Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums

Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums (https://www.vn750.com/forum/)
-   Carbs and Fuel System (https://www.vn750.com/forum/22-carbs-fuel-system/)
-   -   help please!!custom straight pipes (https://www.vn750.com/forum/22-carbs-fuel-system/13014-help-please-custom-straight-pipes.html)

letitflight 10-16-2009 08:53 PM

help please!!custom straight pipes
 
Howdy !

i need some help ! i just made some custom straight pipes 2" and wrapped them with some exhaust wrap. i used the original header pipes and added 2" tube. the 'connexion' between both pipes is tight..no air leaks.
BUT, now the bike is not running right, it seems to hesitate while going up on RPMs. It iddles just fine.
Any ideas?? do you think i will have to rejet this puppy?? (i hope not)

also:
carb is CLEAN
no 'kink' with the fuel lines
new air cleaners (K&N)
Seafoam'ed
air/fuel screw is at 3 turn, i have also tried various settings from 2 turns to 3 1/2 = on difference.
sparkplugs seems to be fine (normal coloring)
battery is good

Thanks in advance!!!:beerchug:

STUMPYSKAW 10-16-2009 09:04 PM

One simple test is when you're excelarrating and the bike starts to hesitate try useing the choke just a little bit, this will richen the air fuel ratio.
Got any pics of the pipes?

dirtrack650 10-16-2009 10:55 PM

K&N's and Pipes? you bet you need to rejet. I'd go 142's on the mains, maybe higher. Your engine will run so much smoother and the power will be restored, even more than stock.

DT

lance328 10-16-2009 11:05 PM

Quote:

Originally Posted by dirtrack650 (Post 118385)
K&N's and Pipes? you bet you need to rejet. I'd go 142's on the mains, maybe higher. Your engine will run so much smoother and the power will be restored, even more than stock.

DT

I just got off the phone with him, he did K&N replacement filters not an ear shave. He's basicaly stock with open exhaust. I told him a couple of things to try, and that he might need to baffle or go with #40 pilot jets and #135 mains. Once the rpm's are up it's fine it just stumbles on acceleration.

wkrizan 10-17-2009 09:01 AM

Quote:

Originally Posted by lance328 (Post 118386)
I just got off the phone with him, he did K&N replacement filters not an ear shave. He's basicaly stock with open exhaust. I told him a couple of things to try, and that he might need to baffle or go with #40 pilot jets and #135 mains. Once the rpm's are up it's fine it just stumbles on acceleration.

Did he adjust his air/mix screws out 2 3/4 turns or more?




P.S. I agree...where them damn pics of these pipes?

ohio_redneck75 10-17-2009 03:21 PM

i have done the same made my own drag pipes. have u marbled it yet? i have stock k-n filters has well. bike runs like a beast turned the AF screws to 3 and marbled and all is good

lance328 10-17-2009 04:47 PM

He's marbled and has the screws out 3.0 turns. :beerchug: I also told him since the bike was down for a stator replacement, to put a healthy shot of Seafoam in .

dirtrack650 10-18-2009 08:30 AM

But you got to look at the plugs after 30-40 minutes of riding at interstate speeds. I bet they are white. Any K&N filter should have a jet change whether it's pods or stock replacement and with pipes, a larger jet will keep things cooler and smooth. First place to look for overheating is the head pipe from the front cyl: check for color change in the chrome.

DT

ohio_redneck75 10-18-2009 09:55 AM

ill check mine today and see but it runs so good and dosent act like it running lean

lance328 10-18-2009 02:07 PM

Quote:

Originally Posted by dirtrack650 (Post 118453)
But you got to look at the plugs after 30-40 minutes of riding at interstate speeds. I bet they are white. Any K&N filter should have a jet change whether it's pods or stock replacement and with pipes, a larger jet will keep things cooler and smooth. First place to look for overheating is the head pipe from the front cyl: check for color change in the chrome.

DT

He says the plugs look good, no sign of a lean condition. There is something going on with the carbs, kinda sounds like a vacuum leak.


All times are GMT -4. The time now is 05:56 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.

 
For the best viewing experience please update your browser to Google Chrome