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Discussion Starter #1 (Edited)
91 Vn750. I had the engine out for a year. Changed the stator and stator rotor so took the engine cover off completely. Put everything back together. I have 1 year old iridium plugs and new gas. Cleaned the air filters and carb. It just turns over and over and over. No back firing, only one small hick up when spraying starting fluid into the plug ports and/or carb intake. Plugs have gas on them, sparkplugs spark. Battery does not hold a charge but i have jumper cables or boost box on the battery. I have also rejetted it up 2 sizes on each. Also degoated and put after market exhaust on.... but that shouldnt be the issue right?

Not sure what else to try.. any help would be appreciated.

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Discussion Starter #2
Also with the bike on the kick stand, the bike tilted, gas is coming out of the tail pipe. Im starting to think the timing is off. The balance gear was rotated when the fly wheel, rotor, was off but the marks were lined back up.

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Sounds like a stuck float with the gas running out the pipes.
 

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FREEBIRDS MC CENTRAL NY
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try Wolfie's blowback method

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Discussion Starter #7 (Edited)
Sounds like a stuck float with the gas running out the pipes.
I think Im off 180 degrees. I have air and fuel blowing back through the carb so i think my intake valves are still open when compressing. Plus if I had a stuck float wouldnt it still back fire at least the other cylinder would fire? What are the odds that both my floats were stuck especially since I cleaned the carbs before putting the engine back on the frame.

So how do I check the timing? Theres the balance gear and the fly wheel (roter). They were the only things that moved when the engine was out so what could have gone wrong?


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Floats tend to stick most right after the carb has been dry.

Did you have the cams out or the timing chains off? Anything to do with the valve timing or mixing the cams up?

A compression test would show if it's compressing with intake valves open. You just get a low reading, if any. An air test would define it without a doubt, similar to a leakdown test, just without gauge readings.

You really can't alter the ignition timing any, not without re-engineering the pickup coils or the electronics. But ignition timing wouldn't send air back out the intake.

Intake valve stuck open is a possibility, but a huge stroke of bad luck to have it on two cylinders. All the exhaust mixes inside the goat belly, so just checking tailpipes isn't a good indicator of which cylinder has the problem.

With gas pouring out of the pipes, I doubt it could backfire on the flooded cylinder. Not saying it can't, but it's a lot less likely, and I'd want a fire extinguisher close just in case.

Mine would always start up on one cylinder, the idle was down by almost half when it did.
 

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Also with the bike on the kick stand, the bike tilted, gas is coming out of the tail pipe. Im starting to think the timing is off. The balance gear was rotated when the fly wheel, rotor, was off but the marks were lined back up.

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If that's all, your timing is still fine, both ignition and valve timing.

If the marks were off on the balance gear, it would just shake violently, but still start and run.

The rotor is the part that determines ignition timing, and it only goes on one way. The valve timing can't change without removing the timing chains.
 

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Discussion Starter #10 (Edited)
I did not touch anything but the fly wheel (stator rotor). The balance rotated when I took it off but i just rotated it back to line up the marks.

I know the valves are extremely dirty. I might change them now since the bike isnt running.

The pulser coils, i think they are called, are the 2 magnets by the stator correct? I bought used ones, could that be an issue?

How would I get the floats unstuck? I have never had a float stuck in any of my bikes after a carb clean before?

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Discussion Starter #11 (Edited)
When i said air out the intake it only happens occasionally. It has a slight hicccup. But other wise just continuously turns over and over and over and it does push air and the smell of gas out the exhaust.

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FREEBIRDS MC CENTRAL NY
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Which is?

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it's a stickie in the carb section. basically, ya drain the carb,put a hose on the drain,and blow.

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For bike carbs, I smack the sides of the bowl with a plastic screwdriver handle, trying to shake the float valve loose.

Maybe you meant to say plugs are dirty, not valves? Valves aren't easily changed.

Check for spark on the plug wires, that will tell you if the pickup/pulser coils are working.
 

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Try taping on the body of the carbs with a rubber hammer, or a block of wood GENTLY, it may jolt the needle and stop the flow of gas.
 

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Discussion Starter #15
For bike carbs, I smack the sides of the bowl with a plastic screwdriver handle, trying to shake the float valve loose.

Maybe you meant to say plugs are dirty, not valves? Valves aren't easily changed.

Check for spark on the plug wires, that will tell you if the pickup/pulser coils are working.
I meant the valves, they are pretty dirty. Just thought since I had the engine out again. But maybe I should get it running first. The plugs are almost brand new and they have spark when I ground them to the frame.

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Discussion Starter #16
Try taping on the body of the carbs with a rubber hammer, or a block of wood GENTLY, it may jolt the needle and stop the flow of gas.
Tapped the carb and nothing. Tested the compression and it checks out. Still wont start. Im completely clueless.

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If You got gas coming out the tail pipe, and you have spark, pull and check the carbs again? The jets may be to big, but not sure.X3 it's carb related.
 

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FREEBIRDS MC CENTRAL NY
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I'm thinking float sticking or out of adjustment

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Agree with the previous two posts. Just have to bite the bullet and take the carbs out, see what's up with the float. Could be dirt, chunk of rubber from a fuel line, float misaligned ... anything like that can stick the float valve open. It's probably going to be really simple, but will take eyes-on to fix it.

I'm always careful pushing fuel lines back on, have had to remove too many rubber chunks from carbs that were flooding.
 

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Well a real easy test would be to pull the carbs and shoot starter fluid into the intakes. The engine WILL start without carbs, all engines will. If it starts on just starter fluid with the carbs out then you know what the problem is. If it doesn’t something isn’t right.
 
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