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Thread: When is a 750 a 1500? (Winter Project) Reply to Thread
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  Topic Review (Newest First)
02-19-2015 09:08 PM
denny6006 Looks like you're getting there, I take it you resolved the fuel issue? I've always found it kinda odd how much the 1500A looked like the 750. Good luck, it won't be long now

02-19-2015 01:08 PM
GloryRider Almost ready to ride!

I've been working hard on this thing, and I'm almost ready to get it on the road... Had to rebuild the forks, seals were completely dry rotted and disintegrated, and forks were half-full of rusty, nasty old oil and water...

I also replaced both tires, mounted and balanced them myself, which was a new experience, but lots of lessons learned!

I got the front end put back together a couple nights ago, so only have the rear to finish up... I'm going to lube the splines while I have the rear wheel off, and then should be good to go!

Here's some pics

02-03-2015 10:44 AM
GloryRider Dang this fuel system is giving me nightmares!

I replaced the float needles and cleaned everything out real good... put it all back together, and... it's still dumping gas out of the carb breather tube!!

I figured maybe the fuel pump's pressure check valve might be stuck, and it's just continuing to pump, even after the fuel pressure at the carb inlet is too high, thus overwhelming the float needles and forcing too much gas into the float chamber...

To test, I bypassed the fuel pump, and propped the gas tank up on a ladder to gravity feed directly into the carb... the bike started up, and ran fine, without dumping fuel.

Sooo... I guess it's a fuel pump issue... I tried running the pump dry on input and putting my thumb over the output hose to see if it continued to build pressure, but I can't really tell... I guess I'd need a gauge of some sort to really test it...
01-26-2015 04:02 PM
OleDirtyDoc Wow.that makes sense
01-26-2015 11:13 AM
GloryRider In case anyone is interested, lol...

I figured out what happened... it was a stuck float needle!

I took the carbs back off, and separated them, checked the float needles, and one side was stuck, so it wouldn't close, and that caused the pressure in the system to never rise and shut off the gas pump, so the pump just kept on supplying gas, and it kept filling up the carb, and then overflowing out into every place it could!

Anyways... good to know what it was at least!

Hopefully I can get a new one, and remember how to put this carb back together, lol!
01-23-2015 11:44 AM
GloryRider Okay, this is messed up!!

I was working on the bike last night, and hooking things back up... I connected the breather and vac tubes to the surge tank (air box) just like on the VN750... haven't put the ears back on yet since I'm waiting on new Ermgo filters to arrive... I thought I'd just crank the engine to make sure everything was still running okay, and when I cranked it (it was hard to start), all of a sudden fuel started pouring out the bottom of the bike!!

I shut it off immediately, and tried to find the source of fuel leak... everything was dry around the fuel tank, fuel tank vent, petcock, fuel pump, fuel lines, and carb... it seemed that the fuel was coming from somewhere midway up between the rear cylinder and the battery box... the only thing there that could even remotely connect to fuel system is the emissions control vacuum valve canister thingie... It was wet with fuel on the outside, and fuel was dripping down and off the bottom of the frame and engine/goats belly...

The only thing I did differently than the other day was connect the two tubes to the front of the airbox behind where the ears mount... The left one is the crankcase breather, so that can't be the culprit, and the other is a vac line going to the carb I think...

I've checked the manual, and as far as I can tell all the hoses are connected correctly on the carb, and everything is where it's supposed to be...

What in the world could cause fuel to pour out of the emissions vacuum canister!?

I don't totally understand the vacuum system, if one of the ports off the surge tank is blocked, could that cause a vacuum loop, and make the emissions vac suck gas out of the carb??
01-20-2015 03:56 PM
OleDirtyDoc Sweet.sounds good
01-20-2015 12:35 PM
emtdon that's awesome good job. hope it gives you many miles of trouble free rides. love to see bikes brought back to life. good thing is since you have fixed the problems yourself you will know the bike better. good looking bike.
01-20-2015 11:43 AM
GloryRider Resurrected!!

After fixing a bunch of electrical issues, replacing fuel and vacuum lines, repairing the fuel pump, and cleaning/syncing/repairing the carbs, it finally started!!

I took it out for a quick test ride to make sure it'd shift through the gears before I changed the oil, and it runs strong!

I still have to get the brakes working, and calibrate the clutch, and put some new tires on it, and figure out how to mount the seat I got (not a direct fit), but it's almost ready to ride!!

Here's a video of it starting up

01-09-2015 10:27 AM
Originally Posted by GloryRider View Post
Well since a few of y'all are online, not talking about motorcycle stuff... wanna help me figure something out?

I'm still working to get this Vulcan 88 started... I figured out a bunch of electrical stuff that was broken, and now the thing will crank over, and I have spark - yay!

Problem is the fuel pump isn't working... why there's a fuel pump on a carb'ed bike, I don't know, but there is, and it's not working... as far as I can tell, it has power (tested with meter), but it won't turn on, so no fuel is flowing to the carbs...

Anyone know how to bench test or repair this pump? The OEM replacement is insanely priced... $200-$300!!

Maybe there's an aftermarket cheaper one that'll fit?


I don't have an answer to the why they have a fuel pump either. Some of the Honda Shadows do as well. you may be able to replace it with an aftermarket automotive electric fuel pump from Summit Racing or Jegs maybe even a local parts store, or you could get a piece of fuel hose and run it directly from the petcock and try thst for test purposes and see if it actually fires up.

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