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Discussion Starter #1
Hey all, just rebuilt the carbs. Bike starts right up and idles however, when I goose the throttle it seems like(and does at times) want to die out. If I open and close it quickly a couple times she'll rev high or if I ease it on, but from an idle when I snap it open seems like it just wants to bog down and die. Haven't ridden it yet as its not tagged. Also seems like the rear cylinder isn't firing completely, which is why I rebuilt the carbs in the first place. Has v+h pipes and you can def hear the right exhaust louder than the left until the rpm's get up some.
99 vn750 with 20,000 miles. just bought it a few months back
 

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did you re-jet at all, or just deep clean them?
 

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Discussion Starter #4
Hey guys, thanks for the replys! I've been really busy at work and didn't have any free time to get back. Yep, installed all new jets and no, didn't balance the carbs. In the meantime, I drilled out the air/fuel mixture plugs and adjusted the screws. Much better now and seems fine. Took it for a test ride and won't go over 35-40 mph and 4000 rpm, though it is smooth and even. Thinking this is due to replacing the petcock with an ebay non vac style. Had to tee the carb lines together and I'm thinking it's not flowing enough gas. grr...
 

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It should run with a tee on the lines, as long as the lines aren't running uphill, like with extra long hoses.

Earshaved or not? Where are the carb vents? Wind on the vent hose can make it run out of fuel.
 

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Also sounds like a possible vacuum leak. Had this problem with mine... it was the front boot on the carburetor. I would check by spraying carb cleaner on your boots and if it idles up, its a vacuum leak.
 

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Discussion Starter #7
No ear shave. Carb vent line is running under seat and down, not exposed to any wind. Same place it was before I removed the carbs. Replaced tee with a larger one, still the same. Starts right up, can rev it up sitting there, but when take off down the street it just tops out at 40 mph and about 4000 rpm. Engine runs completely smooth, no sign of bogging like out of gas. Thinking maybe float adjustment? But both being out the same seems unlikely. I could see one which may have one cylinder not running right. I'll double check the boots and the vac port to be sure it's capped off completely. sigh...funny thing is, I have a vtx 1800 and a dyna superglide and I like this better than both.
 

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I won't say for sure it's the problem, but people have had trouble with the vent line run under the seat.

It's always the frame under the gas tank (pointing back), the blank nipple on the gas tank sender cover, or the vent hose spot in one of the ears, that works for sure. I know you said the vent was there before, just saying...

I agree on both floats being too low, big odds there. Though float level is pretty easy to check with carbs on the bike. Just a piece of clear tubing and an allen wrench?

Gas tank vent partially clogged, holding back fuel flow? Try it with the cap unlocked?

Any difference if the petcock is on reserve?
 

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Discussion Starter #9
well the one vent line from the carb to the vac tee was off. Put that on and still the same. Tried reserve and unlocked the gas cap too. What I just noticed is the exhaust on the rear cylinder (left side) is cool, the exhaust from the front cylinder is hot. that can't be good.
 

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You can check the plug on that cylinder, see if it's really dry and has spark. If it's dry, the carb has a stuck float or dirty jets.
 

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Gid'day all,from downunder.Having same problems after mini rebuild.Had ignition problems with green death on coil spikes/plug leads.Rectified them,new slow jets#38.Now runs smooth on start/idle,up to about 4000rpm.Will run up to 6,if throttle opened slowly,but if blipped ,sounds like starving for fuel.Am checking all vacuum lines,boots.Havnt adjusted floats,levels ok.Will remove carbs (again) to check diaphrams??
 
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