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So after ALL the work we’ve done, we’ve finally got her ready for more upgrades. We’ve topped at 20.3 hp via the dyno tune. Got a map that fits us perfectly. Now, I have a few questions for the community;

1. we hit the rev limiter SUPER fast. Then I’m just sitting at 67 mph, and won’t budge above that. (I’m 6’3” and 320). It’s crazy quick to get there but I feel like if I have more rev limits to go, I could take it up a notch to maybe 73-75. So finally, is removing the limiter a thing?!?

2. how badly do we need a new fuel injector? Because I’m not sure about the limitations of the 125 injector, but could think that it’d be great as much as we are putting through it right now.

3. How badly would it mess me up to put a 4.5 inch stretch? Saw one at MBNTHBX, but not sold on it. However popping the wheel up in third is scary lol
Any and all help I can get I will take, hmu and keep me posted.
 

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1. Lots of people raise the rev limit on these BBKs to get more top end out of them. However (and this is a big one), the weak link on these kits is the piston. And if you rev the motor too high you may pull the wrist pin out of the piston. It's luck of the draw

2. When you start raising the rev limiter, you run out of duty cycle with the stock injector. If you decide to raise the limiter, most people go with the Ninja 300 injector.

3. I'll refrain from giving my completely biased opinion on how stupid stretch kits are.
 

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I don't know much about the high performance mods but will add what i can

#1 See my chart on that below for rev limiter issue (pic 1)

#2 Pretty sure everyone with the higher performance motors use the ninja 300 injector, but wait for there input on that (pic 2)

#3 Again, pretty sure the 4.5 affects the handling to much for those pushing the limits while riding, but depends what your using your bike for and your personal needs. there are 2-3 inch longer types of swing arms available that I'm seeing that most prefer doing that keep the better handling still (pic 3-4)

1 TOP SPEED OPTIONS.JPG FUEL INJECTORS.jpg s-l400 (3).jpg 83853849_2461892690689325_2337677311106613248_n.jpg
 

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Over 20 hp with stock injector? Interesting.
Def would be interested in some dragy or 1/8 mile track times.
Are you geared down quite a bit to pop wheelies in third While accelerating? Or are you just clutching it up?
 

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I hit 100% duty just before 10k RPM with the stock injector at 12.8 AFR.
I figure I'm making 16-17whp or so with my setup.
At 105cc and 43PSI rail pressure, the stock injector is good for about 17whp @ 100% duty or 14whp at 80% duty.


20+ whp on the stock injector would be crazy lean at high RPM. Like meltdown time.
 

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Add the crank. The 155 is as big a step as the 144 was.
Don’t raise the rev limit either way. Makes these fantastic kits a bit of a time bomb.
You’ll have all the power to raise the gearing and add 5mph without raising the revs.
Our stretch is only 4.5”, because lots of testing proved that was the perfect length to add stability, and not hurt handling in the process.
 
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