I don't want to start a debate but as for the KTM idea, My cousin has an 86 350 and he has had nothing but problems with it. When it runs, it goes good and is very fast, but water keeps getting into the tranny somehow even after being rebuilt. Also if you go ahead with the KTM my cousin also told me that they used plastic crank (or connecting rod) bearings, but the honda CR 250 bearings were a direct fit for his. I don't know the year of the CR or anything but I do know that if you do get a KTM engine make sure it is at least a 92 or newer. Anything older is probably not gonna last very long.

 

There is no debate about the old KTMs, Husqvarnas...they were million miles from the japanes bikes. But since...say 95, not only do the bikes look cooler, but they are much better than the japanese, even in mx now. The KTM 125 SX is better than the CR or YZ, with less maintenance.
Don't worry about this, I would never have thought about getting an old austrian bike!! They just require too much maintenance to keep running.
PS. About the 360, I was talking about the enduro...I think the bike (in competition version, of course) won the 500cc world championship with Shayne King...can'r remember what year...before the Joel Smets years. Anyway, I think it's a good engine..but not 500cc...

 

The 2000 380SX put 50hp to the rear wheels, that would make one hell of a quad motor!! But then again so would any 250+ 2stroke.Why don't you try a 250R chassis and a CR250 motor? I have come to the realization that a new 250R is not coming, so in a few years I am going to make my own.There is a chance Honda may come out with a high performance quad using the CR450F 4stroke in a couple years, so i was planning on buying that quad, then yanking the motor selling it then putting a 250 in it, that will be the closest thing I can think of to a new 250R.good luck, don't hesitate, build a new 250R!!

 

Ever thought of a big bore kit in a 250R? You can get a 370 stroker! That thing will haul! And without the vibration problems.

 

I would suggest putting a yz426 engine in a R frame they are great engines. or if you want a big bore 2 stroke look at PSI's 425 kit I think they are very good topends they could use a little improvements but most all stuff can.

 

The problem with the 370s..etc is that...it's not the biggest available...and I might (will) regret it if I use such an engine. Doing everything myself, I want to use the baddest available. OR maybe I should wait and save lots of $$$ so I get an LSR frame ready to take the 500 engine (I think it's Lonestar who does this...maybe Laeger...can't remember).

 

Zorro plese tell me what kind of riding you do and whatkind of mentality you have?
Seriously a 370 is only for hillshoting and duning. Every where else it will be over kill. It aint cool to have the biggest most expenisve motor if it does you no good. And if you are thinking you will need more than a 370 you must have some ego issues. A ported 270 by the right shop will get you where your going just as fast. Porting is what gives the engine its power, not always displacement!

matt

 

A stock r handles very well every where. But I wouldn't trail ride it. I also know a guy that that built a 500r. He can't even kick it over. He is even a pro racer. His last name is OGDEN he live in OHIO.

 

It's not "some ego issues", it's purely ego. I don't care if it's faster or better. Just imagine I get the 370...I would think "I would have had more torque if I had a 500cc...". Controlling has to be the tough part (right now, my shee is easily controllable...no fear!).
Not that I want to go the most expensive way. I just want to go the baddest, biggest and most thrilling, and I'm afraid getting a 250 to 270 with porting will cost me way more than used 500CR. Actually, a 500 has a very smooth power delivery...it's like a powerful 4 stroke (well, almost), and without dumping tons of cash in it, you have 60hp.
My biggest concern is strength. I don't want the frame to break.

Where I ride? Where ever I happen to be!! That is rough wide trail w/ mudbogs behind mt house, wonderful wood trails a bit more north, and mx.
How I ride? WIDE OPEN

Again, yes there are big ego issues. If I bul my quad almost from the ground up, no way I wanna say when it's done "I should have done this". I want to feel that I built the baddest ATV I could. Rideable or not? Everyhting is rideable...I'd just put a thumb, since the control is more precise, and I'll get used to it. Dont' worry about that.

 

WOW after that post (Zorro's) i guess you do not care about money very much but you want the best there is out there. Leager makes a good frame that is built for a cr500 frame and that would be probaly not crack very quick and has great handeling (when you put top of the line parts on it).