I've been looking for a nice lightly modded 400ex and came across one. Its a 2000 w/ 416 piston, hot cam, white bro's silencer, & k&n filter. He's asking 2300 for it. Is there anything I should watch out for? Is it still going to be as super reliable as it was w/ stock cam and piston? I should still be able to run 91 octane right? It looks like a great quad and would just like to make sure theres nothing I should look out for. Thanks, Will

 

That seems like a fair price, at least for my part of the country.
You should be able to still run pump gas unless he put a high compression piston in it when he bored it to the 416.
What Hotcam did he put in it? Stage I or Stage II
Stage I is for low end to midrange torque and Stage II is for midrange to top end.
It should be just as reliable as stock. It's only at the first over bore.

 

1st over bore??? No sir...for it to be at 416 it's bored about .080 over if I remember correct. Try to run a compression test on it and that will tell you if the top-end is still good. Check the frame for cracks/bends/rust. $2300 seems like a good deal for your part of the country too.

 

85mm = 400 , 87mm = 41, 88mm = 426
Those are the bore approximate cc's stock and the first two bores.
..080 is not a 416 bore. You are not remembering correctly

 

Well I got ahold of the guy, and he said it smokes some on start up. So I think I'll pass this one up. I did also find an '01 w/ 440 kit, cam, exhuast, etc. and he only wants 2k? I have yet to get a hold of him, but that seems awful cheap. Also, don't the 440's have a problem popping head gaskets? Thanks, Will