rev limiters

[300EXer]

wuts the point of a rev limiter? wut does it improve?

[danney f]

A rev limiter comes stock on your engine from the factory. It keeps the engine from over reving and tearing it apart. A Black Box Mod/modified CDI box is were the rev limit has been removed to allow a modified engine to rev higher and make better use of the power. A stock engine will hit its peak power point before it hits the rev limit, were as with most modifide engines' power peak may be above the stock limit of the CDI box.

[oregonrider89]

They aren't worth the money if your enigne is stock, but like danny f said with a modified engine they work well.

oregonrider89

[danney f]

Yea' on a modified engine they work well, but I have read many times on here that on a modified 400 that you still don't need a black box. That all it does for the 400 is pretty much make it harder to start.

[KAWSAM62]

the hard starting problem is commonly caused by a weak battery a good charged bat and a cdi box will start fine:blah

[QuadTrix6]

if you do run an aftermarket cdi box are you risking blowing up your engine, how reliable is it? and is it common that people mess up there engines?

[KAWSAM62]

some say yes some say no ive had one for 2 years with no problem but i dont abuse my motor i use one off a xr250 that gives a better advance curve just pulls harder at any rpm especialy in soft sand i have no dont if you were to just hold the throttle wide open shed blow but thats were common sence comes in hope this helps:cool:

[OutlawEX]

Originally posted by 300EXer
wuts the point of a rev limiter? wut does it improve?

You are gonna hear alot of stuff on theses and if there is a difference between performance,in my opion i could tell a difference when i bought mine but others say they didnt...

[oregonrider89]

Like KAWSAM62 said, with a little common sense you won't have any trouble. Mine works great with my engine mods, I haven't had any trouble starting it and it was recommended by my engine builder. I do wonder if the White Bros. differs from say your xr250 box? I know my WB box lits the engine rev higher, but I don't know if it changers the ignition curve.

oregonrider89

[danney f]

Is there a cdi box for the 300's like theres the xr250 for the 400's?

[KAWSAM62]

i heard a lot of problem came with the wb box and ive never hear of anyone say it pulled harder with the wb but i positive that the xr 250 box pulls harder and the only problem that ive seen is when a buddy left his light on a long time while camping and in the morning the bat was turning the motor over to slow to start so we put the fact box back in started it charged the bat a while put the xr box back in never had a problem the rest of the trip and he didnot leave his lights on anymore for any length of time after that with no incident i like it even have one on wifes stk 400, hlps her pull true the sand hope this helps