[zhydro]

I have an 04 Bonneville 790 that I bought not too long ago that I've already converted to a cafe racer. I love the bike and the nice purr to the D&D Exhausts . Aside from the aesthetics and sound of this beautiful bike, I have encountered a problem…

Here's my problem that I've noticed when i went on my first spirited ride. The bike will rev out of gear at high rpm's if I don't shift. For instance, if I am in 3rd gear and continue to accelerate without shifting, as i reach fairly high RPM's, it seems like the the bike just kicks out of gear, no power is being delivered to the bike, hence no more acceleration, it just sounds and feels like it hits neutral, and then once i shift, it goes normal again, until i hit those high rpm's. I hope I am explaining good enough what is happening. Any help or technical support would be much appreciated. I am no mechanical guru, but I know when something feels wrong.

 

[Baltobonneville]

I think that your clutch is slipping, which has been reported often on these motors, especially if they have performance upgrades. Install some slightly stronger clutch springs. The stock springs are marginal and I suppose that they become fatigued as they age.

Some oils have a reputation for causing slippage, although hardly anyone ever reports that actually happening, so make sure that you use oil that meets the specs in the owner's manual.

I recently installed Barnett green springs, which completely solved the problem, and my motor is basically stock.

Propforward has a thread here on installing the clutch springs. It's easiest to do it when the bike is drained of oil. You'll need a replacement gasket for the clutch cover, and disconnect the breather hose from behind the clutch cover before you try to pull it off.

 

[2old2growup]

These bikes have a rev limiter to protect against auto-desruct which may be kicking in if your ride is "spirited" enough.

 

[Slinky]

Yep it sounds like the electronic cut-out. It's a weird feeling, one moment you are accelerating and the next- nothing.

 

[Von Dutch]

I think your clutch is slipping

I think so too.
Sometimes a clutch adjustment will take care of the problem (if) it is out of adjustment.
New Barnett springs will surely fix it if an adjustment does not.
Try adjusting and report back with results.

As mentioned it could also be your rev limiter.
If so you need a Pieman box.