Rev Kit ?

[BBW]

I see a lot of talk about rev kits which as I understand it will allow the engine to rev from 1000 to 1500 more rpm’s give or take a few. My question is this… without a rev kit is there something that prevents the engine from revving to high and if the answer to this is yes what happens when it reaches that predetermined RPM? When I’m racing I’m not sure I would want to wind it out any further than I already do.
Thanks for whatever info you can give me.

[j4rdemotox]

Your quad has one on it from stock. It allow you to rev up to 9200rpm +/-. If you are racing I recommmend putting on a Rev. kit. The honda motor can handle reving higher than 9200 RPMS.

You will not hurt a honda motor!

Note: Use the knew Rev Kit wisley

[BBW]

Okay so what happens when it reaches 9200 rpms? Will it not rev any higher, does it shut down or what?

IF your motor is stock your wasting your time.. Dyno's prove that a rev box does nothing to a stock motor. Your power drops off to early to benefit from it. Your just reving the piss out of your motor for nothing is what it boils down too....:eek2: GT thunder has dyno's on their webpage if you'd like to see..:cool:

[4TraxRider]

To see what happens at 9200 RPM, when your EX is warmed up, put it in neutral and hold it wide open for a second. It will kind of spudder and pop a little. If your not hitting your rev limiter and you can't feel it, you probably won't benefit from one.

[F-16Guy]

You don't need one. A stock motor doesn't make power that high in the rpms, and if you're revving a four stroke that high on a consistant basis, you should think about getting a 250R. Most are XR250 ignition boxes, so if your battery isn't hot, the starter won't turn your motor over fast enough to overcome the anti-kickback circuit (bike won't start). Use that $100 to buy something that will make a difference.
BTW--DON'T free rev your bike until it hits the limiter!

[j4rdemotox]

4TraxRider is right on!

A good ? is can you get a rev box that is adjustable.

RICO YOU BROUGHT UP A GOOD POINT. MY GOOD FRIEND HAS A REV. BOX WITH A LITTLE MOD. I ALWAYS TAKE HIM IN A RACE. IT SEEMS THAT @ A CERTAIN POINT HIS POWER DROPS OFF. I AM GOING TO LOOK INTO THAT.

[BBW]

I don't want one. When I grab the next gear I'm reving as far as I want to go. I was talking this week-end with someone that has one and curiosity got the best of me as to what happens on a stock machine when you reach the max rpm's. I had a car once that when you hit red line it was like you turned off the key. I'm still not sure the question has been answered.

[F-16Guy]

Originally posted by BBW
I don't want one. When I grab the next gear I'm reving as far as I want to go. I was talking this week-end with someone that has one and curiosity got the best of me as to what happens on a stock machine when you reach the max rpm's. I had a car once that when you hit red line it was like you turned off the key. I'm still not sure the question has been answered.
It cuts the spark for a split second until the rpms drop below the limit.

[j4rdemotox]

It will not shut off. It will just spudder or pop.

I have a Chevy that will shut off

[BBW]

Thanks guys. I'll take your word for it.

[03400EX_Nacs]

as its been said before that a stock ingine it would help and that you were wasting your time but what do you consider stock and not stock?

[JOEX]

Don't most aftermarket CDI boxes change the timing advance curve as well as upping the rev limit?

Joe

[cals400ex]

Originally posted by JOEX
Don't most aftermarket CDI boxes change the timing advance curve as well as upping the rev limit?

Joe


i know the aftermarket boxes say they change the spark curves and rev limit, but i can't tell a difference in power besides the raised rev limit.

[j4rdemotox]

If I have a E-Series pipe, Jet Kit, & K&N Filter could I put a rev box on & gain? Or will it not help unless I have a 416/426 kit?

[wilkin250r]

Originally posted by j4rdemotox
If I have a E-Series pipe, Jet Kit, & K&N Filter could I put a rev box on & gain? Or will it not help unless I have a 416/426 kit?

It's not so much the bore, but more of a compression and camshaft issue.

Friction, the force of moving the piston, and all the internal forces increase with RPMs. These forces rob your power. Eventually the internal forces are greater than the available power from the engine, and the net result is that you have no more power output. All the energy is spent just keeping the motor revved so high, that no power actually gets to the wheels.

A higher compression piston will have a little more power available up top, so it takes a little longer to reach that point at which the power drops off.

A high-performance camshaft takes advantage of certain high-RPM characteristics, so it build more power at high rpms. Again, since you have more available power up top, you can rev out a little further before you hit that point at which the power drops off.

A big bore has a bigger piston, which means more force is required to throw it up and down through the cylinder, which increases the parasitic forces inside your engine. Typically, a 416 will out-rev a 440 because of the difference in piston wieght.

The rev-limiter cuts the spark at a certain RPM range. Without a spark, obviously your engine RPM will drop until you get below the RPM limit. At that point, your spark will fire again. This is why you get a sputter and pop when you hit the RPM limit.

The inertia of the piston going up and down is creating stresses on your connecting rod. The faster the piston travels, the greater these forces are. If you rev too high, you can actually break your connecting rod. That's the point that your motor blows up.

[j4rdemotox]

Exactly!!!! Thanks