thinking of going hybrid crf... couple general questions

[400exracer511]

So I'm thinking of either trying to build or buying a crf/ex or r hybrid and I have a few general questions for those of you who have alot of experience with them.

1. How is the reliability of a bike motor in a quad chassis? I would think since they were intended to pull around lighter bikes that would affect how they last pulling the extra weight of a quad? How does the tranny hold up over a few years?

2. What is the power of a crf stock w/ pipe/filter/jetted righ compared to the 450r/yfz450/ltr ect.?

Thanks to anyone who has answers for me.

[400exracer511]

Also if you could post what you like least about your hybrid that would help alot, be sure to include what motor/frame combo you have ...

thanks again

[mojohoits]

as far as the engine pulling a lighter bike to a heavier quad i was worried about that too. my old quad was a frontline 250r frame and i put a crf 450 engine in it. the engine had no problem. didnt slow it down at all. nothing to complain about for the hybrids as far as mx. little to jumpy on trails but thats it.

[Rootar]

if your planing on using a 400ex stock conversion forget it, i would only build a 400ex hybrid agian if i could get my hands on an aftermarket frame. If youll notice in my sig i have a full out atv fourplay conversion frame crf hybrid and ive prolly spent tripple the time wrenching as i have riding atleast i checked every single bolt before every ride and ive broken the snot out of my frame and right now its being stripped down and having 4 tubes replaced becasue they were beyond repair and then just about every weld gone over due to stress cracks and jsut clean breaks.

trust me its not the cheaper route to go for more power.

if your set on a hybrid they are awesome quads jsut as long as they are built right and on a good aftermarket frame.


mine easliy runs dead even with full piped and camed 450s, i have the 05 motor it has the better electronics and a better cam grind over the older motors from what im told.

Reliability is great other than the damn water pump seals, change the oil every ride or every other ride and jsut keep good check on the vavles and such and thats about all

[BuiltBlaster88]

I can't speak for the crf guys..but I did the yz 426 conversion on my stock 400ex frame, and it turned out great. I wouldn't recommend doing it yourself unless you are a very competant welder, but then again..I prolly wouldn't do it again on a stock frame. It's imperitive that you at least have aftermarket suspension, if not long travel. 45-50+ hp on a stock stance isn't safe nor wise. After about 15 hours of ride time I managed to put a few cracks in the frame, but I beefed the whole frame up considerably more over my winter rebuild, even more so than it was before. But hey, my labor is free, and aftermarket frames aren't cheap!! As far as the engine goes, the yz has held up great. A larger aftermarket twin/triple core radiator will be money well be spent. It's hard to keep these suckers cool. I wouldn't build one for trail riding...only mx..as I really have not been able to keep mine cool for more than about 30 mins at a time, even having the carb jetted on the rich side, runing engine ice, and a 3 core oversized janssen radiator. We'll see how it holds up this year.

[joeb23]

Originally posted by BuiltBlaster88
I can't speak for the crf guys..but I did the yz 426 conversion on my stock 400ex frame, and it turned out great. I wouldn't recommend doing it yourself unless you are a very competant welder, but then again..I prolly wouldn't do it again on a stock frame. It's imperitive that you at least have aftermarket suspension, if not long travel. 45-50+ hp on a stock stance isn't safe nor wise. After about 15 hours of ride time I managed to put a few cracks in the frame, but I beefed the whole frame up considerably more over my winter rebuild, even more so than it was before. But hey, my labor is free, and aftermarket frames aren't cheap!! As far as the engine goes, the yz has held up great. A larger aftermarket twin/triple core radiator will be money well be spent. It's hard to keep these suckers cool. I wouldn't build one for trail riding...only mx..as I really have not been able to keep mine cool for more than about 30 mins at a time, even having the carb jetted on the rich side, runing engine ice, and a 3 core oversized janssen radiator. We'll see how it holds up this year.
3 core radiator? do you have any pics? I recently bought a afco dual pass radiator from janssen waiting for it to get here...

[badquad]

So if you guys had the chance again you would go with aftermarket frames.. Now if you did not have enough $ would you just do a bore out on the 400EX, like the 460 or 440? I will be getting some money in may,
$2500. and I want more power from my 400. I have everything I need for the 400, but lack the power now a days to keep up with the 450's. I can keep up on the trails, but once we get in the wide open spots I get left behind about 4 bikes. Any suggestions which way to go? Hybird with a new frame and my parts off the 400> Or a big bore on the 400? Or just get a powervalve for my 250R??