I have seen several people on here that have done the 350X conversion on a 250X frame.What is an estimated cost for that project with just a stock 350X motor w/ 250r/400ex front suspension with shocks and brackets and a 350X swingarm and axle or swingarm and aftermarket axle for the rear.I know where I can buy a 350X bike in excellent condition but I dont want to spend alot of money on a bike that im just gonna strip down for parts.Ive already got a 250x and also another 250x frame(no motor or suspension) and am looking into this conversion if the price isnt too steep(due to a new baby and one income).Thanks for all your input.Oh one more thing,I want to put the new yellow 300ex plastic on but is it cheaper or better going through a company like maer or are fenders through honda reasonably priced?Im not too much into the one piece fronts since I want the gastank cover a different color.I might as well get all my questions out in one sitting,I saw a 300ex with what looked like a k and n filter but the airbox was removed.Wouldnt it suck too much air?It looked pretty tight with just the filter exposed but didnt know if it affected performance.Thanks.

 

You'd be better off to just sell the 250X's you got now save your money and buy a nice used 400EX, that way you'd have a faster machiine then the conversion, better handler and all the parts would be fairly new. You can get a nice 99' for $3500 or less in some cases.

 

I agree with KILLER250R, that just doesn't sound right, lol j/k KILLER250R. But I would just go with a 400ex unless your just looking for a project, which is what I was doing. It was/is a awesome project though. It really couldn't be any easier. If I was to put a price tag on everything it would be: $930 for a brand new '86 350x motor, $150 for used wiring and new cables, $100 for used 250r arms, $400 shocks (ohlins) and to have the frame modified, $250+- for frame powdercoat, $120 for used custom made exhaust pipe and silencer (400ex), and a bunch of cash for misc. stuff thats not needed for conversion (rims, tires, bars, plastic, etc...). That's almost $2000! what the he!! was I thinking? You can deduct $550 cuz the ohlins shock and powdercoat. It should be an awesome bike though. I haven't got to ride it yet because I need to take the motor back out to shave down the oil line bolt on the head to keep from hitting the frame and see why it's leaking, probably cuz of that. It all depends if you buy new or used, you can save alot buying used, ebay has been good to me. You probably can save alot by buying a good 350x and using as a parts bike.

The problem with the straight filter and no box is not too much air it's just alot of dirt would be mixed with it. Running no airbox is generally just for racing.

Hope that helps ya weigh your options.

 

depends on the year of the 300ex and the shape of it. LOOK around cause the cost to convert isn't cheap but its not as exspensive as some people say. the whole 350x bike cost me 1000 bucks and the conversion kit costs 435 for the pipe and 70 for the instructions and motor mounts. so if you find a motor cheap enough. it your choice to see what is more cost efficient to you.

 

really cause i seen a 250X/350X quad at a race and it was destroying 400's, 350X's are bada** machines, those things rip.

 

Yup a 350x engine in a 250x or 300ex quad smokes a 400ex with the greatest of ease. Make that 350x a 425x bigbore and enjoy smoking any other larger 4stroke quad u can think of. Id even be willing to bet youll be able to hang with modded banshees as well.

 

i thought so, 350X's are bad machines, one of the quickest 4 strokes i ever seen, I'd love to see someone with a 350X beating the crap out of the new 450s.

 

I know this is a old post but I'll add some info. This conversion really lets the 350x engine run wide open without trying like crazy to keep it under control. My 250x/350x will beat a 416ex in a 300ft drag and on top end with a 13-37 gearing. Kepp in mind that the engine in mine is brand new bone stock except for the bolt ons. If I don't sell it I am gonna put my other 350x engine together with a high compression piston and ported head with a lager cam, so I can beat the 450's. I did drag race a couple 450's with it this way and got beat by several bikes in a 300ft drag, but I think with the other modds, it won't lose again. The 450's that I raced had pipes for sure but thats all I can verify. RUSS

 

I guess I should add my 2 cents here.... (see username)

You guys are slightly overrating the 350X.

I had a pristine 85 350X, (which is lighter than than the quad convert, of course) and my buddies 01 Raptor would pull it after 2nd gear or so pretty quickly.
We were tied in first.

Im sure it would have beat a stock 400EX, though. I believe stock 400EX HP average is around 26-28HP, and the ol 350X was putting out around 23 HP.
Although very torquey for the light front end, it wasnt the beast you guys are making it out to be. (not to discredit it though, it was a great bike!!)

Someone said something about the X beating up on 450's and such? That is.... far fetched to say the LEAST.

That being said, I did love me 350X and I have pictures of it here, under the past bikes folder.

 

Yes you are correct. The post of a 350x beating a 450 is a little far fetched. But I think it would be very possible with a few mods. The 450's are fast and thats no joke. I myself was mainly refering to the 400's and maybe a few 450's after some engine mods. But actually since my ds650 will beat most out there, I probably won't even mess with the 250x/350x, it's a very nice quad but not even comparable on power verses what else I have.