

I'd probably have to see the tube, there's the air system, and also a coolant tube.

Fuel lines in the first pic might be too long. Could cause weak fuel flow.

The other two might be coolant overflow and a vacuum line to the air valve under the seat. Have to follow them to the end and see where they're connected.

Spockster said:

Fuel lines in the first pic might be too long. Could cause weak fuel flow.

The other two might be coolant overflow and a vacuum line to the air valve under the seat. Have to follow them to the end and see where they're connected.

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Okay, no clue if that's for coolant, the petcock is the only thing stopping us from starting this bike. Only need to connect that and the gas tank and it should fire up. Let me know if you can find anything online, thanks!