stuttering at speed

[prairiehorse]

Ok here goes the prob.
Just did a MAJOR change to the 05 ridgeback....
-dual wimmers
-super g with taz
-600 cam
-head work from john sachs (bigger valves, heads worked, quenched, double springs)
thunderheart ignition (did NOT change coil and did NOT change dwell)

At speed @70-80mph it seems to stutter/surge.... not sure why. I know a LOT was changed all at once. Anyone have this happen.
My thoughts are:
1: do i need to change the dwell on the coil
2: change the jets on the carb. Im at @3500+feet. thinking maybe 34 intermediate/80 main and 60 on air bleed?
3: tried 3 on the ignition and 4 settings.....seemed to like 4 better, but didnt know if that caused the surge.........

Ok let me have it.....all help is appreciated.

 

[Bobby Schulz]

What do the plugs look like?

 

[prairiehorse]

blackish. Yes..... prob over fueling.

 

[erldawg]

Sounds like a fuel issue....I'm sure one of the carb guys will chime in...

Did you talk to John Sacks?

 

[Little-Boo]

Ok here goes the prob.
Just did a MAJOR change to the 05 ridgeback....
-dual wimmers
-super g with taz
-600 cam
-head work from john sachs (bigger valves, heads worked, quenched, double springs)
thunderheart ignition (did NOT change coil and did NOT change dwell)

At speed @70-80mph it seems to stutter/surge.... not sure why. I know a LOT was changed all at once. Anyone have this happen.
My thoughts are:
1: do i need to change the dwell on the coil
2: change the jets on the carb. Im at @3500+feet. thinking maybe 34 intermediate/80 main and 60 on air bleed?
3: tried 3 on the ignition and 4 settings.....seemed to like 4 better, but didnt know if that caused the surge.........

Ok let me have it.....all help is appreciated.

Sounds like you have a rich condition, I would go to a 32/78 and keep the ignition at # 4. :2thumbs:

Carlos

 

[prairiehorse]

ok Carlos i will try that tomorrow. Thanks. I hope that is what it is!
Will keep you in loop

 

[prairiehorse]

Had a 78 in main jet. Sunday....and nobody is open so i had a 68 lying around so put that in. Goin for a rip now n see what happens..... stay tuned!

 

[prairiehorse]

Ok....still stuttering/hesitating...also get a backfire thru carb. Happens at @ 1/4 throttle between 2500-3000 rpm.
Grrrrr frustrating! Ideas?

 

[wyatt580]

Thinkin... you need to play with the air/bleed.... maybe go up on intermediate. Down on main....but the a/b. Will dial it in small adjustment...keep track on paper...will take time...but worth it..2500 -3000 your transitioning to main....

 

[prairiehorse]

I will try that in a day or so....stupid work gets in the way of my tinkering on my bike...wtf! LOL thanks wyatt580

 

[prairiehorse]

Ok decided to put it on the dyno and run teh air fuel mixture.... to try n figure out this stutter.
Air fuel was right on at 13.2-13.5%....
Then started chasing the possibilities. Think i had a plug wire that was loose on the coil. Ran it after that and it seems to be fine... keeping my fingers crossed. Thanks for all the help.
main jet 78
air bleed 62
int jet 32

 

[stlmikie]

What kind of numbers did you pull down on the dyno?

 

[Little-Boo]

Ok decided to put it on the dyno and run teh air fuel mixture.... to try n figure out this stutter.
Air fuel was right on at 13.2-13.5%....
Then started chasing the possibilities. Think i had a plug wire that was loose on the coil. Ran it after that and it seems to be fine... keeping my fingers crossed. Thanks for all the help.
main jet 78
air bleed 62
int jet 32

I guess I wasn't to far off on the jetting

Carlos

 

[wyatt580]

Glad this worked for you.... I also would like to see/hear the #s on dyno... the shitty thing about a dyno is when your out runnin down the road things are diff... fine adjustments and time will dial it in....let us know if the surging {stuttering} went away....to finish a thread with the outcome would be great.....i've spent alot of time reading on lots of different subjects just to wonder if it was resolved......peace enjoy....

 

[prairiehorse]

OK...dyno results went as such. i am at @3500'. Temp was 80 degrees or so.
ran @126hp/113tq at 5500rpm. Was still climbing but popped a rocker box gasket that i must have pinched when i put it on.... oops!
As far as the stuttering.....DAMN it is BACK! Did a 200 mile run today and yup it is back. Seems right around 3000 rpm it starts to stutter/burp/surge almost like i might have a loose + coil wire, so i am gonna check that also. Possibly plug wire? Getting frustrated as i feel like im chasing it to no avail! ANY IDEAS?
I even thought of maybe water in the tank so i ran a bottle of heat through it to evap the water if any.... no difference! NUTS!

 

[prairiehorse]

Even went so far as to wonder if it was a strong crosswind across the dual wimmer causing disruption in the airflow to the carb......
Ya prob not!
But the things you think of when ur driving and getting pissed off! LOL

when it shutters i can roll on throttle and it's fine again......

 

[avdhunter]

You are leaning out at the transition. Go up on your Int jet and should fix your problem. Throw all preconceived notions out the window and listen to YOUR bike. I had to go all the way to a 35 Int on my 2004 107". It all depends on your comination. Some say to play with the air bleed to make it transition at a dif RPM but I didn't go that route. Hope this helps.

 

[bruce]

you can print out a manual from S&S for free and very helpful, If spark plugs are black you are runing rich, white lean, light brown good. inter. jet is used for most your riding, hard accel. is the main jet. idle mixture screw if adjusted right will really help gas mileage as well as other things. color on plugs we are talking the center - If plugs are black some just around edges that could be just rich cold. If adjusted right most should get 40 to 50 mpg. remember rich and lean conditions can give same problems - how the spark plugs are burning help tell you which one it is. If you want to talk, I am home most day by 5:30 pm 717-382-9983

 

[stlmikie]

You are leaning out at the transition. Go up on your Int jet and should fix your problem. Throw all preconceived notions out the window and listen to YOUR bike. I had to go all the way to a 35 Int on my 2004 107". It all depends on your comination. Some say to play with the air bleed to make it transition at a dif RPM but I didn't go that route. Hope this helps.

X2

 

[prairiehorse]

OK.... just pulled plugs. Front plug is BLACK and back plug is correct light brown....

Plug wire to front messed up?