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Hi,

I am new to this group. I am also a member and owner of a vn750. I just purchased a 1998 Vulcan Classic. I believe it may need a jet kit as it pops through the carb at low throttle. There is also another problem; when I shift into 2nd and 3rd gear, it jumps out of gear. Has anyone had this or the popping happen before? The bike only has 8,00 miles on it. Oh yes I believe it has cobra drag pipes on it.

Nate
 

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I miss you, Deron
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Welcome to the site, Nate. I can't offer any help with your problems, but this is a great place to ask for advice. Lots of great, helpful people here. Congrats on the Vulcan. They're great bikes. I'm madly in love with mine.

Julie
 

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the "fun" guy
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Hi Nate and Welcome! :)

Not sure about the shifting problem....Taking a guess....maybe the clutch needs adjusting?

Has the bike sat for any length of time? If so it's possible that the carb has gummed up and needs a good cleaning. If your not familiar with SeaFoam you might want to buy a can of it and start using it in your fuel. Add 1 ounce per gallon and see if you notice any decrease in the popping through the carb. It's an easy way to begin without having to dig deep right off the bat. You can buy SeaFoam at Napa Auto Parts stores...or most any autoparts stores where you live.

http://www.gadgetjq.com/faq.htm#Exhaust

Others will be along with excellent advise. :)
 

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Official BTK Forum Pot Stirrer
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welcome, glad to have ya
 

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koweena said:
Hi,

I am new to this group. I am also a member and owner of a vn750. I just purchased a 1998 Vulcan Classic. I believe it may need a jet kit as it pops through the carb at low throttle. There is also another problem; when I shift into 2nd and 3rd gear, it jumps out of gear. Has anyone had this or the popping happen before? The bike only has 8,00 miles on it. Oh yes I believe it has cobra drag pipes on it.

Nate
If it has Cobra pipes, it will say Cobra on them and the carb will need re-jetted. If it takes a long time to warm up and has a flat spot when cracking the throttle, it needs re-jetted.
 

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If you're confident that it is indeed backfiring into the carbs, I would synchronize the carbs before resorting to rejetting. Myths have become so common about rejetting that it reputedly cures everything from flat-tires to burnt-out headlight bulbs.
My Superhawk (liquid-cooled V-twin sportbike by Honda) used to backfire in the carbs at idle (and freqeuently die just as the stoplight turned green), but when I figured out how to re-synchronize the carburetors, it stopped happening altogether.

Now the shifting: loosen the adjuster barrel so that the clutch engages in the latter degrees of lever-release. Example: When you pull in the clutch and put it in gear, you should be able to let your clutch out partially before it engages and tries to propel you and the bike forward. This is called the friction zone and by adjusting the clutch cable tension, you can shift this friction zone into the earlier degrees (when the clutch lever first leaves the bar) or the later degrees (when your hand is off the clutch lever completely). You want to have it closer to the later degrees of travel, but not too far out.
Next, you want to make smooth, decisive shifts. Not gradual/soft, but also not stomping the gearshift pedal.

Good luck, let us know how it goes and many happy and safe miles to you in '05.
-Calamari Chris in Carlsbad, CA

P.S. And one thing that dyno-tuners won't tell you about jet-kits is that they usually just over-richen your mix, causing shorter sparkplug life due to repeated fouling, and shorter valve seat life due to carbon build-up. Sure you're backfiring may be cured when they get done with it, but it was probably the fact that they also synchronized your carbs when they were done, not the jet ket.
 

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P.S. You want to loosen the adjuster-barrel (which should be visible to the immediate left of the circled portion in this photo) so that the gap between the clutch lever and housing is about the thickness of a nickel with your hand resting lightly on the lever.


-CCinC
 
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