What could this be ?

[Guest]

When I'm holding a steady speed 50 MPH and above. I noticed the bike feels as if someone is lightly putting the brakes on and letting off. The RPM's stay the same no drop. 4th or 5th gear above 3000 RPM. Is when I notice it the most. Accelerating no problem. At first I thought the engine was cutting out. But now I'm thinking drivetrain. It happens on a nice steady interval like smooth, drag, smooth, drag. Any Ideas what this is?

 

[kirkn]

How frequent? On/off every 1 second? Every 30 seconds? 10 seconds drag, 1 second smooth?

Very curious....

 

[Steve]

Sounds like typical lean jetting. :-k

.

 

[Danjal]

Your gerbil is getting tired running circles on that wheel powering your crank.. Pull over and give him a 15 min break.

 

[tkent02]

Vacuum leaks, clogged jets, improper jetting, something is causing it to be too lean.

 

[madjack57754]

Tight spot in the chain?

 

[Guest]

How frequent? On/off every 1 second? Every 30 seconds? 10 seconds drag, 1 second smooth?

Very curious....

approx.5 seconds smooth 2 or 3 seconds drag. Only when the throttle is held still.

 

[Guest]

Sounds like typical lean jetting. :-k

.

The jets are stock. I checked the sizes when I cleaned the carbs about last Nov.

 

[Guest]

Your gerbil is getting tired running circles on that wheel powering your crank.. Pull over and give him a 15 min break.

I'm trying to get that gerbil to stop smoking. He's hardheaded.

 

[Guest]

Vacuum leaks, clogged jets, improper jetting, something is causing it to be too lean.

I have my Airscrews open 4, 1/4 turns. How do they run if there open too much? Is that a lot?

 

[Guest]

Tight spot in the chain?

I check for that its OK. I have 2 Daughters myself..And a 12ga.

 

[Guest]

Airscrews

Airscrews

Guess I will open the Airscrews more and see how it doe's.

 

[Guest]

Shim the needles.
Replace the stock plastic spacer over the jet needle with less heigth of washers
OR
Fix the ail leaks in your air box and intake.

 

[Guest]

Shim the needles.
Replace the stock plastic spacer over the jet needle with less heigth of washers
OR
Fix the ail leaks in your air box and intake.

Thanks, I'll check for air leaks first.

 

[Guest]

No air leaks

No air leaks

I opened the airscrews to 4 and 3/4 turns. It still seems to labor a bit off and on, running at steady speed, but the only new parts I used was gaskets and piston rings, valve guides. I had the head checked out at a shop. when I put this bike back together. Maybe its as good as it can get. When running it hard through the gears it don't miss a beat. Pulls strong.

 

[tkent02]

Maybe its as good as it can get.

Um no, it's not.

Leaky airbox?

 

[Nessism]

Another vote to shim the needles. I do it on all my GS's. Runs mucho better.

 

[Guest]

I think mines lean

I think mines lean

Another vote to shim the needles. I do it on all my GS's. Runs mucho better.

This solves a rich or lean condition. Another thread on here has me mixed up.

 

[Guest]

This solves a rich or lean condition. Another thread on here has me mixed up.

It richens the needle circuit.

 

[Smokinapankake]

Seems like 4-3/4 turns out is too much, but I'm no expert. Typical settings are around 2-1/2 to 3-ish, no?