Questions about modding an old motor

[satanspetferret]

After having riden my stock '96 300ex for almost 6 years, I've decided that it is time to bust out the modifications. The only changes so far on the bike are new front shocks and smaller rear tires. Because of the small, wussy nature of the 300ex, I am constantly riding WOT at high RPMs and shifting gears very often. Surprisingly, the engine burns no oil.

I'm worried that although the motor may not show it now, it might be pretty tired and I don't want it to self-destruct on me. The mods I'm thinking of:

Exhaust (Custom T-4 Shorty)
Wiseco 11:1 Lightweight Piston
Lightweight Flywheel
(I've heard that P&P is extremely helpful for the 300ex, if someone confirms that, I'd appreciate it)

Opinions on whether the motor will last much longer with these mods?

[K_Fulk]

If it makes you feel any better you could inspect the bottom end for wear. Such as bearings , tranny gears and forks, crank, rod , etc. And replace what is getting bad.

[2muchquad]

i just put a high compression wiseco piston in mine and 2 new intake valves and i run the snot out of it!i just inspected the crank while the top end was off and i gave it the "good to go":) its a 95 300ex still going strong.

[44oEX]

a really good cheap mod is to put a 400ex carb on there. it will really wake it up.

[Cody_300ex]

That sounds like an awesome plan. Like 2much quad said I reccomend two new intake valves, They tend to be softer than exhaust valves. You should also get a stage three web cam from www.webcamshafts.com . I did a 4 angle valve job and a P&P on my 300ex head myself and it helped ALOT, It even gave it a deeper tone, and faster revs, almost sounds like a 450! I am getting a lightened flywheel also within the next month or so and i've heard good things abotu em.

[satanspetferret]

Is it necesary to replace the valves after a port and polish?

[44oEX]

no, if the valves are good you don't have to change them

[hondardr4life]

Those are almost the exact same mod's I was going to do to mine until I decided to do the 330 kit. I think those mods will wake it up a good bit. The only reason I went with the 330 was that I saw an article on one in 4 wheel atv action where it was dead even in top end with a z-400. I have heard that 330's are very reliable, and I haven't had any problems with mine yet (knock on wood). The only thing that I have had go wrong so far is the screws fell out of the carb and I bent my stock axle today:(