Kawasaki VN750 Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
Last fall I purchased an1995 750 with about 23000 miles. The owner had recently installed Vance/Hines pipe and it sounds freakin awesome. The only concern is the incessant popping whenever you let off the throttle.

He did not rejet and the local service dept says it needs larger jets to make up for the pipes, nor did he have the carbs adjusted. Just add pipes and go! The Plugs had a white coating, not gray or brownish. I have noticed a lag of power at the top end even though has great low end torque.

What say all of you? Haven even cracked the carbs open so don't know what the stock jets are to order larger sizes.

Bob......
1995 VN 750
KN Air filters
Vance/Hines Pipes.
 

·
The Professor
Joined
·
3,147 Posts
Last fall I purchased an1995 750 with about 23000 miles. The owner had recently installed Vance/Hines pipe and it sounds freakin awesome. The only concern is the incessant popping whenever you let off the throttle.

He did not rejet and the local service dept says it needs larger jets to make up for the pipes, nor did he have the carbs adjusted. Just add pipes and go! The Plugs had a white coating, not gray or brownish. I have noticed a lag of power at the top end even though has great low end torque.

What say all of you? Haven even cracked the carbs open so don't know what the stock jets are to order larger sizes.

Bob......
1995 VN 750
KN Air filters
Vance/Hines Pipes.
V&H with or without baffles? Stock air filter housings? Where do you live? Stock jets are #132 you should be fine with #135 The popping on deccel is due to the reed valves, you need to coaster or marble. :smiley_th
 

·
Premium Member
Joined
·
1,766 Posts
If the bike runs right, no hesitation or bogging and your plugs look like the correct color, don't mess with it.

Jon
 

·
Registered
Joined
·
410 Posts
I always thought the occasional pop sounded cool myself and i am a quiet pipes rider, should see the deer scatter when she pops:rockon:
 

·
"ya can't live forever"
Joined
·
321 Posts
re jet

Yes re-jet.....go to Factory Pro they have a complete kit ready to go. By the way is the bike de-goated and the air box removed? If not you'll want to pull them out also then just hold on you'll be flyin'.
 

·
The Professor
Joined
·
3,147 Posts
Yes re-jet.....go to Factory Pro they have a complete kit ready to go. By the way is the bike de-goated and the air box removed? If not you'll want to pull them out also then just hold on you'll be flyin'.
The Factory Pro jet kit will have jet's that are too large unless you do an earshave. Just buy seperate jets that will work for about $12.00- $15.00 instead if a kit for $70.00 -$100.00. :smiley_th
 

·
Registered
Joined
·
9 Posts
Discussion Starter #8
OK I get the Marble... pretty ingenious... Kinda like what I did with the turbo bell hose on my Buick Grand National..
BUT WTF is deg-goating?
 

·
The Professor
Joined
·
3,147 Posts
OK I get the Marble... pretty ingenious... Kinda like what I did with the turbo bell hose on my Buick Grand National..
BUT WTF is deg-goating?
With the V&H exhaust your scoot has been de-goated. :smiley_th The Goat's Belly is a pre-muffler chamber.
 

·
Premium Member
Joined
·
4,054 Posts
V&H with or without baffles? Stock air filter housings? Where do you live? Stock jets are #132 you should be fine with #135 The popping on deccel is due to the reed valves, you need to coaster or marble. :smiley_th
Lance, I seem to notice some higher rpm lack of performance since I added the V&H's. Baffles in, and no other mods to air system except for K&N replacement air filters. I live in central Texas, altitude between 600 and 1400'. Would the 135 be right for my bike? And where would you order them?
 

·
The Professor
Joined
·
3,147 Posts
Lance, I seem to notice some higher rpm lack of performance since I added the V&H's. Baffles in, and no other mods to air system except for K&N replacement air filters. I live in central Texas, altitude between 600 and 1400'. Would the 135 be right for my bike? And where would you order them?
It depends on how your plugs look, if they are on the whitish side then #135 jets will help a little. The only way to get better top end performance is by getting more air into the carbs. and rejetting.:smiley_th
 

·
Premium Member
Joined
·
4,054 Posts
I finally pulled my plugs and they are white-ish, rear more than front. I mean, the bike still runs good, just a little less responsive after 4500 rpms than it was before the v&h's.
I thought I'd read on here a few years ago that you could change the main jets without removing the carbs. Or was that a dream I had?
 

·
Registered
Joined
·
721 Posts
I finally pulled my plugs and they are white-ish, rear more than front. I mean, the bike still runs good, just a little less responsive after 4500 rpms than it was before the v&h's.
I thought I'd read on here a few years ago that you could change the main jets without removing the carbs. Or was that a dream I had?
you can.. I forget how now.. but it is possible and MUCH easier!
 

·
The Professor
Joined
·
3,147 Posts
I finally pulled my plugs and they are white-ish, rear more than front. I mean, the bike still runs good, just a little less responsive after 4500 rpms than it was before the v&h's.
I thought I'd read on here a few years ago that you could change the main jets without removing the carbs. Or was that a dream I had?
Keihin Main Jets. :smiley_th

http://cgi.ebay.com/ebaymotors/Keihin-99101-393-Main-Jet-Jets-CB750-VB-VD-VE-VFR750R_W0QQcmdZViewItemQQ_trkparmsZ66Q3a2Q7c65Q3a1Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem170287370312QQitemZ170287370312QQptZMotorcyclesQ5fPartsQ5fAccessories
 

·
Registered
Joined
·
748 Posts
Yes re-jet.....go to Factory Pro they have a complete kit ready to go. By the way is the bike de-goated and the air box removed? If not you'll want to pull them out also then just hold on you'll be flyin'.
Nyet; you do not need to rejet when changing exhaust systems on the Vulcans, unless you're going with no baffles at all. No baffles is something I don't particularly recommend, either; a little backpressure keeps the valves from getting burnt, among other things. Unlike some other bikes, Kaws suffer from stifled intakes, not exhausts.

That said, it wouldn't hurt to go the next size up from the stock 132s to 135s; the Vulcans are set a bit lean from the factory. You'll need to adjust the A/F mix screws, either way. Any larger than 135s, I'd go the whole shebang and do the earshave.

Jim
 

·
social_enemy0
Joined
·
13 Posts
i need help with the popping ive hot the v&h without baffles, stock intake for now, marbled, and i live on the texas gulf coast
 

·
Linkmeister Supreme
Joined
·
7,960 Posts
i need help with the popping ive hot the v&h without baffles, stock intake for now, marbled, and i live on the texas gulf coast
You are running lean.
Remove the soft metel covers from over the air/fuel mixture adjustment screws.
Turn them all the way in clockwise until they gently bottom. (probably only 1 to 1 5/8 turns out from the factory).

Then turn them out CCW from 2.5 to 3.5 turns until the popping/backfiring stops when decelerating.
CAUTION - At 5 turns CCW you run out of adjustment threads and the screws fall out.
Lock them in position with a dab of silicone sealant.
 

·
Registered
Joined
·
1 Posts
re-jet after V&H exhaust

My friend has a 88 vulcan 750 that he put V&H exhaust with baffles and stock exhaust. We live in Montana so elevation is around 3000 feet. I haven't seen any kits for the vulcan, what jets should he go to?
 
1 - 20 of 21 Posts
Top