440ex rev limit?

[ugottabayou]

Well I might have a chance to buy a 440ex for a decent price. It is my cousin's fiance who has it, and he is letting me pick the quad up and take it to the dunes for a test ride. (I might post some pictures thursday if i get some).

I was talking to him about all the mods, like a-arms, axle, carb, etc. and i asked what difference there was between the rev limit on the 440 compared to 400. He thought the stock revbox limited to about 10,500, but he has one on there that would allow it to rev around 14,500. I think this is pretty damn high, and i'm already pretty anal about rev limits.

If i buy the quad, or when i pick it up tomorrow, would it be better to put the stock revbox back on just for added security to not blow the motor?

[Jared Coderre]

In theory you concerns are valid. In practice consider that the modifications to the engine have moved the power band to a different RPM range.

There is a potential that the power peak may occur at a place in the RPM range outside the OEM rev limiter.

I do not know the torque or HP curve for a 440. I assume that the reason the aftermarket rev box was installed to make use of this power.

Just my .02

[underpowered]

weel two things. teh 400ex stock is limited to 9250 i believe, i know it is atlease somewhere right around there. if the rev limit is raised it will not be by 5000 RPM, probably 2000 at teh most to kae it rev out to a little over 11k.

but like Jared Coderre said, mods will usually raise where teh powerband comes on at. most stock quads peack at about 6-7k so by 9k they are well below peak making little power, mods will allow them to continue to make power into higher RPM ranges so that is why the use of a higher rev limit is sometimes needed.

itis up to you on what you do, it depends on how you ride it. i have a stock rev box and rarely hit the rev limit on it, only on MX tracks will i bounce teh rev limiter before a few jumps.

[250X_project]

I agree. I have always heard it to be around 9Grand. 1450 is a hole lot of cranking, most street bikes don't even wind that high..... Also if you wanted to get just 800 more RPM to get to the power-band w/o a lot of abuse go with a stock XR250 CDI. Many after market boxes are just that...a stock one for a XR250 Dbike. ;)

And one final thought- a lot of 440's have been used and abused, so be careful. Test it out fully. Check the oil color, air filter cleanliness, play in any fittings (especially the tie-rod ends-handle bar movement w/o the wheels) check the frame for bends and welds, Warped rims and/or axle ... They are a great machine, just beware.