rev box question

[BassHunter0123]

is it worth buying a rev box on a basically stock motor?

[honda400ex2003]

no, A stock 400ex makes peak power at 7k RPM, the stock rev limit is 9100rpm so higher revs gains nothing on an internally stock EX engine.
steve

[BassHunter0123]

thanks

[honda400ex2003]

no prob. steve

[BassHunter0123]

if a high rev box would not do much on a standard bore motor, why would curtis sparks say that the timing key works great with high rev box's having that they dont recommend using key on a bored out motor? any thoughts on that???

[Wheelie]

I've ran both with my setup, minus the E-85. The rev box made a very small difference in low end--no noticeable difference in top end power, it also caused some starting issues and an unusual 'kick-back' sometimes when I shut it off. I removed it after 2 months.

The Sparks key made a very noticeable difference in power from bottom to top. It's staying.:macho

IMO--Rev boxes are crap, unless it's from an engine builder like GT Thunder.

FWIW--I rarely hit the stock 9100rpm rev limit with my setup, the conservative stock rev limit is cheap insurance.

[honda400ex2003]

if a high rev box would not do much on a standard bore motor, why would curtis sparks say that the timing key works great with high rev box's having that they dont recommend using key on a bored out motor? any thoughts on that???

Unless you get a cdi with a timing curve advanced on the rpm increase doesnt do any good there is no power anyway. the key is a different concept on what it does it advances the timing ot help get a more complete burn of the fuel by making the spark happen sooner. steve