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Discussion Starter · #1 ·
Hello all,

A little backstory, bike is an '02, 22k miles. I have owned it for about 10 months, my first bike. I Did the ear shave a couple of weeks ago and now its not running the same. (Ran like a BOSS before that). It stumbles when I am cruising in 5th and go 1/2 to WOT. That's pretty normal after an ear shave from what I can gather with all the reading on here I have done so far. If I do a long pull through the entire power band in each gear, I am kissing >80 mph before I even get to 5th. So the 'ole girl still has power for days. (and no stumbling when I do this) The carb vent hose is in dead air up in the frame (went with the easy solution first.) I guess I am just wanting confirmation that a rejet is in order? I am new to bikes, but I learn fast. This forum is a god send!
 

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I did an ear shave on my first bike and went with 40/140 jets and no shims on the needles. I was running stock exhaust with mufflers removed and goats belly (crossover chamber) still intact.

As for the vent hose, the best place to put it is on the spare fitting on the underside of the gas tank (not the fitting on the back of the tank). It's hard to know what's truly dead air on this bike!
 

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Discussion Starter · #4 ·
I have k&N filters on there, but I was stupid and ordered the wrong part number. So I have them "shed boy" (jerry rigged) fitted on the original inlet hoses, but just sticking out the side. I have a feeling this is giving me a lean condition in the front cylinder at highway speed, because it's basically acting as a ram air.
 

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What rpm are you at when you start to get the stumble?

Sounds like maybe a bad transition from the pilots to the mains, depending on the rpm where it begins.

Have you checked the plug color?

Might try adding a shim to the slide needles and work up from there.
 

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It's the worst between 4-5k and generally disappears by 6K. I plan on pulling the plugs tonight to look.
Is this while riding, or revving in neutral?

I've had two Vulcan 750s, one stock then no mufflers after crossover (goats belly) and then later ear shaved, and one with Vance and Hines exhaust with stock intake.
Both bikes always had a bit of a stumble between 4k-6k when revving in neutral, but ran fine on the road.
 

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Discussion Starter · #8 ·
Is this while riding, or revving in neutral?

I've had two Vulcan 750s, one stock then no mufflers after crossover (goats belly) and then later ear shaved, and one with Vance and Hines exhaust with stock intake.
Both bikes always had a bit of a stumble between 4k-6k when revving in neutral, but ran fine on the road.
This is while I am riding
 

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Discussion Starter · #9 ·
What rpm are you at when you start to get the stumble?

Sounds like maybe a bad transition from the pilots to the mains, depending on the rpm where it begins.

Have you checked the plug color?

Might try adding a shim to the slide needles and work up from there.
Pulled the plugs. To ME these look OK. But I'm a noob...so....
Liquid Wood Water bottle Glass bottle Insect
 

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Just as a side note, do you run any SeaFoam in your tank very often? My son's bike has K&N filters and I am always telling him to run a little SeaFoam at least once a month when the bike isn't ran a lot. I think that the fuel today gets crappy a little quicker than it used to. I did not used to believe in additives but on the bike I see a real difference. I think the small passages in the carb get gummed up a little more from gas evaporating in the carbs if the bike sits a few days. Over a month or so if the bike starts running a little rough it is the first thing I do before changing anything. Especially if it had been running good before.

When we first did the shave it took a little bit to relocate the vent but it was real obvious when it wasn't right. I have been off my bike for a while and am getting things around to do a ear shave on it and I know the carbs are going to be gummy because it hasn't been ran in over a month and the gas is not getting ant better just sitting in the garage. We bought a kit to do my son's jets if needed but never needed them. We are close to sea level and I really thought the lower altitude would have made our gas situation run a little rich if anything.
 
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