Modern Vespa

I have a 2013 BV 350 that has an issue. Only after about 15 minutes warm up, it will "skip", that is momentarily lose power near maximum speed. I cannot tell if it is the engine losing power or a slipping transmission.

I have already changed the plug and the plug cap, which caused a similar symptom a few years ago. I have also removed the evap canister thinking it was that.

What should I be trying next? Thanks....Drew

Ping! Is no one familiar?

You say it happens near top speed. Perhaps you are hitting the rev limiter?

Thanks Fergy,

I am not familiar with the rev limiter. When does that kick in and how would it be expected to act?

In my case, it has a feel like something is slipping and there is a fairly sharp jerk of loss of power. If one backs of the throttle and teases it back up, it recovers.

Right now it doesn't permit smooth operation at 65-70 mph, which was routine previously.

Drew

Sure sounds like you are bouncing off the rev limiter as mentioned.

Seems that the bike should be able to do better than 70 mph easily. It certainly did previously, something has changed. Is the rev limiter adjustable? I'd assume it is a canned computer function.

Is it possible that the dealer mapped the ECU wrong last service?

Thanks, Drew

Rev limiter engages at a preset rpm rather than road speed I believe. Certainly it's run by the computer so you might ask your tech about the remap

I'm pretty sure that PADS checks the bike model before uploading the new mapping so it wouldn't let you put the wrong one on and even if you did then you'd almost definitely have problems across the whole speed / rpm range.

the ECU in the GTS has *both* a speed and rpm limiter, I'd expect the BV to also have both.

if it was previously happy a a given speed then it should still be.

Instead I'd suggest 1) check both tire pressures, 2) calibrate ASR, 3) turn off ASR.

It does. Hilariously, the service guys at my local brand new Vespa/Piaggio dealer called me into the shop to help them with trying to clone the key fob on my BV400 since I'm a software engineer, so I saw it up close. You have to key in the VIN before it lets you update the firmware on the scooter/etc

Slap this puppy on there. Fixed my 2014BV with the same symptoms. It's still a gamble though.

https://scooterpartsco.com/bv-350-c-108_3545/malossi-force-master-cdi-for-piaggio-bv-350-p-802.html

Thanks all!

No ASR on this model to turn off. 2013, USA model.

I guess its to the dealer then to check it out. Was hoping for some things to try but I guess I've exhausted them. Bike always did 85 mph easily and the problem occurs earlier than that, more like 60-65 mph after 15 minutes warm up.

Drew

If your ECU needs replacing. It's going to cost you 3 times as much as the CDI. Your symptom description is exactly what my bike ran like if I removed the CDI.
ECU = $350-$500. Labor = $150 per hr.
I replaced my ECU for $350 on sale. The replacement failed after 20,000 miles. I swapped the CDI from the custom bike to the commuter and that fixed it.

I forgot to ask if you still have the evap crap on the bike? Lots of info in the search. It would suck to spend a lot of money for something so simple.

Evap crap is removed.

All,

I need more advice. I have not ridden the scoot in about 2-3 weeks weeks and decided to try again before it goes to the dealer. The symptoms were much different yesterday.

Immediately from cold start (and forever after) the bike pulses and bucks at about a 2/second rate as soon as you try to accelerate from a stop. If you pump the throttle a bit and tease it through that range, at about 35 mph it becomes smooth and runs 100% fine. You can slow down almost to stop and and it is still fine. When you do finally come to a stop, the bucking will all repeat again. No change with warmup.

I have already changed the plug, plug cap, removed the evap crap, put clean gas and Sea Foam through it, etc.

Any ideas please? I'd like to fix this myself if possible. Not thrilled with the dealer.

Thanks,
Drew VS

So my idea didn't work?