Bike not going past 80MPH - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 20 (permalink) Old 09-15-2018, 03:06 PM Thread Starter
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Unhappy Bike not going past 80MPH

Hey all, I have just bought a 99 Vulcan 750 that a guy has done some work to the bike. When I bought it I didn't know that it couldn't go past 80. It's sitting at 80 in the firth gear. He rejetted the carbs to give it more power, do you think that would be why it's only able to get to 80? I'm totally lost at why it's like this. Any help would be greatly appreciated! Thanks
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post #2 of 20 (permalink) Old 09-15-2018, 05:58 PM
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Lots'a guys w/ more jetting experience here. I'm running a completely stock system. I've got original airboxes, filters, carbs, jets, exhaust, goat's belly--everything. Mine'll do better than 80, so if getting more power was the goal previous owner fell short! Stock system will pull hard all the way up to red-line. Fourth gear will get you to a higher speed faster!

To get help, you're going to have to say whether you're running stock exhaust, air filters, etc. Have you pulled the carbs? Do you know what size jets you've got? I can't help you with that, but somebody here will know what size you need.

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post #3 of 20 (permalink) Old 09-16-2018, 03:58 AM
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Running out of gear above 80. Bike needs 6th so bad........ itíll do it, but itís wound tighter than a hamster on crank.


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post #4 of 20 (permalink) Old 09-16-2018, 07:56 AM
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Originally Posted by One1 View Post
Running out of gear above 80. Bike needs 6th so bad........ itíll do it, but itís wound tighter than a hamster on crank.
and just beginning to get really happy!

these aint harley's that explode at 5k rpm or less.. they dont really wake up until they get over 5k

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post #5 of 20 (permalink) Old 09-16-2018, 08:31 AM
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If youíre pulling away from a stop light, sure. If youíre on your 30th mile itís waterboarding for the ears.


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post #6 of 20 (permalink) Old 09-16-2018, 10:23 AM
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These bikes can do an honest 110 mph. Sounds like the PO screwed up the bike.
Make sure the carb vent line is placed right, and make sure both cylinders are firing.
Then check what jets are in the bike.

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post #7 of 20 (permalink) Old 09-16-2018, 12:04 PM
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Almost certainly a lack of fuel.

Vent hose placement.

Dirty main jets.

Sticking slide, leaky slide diaphragm, more shims needed on the slide needles.

Restricted flow through the petcock.

Try pulling the choke lever to see if it picks up speed at all. If it does, it's definitely not getting enough fuel.

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Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
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post #8 of 20 (permalink) Old 09-16-2018, 12:22 PM
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YUP, what Spockster said. Mine will do 100 no problem pushing along a Vetter Windjammer, cruises the TurnPike at 80 easily. Yours should do over 100 without overt stress

'99 Vulcan "Victoria"
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post #9 of 20 (permalink) Old 09-16-2018, 01:12 PM
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Something else to check: Make sure the air filters haven't disintegrated and clogged the air intakes/airbox.

Earshaved or not?

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__________________________________________________ ____________
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post #10 of 20 (permalink) Old 09-16-2018, 02:12 PM Thread Starter
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Hey all thanks for the replies. It has shaved ears with k&n air filters. I've checked the vent lines and they are fine. I'm not sure what size jets are in there but I'm thinking of going back to stock if some one could let me know what size they are. I'll also try the choke to see if that helps out any.
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