i'm wondering if it would be possible to put a 700cc or 800cc engine in a 400EX. i'm thinking a 4 stroke engine, not jus for drag racing, i'd use it as an all around quad. how much would a motor like this cost? what other modifications would i need in order to make this work? would puttin and like this in the quad even be worth it? or could i spend the same money and get a raptor and a bunch of mods? thanx

 

If you have good fabrication skill, it wouldn't be much of a problem. I would prefer a twin, over a 4 cylinder, mainly because of weight. I am going to build a 800cc or bigger next year. I think it's better when you build your own, than buy one! Look at it this way, no one else will have one like your's, when it's finished![img]i/expressions/face-icon-small-tongue.gif[/img]

 

that would be a really fast quad, but why not put it in a different frame? i don't think i would put that size of an engine in a 400ex frame. just my opinion

 

There arent many spots for a radiator either.

 

Yeah the 400EX frame wouldn't be my first choice. Could be done tho. I wonder if one of the old 650-750 twins could be made to fit? There were a ton of those around in the late 70's early 80's. Theyre air cooled so you wouldnt need to worry about a radiator. Reliable engines to. I had a old Yamaha 650 that went 65k without a rebuild. Not bad for a 20 year old air cooled twin. Of course the power wouldnt be anywhere near as big as a newer water cooled motor but it'd be a big jump from the 400ex engine.

You would have to come up with engine mounts and an exhaust. Beyond that it's mainly a matter of fitting the whole beast in there....

I've never done this tho... just speculation.

 

Get a Suzuki SV650 engine (70hp)... Could be fun....

 

Yea SV650 would be a good choice.

 

I have pondered this question myself. I have a 1976 kz400 motorcycle sitting around. I wonder how big I could bore that out(its a twin), and what I could do with it.


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86 trx250r
97 warrior