Tao Tao Racer 50- BBK 80cc - Rev Limiter?Loss of Power

[ae0622]

Alright guys, i'm needing your expertise on this.  I dont know if I just need to be patient or need to make adjustments.

I bought this Racer 50 from a scooter shop and they installed an "80CC" kit on it. Engine: 1P39QMB Engine - 200 Miles on it

I don't ride WOT very long because of the break in period, but when i do, it Revs up to about 8500 RPM.  On a long road, I kept it right under 8,000 RPM, and about a 1/2 down the road, i lost engine power.  The engine did not CUT OFF.  The REVS decreased, so i let off the throttle and then began to ease on the throttle and surprising, it responded normally...i kept it at 7500 and was absolutely fine.

I called the scooter shop and they said i must have hit the Rev Limiter. i was told by another owner of the bike that this does not have a rev limiter...... Does this sound like a rev limiter?  There was no sound whatsoever except the engine slowing down.

If that is a rev limiter, that brings me to my next question.   Should I be hitting the rev limiter at 3/4 throttle?    Is this due to the break in period?  I have a feeling it's the weights, but I'm uneducated. I am 130 pounds, so i dont know if my weight has any bearing on what roller weights to use.  OR should i expect the RPM's to get lower as the engine breaks in?

thanks 

[bredfield63]

I would raise the roller weight,the racer 50 comes stock with 5g rollers, I would think 8g or 8.5g to keep the revs lower, I think 8- 8500 is too high especially for break in period, it may have been overheating on you, You can ask the shop what roller weight they put in if its not on your receipt also ask them what the upjetted the main to, again if its not on the receipt.also did they install a kevlar belt when they did the install? if not I would highly recommend purchasing one and installing it, or you will shred the original belt for sure. my 2cents

[ae0622]

Thanks Bredfield. How's the racer 50 running with the 100CC BBK? Was thinking of installing one later but heard it causes a lot of problems.

[mrkswthwrth]

Eyyy another racer 50 owner! Good luck with it buddy.

[bredfield63]

Have not had a problem with any of my 100cc builds, 2 have a bit over 8k on them.

[ae0622]

I have 200 miles on my bike and 80 CC BBK. Being a lighter rider, I would have thought I'd be getting a little faster than 40 MPH on flat roads, but that's about what I am getting. 42 on slight declines. Is it because the engine isn't fully broken in? Or do you think it's a tuning issue.

[bredfield63]

1st don't try to go 40mph with a motor not broken in, next,what is your main jet size, what weights do you have in the variation? do you have a performance exhaust and free flow air cleaner, or stock airbag and muffler, are you running lean? lots of little things can keep you down, I am having the opposite problem, I am having to keep an eye on my rpms I keep getting up past 8500 and hitting 48-50 on the chinese speedo, so maybe 45 or so by my gps, the racer 50 must have a higher gearing cuz it flys off the line and revs too high for my liking, still zoning in on mine,

[GrumpyUnk]

Make sure your fuel flow is not being limited. Would hate to be running at good rpm with the mix going lean due to partially plugged filter or restricted fuel flow. Cook & melt the pistons.
tom

[llvllo]

Hello, I am new here and just recently purchased a Racer50 and had a few questions that hopefully someone here could help me out with? But first I thought I would like to give feedback about the possibility of a rev limiter on this model. From what I can tell there is infact a rev limit, my stock Racer50 seems to cap out at 7500-800 rpm however going down hill I have pushed over the limiter at 8500-9000 rpm. On one single occasion it hit 11k down hill (55mph). Now my question is about the digital display on the 2017 Racer50, how in the world can I switch it to mph from kmh? I have tried various methods using the 2 buttons on the front of the display and nothing seems to work.

[ae0622]

Hold down the right button until the display switches

[mrkswthwrth]

I have found the same to be true on my racer50, however the fact that it will go up to 9-11k rpms without cutting means there is no rpm restriction. The engine simply doesnt have the power to push the bike on flat ground higher than 7-8k rpm.

And as far as the speedometer, read the manual.. it's in there.

[llvllo]

The manual only shows the non digital gauges. I have looked it over. Pressing the right button usually just changes between the trip meter and odometer. But I'll try it again.

EDIT: Pressing the right button and hold got it to switch thanks again.

[mrkswthwrth]

Ahh try holding both buttons.

[llvllo]

Got it to switch thanks again