Rev boxes are used so you can stay in gear for longer (aka more vehicle speed) so you don't have to shift. Just because the engine power drops doesn't mean you're still not accelerating.

 

Is it true that they don't even have grease fittings on there a arms. If so long term reliability would suck.

 

Grease fittings can leak. It's easy enough to take the a-arm off and manually grease the fittings yourself.

 

corpsie you know everything

 

hey and if you dont belive him that he knows everything just ask him he will tell you.[img]i/expressions/face-icon-small-wink.gif[/img]

 

I herd the early models had frame trouble but they fixed them for 04.

 

ive seen the frames on o4's and they look darker like a greyish color

 

Overheating: heat transfer problem.

Engine RPM's: F=ma. To simplify use the con-rod and piston as your mass. Figure out acceleration based on stroke and RPM. Remember at bottom dead center and top dead center your piston is moving at 0 meters/second. In between it's moving awfully fast.

Engine RPM's: a cyclical fatigue problem. Increased forces for a longer duration in time = an increased chance of failure.

Rev Boxes: I answered this because I asked that same question back in 2002. If you really want I can post some notes about gearing, power output and power required.

Grease Fittings: Just look at the parts! These are ATV's, not cars. Disassembly fairly simple.

[img]i/expressions/face-icon-small-tongue.gif[/img]

 

Very reliable !!!! ... there were only a handful of bad frames in 03 and so far havn't heard of any engine problems

 

yo man, the other day i was out riding my kfx 400, and i looked down and saw oil spraying every were, and theres a whole in the crank case, u have any ideas of what could have came through the case?