engine swap

[Ocnaj]

Is there any engine swaps I could do to my 300ex? I looking for more power since three of my friends just got brand new 450rs. Have people put 400 motors in a 300 frame? If that is possible that means a 250r motor should work too right?

[ckasper18]

With the rite tools anything can fit

[Ocnaj]

If anyone has done something like this or knows somewhere to get parts to do it please let me know.

[firefighterjosh]

I have seen a 300ex with a 400ex engine at the dunes. It wasn't a just put in a bolt up though. I would just buy a 450 if you have the cash

[spraw602]

It would probably be easier to just sell your 300 and buy another quad to fit your profile.

400ex motor is a big air cooled motor. Most motors are smller than 400ex motor. All 2 stroke motors are way smaller even smaller than your ex motor.

I saw a pic of a 300ex with a 400ex motor in. The frame looked the same so i think it just needed motor mounts welded in and made.

[Stein2088]

For the time and money you are going to have invested into doing all of this you would just be better off selling your 300 and buying a 400... it's bigger thus more comfortable for you esp on those longer rides... plus a 400 is just a better quad chassis suspension ect. all in all.... sell and buy another one... the pro's greatly out weigh the cons!!!

Originally posted by Stein2088
For the time and money you are going to have invested into doing all of this you would just be better off selling your 300 and buying a 400... it's bigger thus more comfortable for you esp on those longer rides... plus a 400 is just a better quad chassis suspension ect. all in all.... sell and buy another one... the pro's greatly out weigh the cons!!!

I think that too. At less you can get a motor at a cheep price it wouldnt be worth it. Some people on here i see wanting to trade their bigger quads for smaller ones once in a while.

[2muchquad]

bs,if you have the know how it can be done.

not the one i meant

2muchquad has attached this image:


__________________
385ex all bore no stroke.
sparks BIG cam,REAL

[2muchquad]

here it is

[Ocnaj]

But buying another quad is something I would rather not do. I like the size of a 300 but I just need more power. I really don't think that a 400 motor would be worth it because they really don't make a whole lot more power than a 300. But a 250 or 450 would. And I think I would be spending less money if I tried putting a 250r or 450r motor in it. Theres pretty much only 2 main things to do this that I would spend money on and that is the motor itself whatever it is and fabricating costs. Any more opinions? Thanx guys.

[SWIGIN]

if you want easy power just build the 300.....or throw a 350x in there and build that motor

[ckasper18]

iI have built several 300ex motors port head big valves bore job 400ex carb with mods tc or sparks pipe and average 30 hp at the rear wheels very fun machine to ride and still reliable for under or close to $2000.00 Mikes Cycle Shop does a great job give them a call920-734-3363

[sandspanker]

350X engine is the closes thing that will bolt up. i have done this the back mount on the engine case is th eonly thing you will have to trim. i think it was about 2-2.5 inches off the block after that it will bolt right in.:D

[oldskoolex400]

you say the power isnt much difference between 300 and 400? i own both your crazy if you think the power close

[svahle]

I have a 250x with a 350x motor. It will hang with a stock 400ex. Also I like the fact that it is a 6 speed tranny. I didn't do the swap so I don't know how difficult it was. Anyway, a 350x motor will provide more power but don't expect to keep up with the 450s.

[2muchquad]

Anyway, a 350x motor will provide more power but don't expect to keep up with the 450s.

Sure it can be made to keep up with 450s,my 385ex does.:D