Modern Buddy

I'm wondering if I am hitting the rev limiter on my Buddy 125.

I am using the stock did and still have a stock transmission/validator. I am using the taller rear tire. Right around 70/72 bmph at WOT I get a miss in the engine. It's almost like the engine stalls for a very brief moment (half a second) then goes again, then stalls again when the speed creeps up to the same range. It will keep doing this cycle unless I back down a couple mph.

Does it sound like the rev limiter, or is this maybe an ignition/cdi/plug wire/stator/coil thing?

Thanks!

Sounds like the rev limiter. An aftermarket CDI will let you rev a little higher.

wheelbender6 wrote:Sounds like the rev limiter. An aftermarket CDI will let you rev a little higher.

Ok. I've heard rev limiters that work in different ways. I wasn't sure if what I am experiencing was the limiter, or something else getting flakey at high RPM.

Thinking about it, I'm pretty sure I might be up against the rev limiter. I would have expected a bit higher buddy miles per hour, but that could be because my stock (6500 mile) roller have small flat spots worn into them.

Do the Buddies have a Rev Limiter?

Christophers wrote:Do the Buddies have a Rev Limiter?

If so, then it's built into the CDI.

I'd get some properly sized pulley sliders so you're not running the engine at very high RPMs.

JettaKnight wrote:

Christophers wrote:Do the Buddies have a Rev Limiter?

If so, then it's built into the CDI.

I'd get some properly sized pulley sliders so you're not running the engine at very high RPMs.

Are you talking about dimensions or weight? I figured that you would only want to use the stock dimensions (18x14). The weight doesn't limit max speed. By the time that you get to highway speeds, the sliders/rollers should be flung out as far as they can go within the variator.

I already use a taller tire. New sliders might help a bit as my stock rollers have small flat spots.

I would really like to pick up an intake manifold spacer so that I can use the 30mm carb and upsized manifold that I purchased. That and maybe a Prima exhaust would complete my engine modifications.

I did end up trying a main jet that is one size smaller and found that I am not getting the rhythmic stalling thing. I guess this is what they call tuning.

No there is no rev limiter. Rpm is mechanically limited on a stock buddy. I've gone 78 mph GPS. I've also had the bike to 11k rpm(too little weight, too much torque spring). The cranks do not last very long at those speeds. If you want to find out for yourself install some sliders in backwards. It will rev to the moon. If you are brave and stay in the throttle it will eventually shift up the range at about 40-50 mph and the rpm will reduce. I'm not sure why it works that way but it does. A stock bike will top out around 7000-7500 rpm.

lovemysan wrote:No there is no rev limiter. Rpm is mechanically limited on a stock buddy. I've gone 78 mph GPS. I've also had the bike to 11k rpm(too little weight, too much torque spring). The cranks do not last very long at those speeds. If you want to find out for yourself install some sliders in backwards. It will rev to the moon. If you are brave and stay in the throttle it will eventually shift up the range at about 40-50 mph and the rpm will reduce. I'm not sure why it works that way but it does. A stock bike will top out around 7000-7500 rpm.

Just the reply I was looking for. Thanks! I suppose that those supposedly 'high performance' CDIs and coils don't do much of anything for a Buddy, then.

You can move the ignition pickup a few degrees by elongating the holes and getting a bolt with a smaller head. This will give you an additional 3 degrees advance for free or nearly free. I think I ground the shoulder off the bolt for clearance on one side. I think those ignition mods are all vaporware. I could be wrong though

Thanks for the empirical info!
The cutting that I feel from the 170i is NOT a rev limiter then. It feels a bit like a surge. I've installed a larger rear tire as well. It's also significantly wider and changes the handling a bit. If I hit a bump at lean the scoot' wants to pick up now. It's manageable and the ride has improved a bit.