Kawasaki VN750 Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
668 Posts
Discussion Starter #1
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:
 

·
Registered
Joined
·
149 Posts
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?
 

·
Registered
Joined
·
1,750 Posts
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
 

·
The Professor
Joined
·
3,147 Posts
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.
 

·
On His Lady Vulcan
Joined
·
1,647 Posts
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?
 

·
Registered
Joined
·
166 Posts
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
 

·
The Professor
Joined
·
3,147 Posts
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 .
 

·
Registered
Joined
·
1,750 Posts
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
 

·
Registered
Joined
·
166 Posts
ill check mine today and see but it runs so good and dosent act like it running lean
 

·
The Professor
Joined
·
3,147 Posts
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.
 

·
Registered
Joined
·
668 Posts
Discussion Starter #11
holla!

well there are some pics of the custom 2 inch drag pipes...:beerchug:
I still have the problem with the 'no power' on the bike.
Here is what i've done so far:
-air/screw mix from 1 1/2 to 4 1/2...no effect
-installed 2''X4"1/2 baffles...no effect except quieting the pipes down
-seafoamed two full tank (6 oz per tank)
-installed 4 new plugs
-bike marbled
.....nothing
Anyway now i think i know what's wrong with the D%$# thing :BLAM: i just noticed tonight that the "plug" (cork) that i fabricated a while ago for the de-goat process, fell off inside the air box ( probably got stuck into the carburator air entry as well). this "plug'' was used to plug the hole located in between the two front/rear carburator duct.
Do you think having an opened hole would affect the bike?
It is too late for me to work on it tonight and i got to go back to the "city"...i should be able to get back out there next weekend...:mad:


thX:beerchug:
 

·
The Professor
Joined
·
3,147 Posts
holla!

well there are some pics of the custom 2 inch drag pipes...:beerchug:
I still have the problem with the 'no power' on the bike.
Here is what i've done so far:
-air/screw mix from 1 1/2 to 4 1/2...no effect
-installed 2''X4"1/2 baffles...no effect except quieting the pipes down
-seafoamed two full tank (6 oz per tank)
-installed 4 new plugs
-bike marbled
.....nothing
Anyway now i think i know what's wrong with the D%$# thing :BLAM: i just noticed tonight that the "plug" (cork) that i fabricated a while ago for the de-goat process, fell off inside the air box ( probably got stuck into the carburator air entry as well). this "plug'' was used to plug the hole located in between the two front/rear carburator duct.
Do you think having an opened hole would affect the bike?
It is too late for me to work on it tonight and i got to go back to the "city"...i should be able to get back out there next weekend...:mad:


thX:beerchug:
The bike looks great!!
You need to find the cork and plug that hole, yes it would cause your problem.
Hopefully the cork fell out when you pulled the motor and did not get sucked into a carb.
 

·
Premium Member
Joined
·
4,778 Posts
Think that is the nicest wrap job I've seen!
 

·
Registered
Joined
·
401 Posts

·
Registered
Joined
·
51 Posts
Pipes look really nice.
 

·
Registered
Joined
·
668 Posts
Discussion Starter #18
That's IT! :)
She is up and running ...:) i bought a rubber stopper and plugged it in that freaking hole.
Now she is running with full power again. I left the baffles but i am thinking about removing them to see how pissed off my neighbors would be...just kidding.
She sounds fine right now but i would like to have a deeper sound..so will see!
I will post some pics again this time after she gets a bath ;) and videos as well.

Thanks guys for the help and compliments!!!!


Let it Fly!!!!!!
 
1 - 18 of 18 Posts
Top