2 stroke dirtbike motors in quads

[nacs4030]

I've read post after post about how this is a bad idea because of the vibration and the frame won't be able to handle it. I've always thought of putting a cr250 motor in my 300ex frame just because i already have everything and cr250 motors are cheap and easy to come by and very powerful. From what i've read though it's a horrible idea. I was just wondering how those little quads they use for mx that use cr85 motors bored to 90 cc's. How do those little guys get buy doing it?

[MR.BIG]

They do vibrate alot. Service honda builds a 250r which uses a 400ex frame and a cr250 motor. You should look up there website and maybe you can get some info from them.

[2muchquad]

i
They do vibrate alot

i hear that a lot.i wonder if people go by what they "heard" or what they have seen personally.i have a cr250 powered blastere that i have had for almost 3 years now,no problems.you'll notice a bit of vibration if you have the motor screamin in neutral but when your riding,its not even an issue.there are several variables that can cause excess vibes such as loose motor mounts,worn pipe springs or even bad low end bearings.do the cr 250 motor(mine is a 96 motor with newer cylinder) in your 300ex and you'll be spankin 450s with just a pipe for mods.:D

[400exrider707]

Why bother putting that engine into a blaster or 300ex frame? Why not put it into a 400ex or 250R frame? There are more parts readily available and the chassis will be able to handle the motor better.

[2muchquad]

well i already had the blaster so...mine handles great.+3+1 a arms and a +5 swingarm and suspension,it just flat out rips.it looks pretty mean too.its highly respected in these parts.its a 47hp machine:D

[EXracer83]

Do you have any pics you can email me of your Blaster? That sounds like a cool idea to do. I have a bad *** blaster but idk what I did but every mtor mount is broke except the swingarm bolt so I might go ahead and grind off all the mounts and do that. Just one ?.... where did you put the radiator? I was looking at that on my Blaster and my 400 and I can't figure out where I would put the radiator on either one of them. Thanks

[2muchquad]

i will try and get some pics,i havemy radiators mounted underneath the front fenders where they would be on a banshee

[2muchquad]

here it is,nothing special,kinda dirty though:(

[2muchquad]

picture arent that great,my first time posting..

[Toadz400]

Looks like you need to do some adjusting on your wheels...:ermm:

[ZeroLogic]

can you get clean pics of the quad 2muchquad

[nacs400ex]

Originally posted by 400exrider707
Why bother putting that engine into a blaster or 300ex frame? Why not put it into a 400ex or 250R frame? There are more parts readily available and the chassis will be able to handle the motor better.

Why? Because he can. Some people prefer to be different from the rest. There's some riders on here that can/have ridden bigger machines but prefer the smaller ones. If I remember correctly Bradley300, races 300exs and blasters.

I think in the near future, we will see the big four putting the 250f engines in quads similar to the 300ex and blaster. Creating a quad, which would be faster then a 400ex. Imagine that, the 400ex not being race worthy. Wait... I think were already there.

[400exrider707]

Originally posted by nacs400ex
Why? Because he can. Some people prefer to be different from the rest. There's some riders on here that can/have ridden bigger machines but prefer the smaller ones. If I remember correctly Bradley300, races 300exs and blasters.

I think in the near future, we will see the big four putting the 250f engines in quads similar to the 300ex and blaster. Creating a quad, which would be faster then a 400ex. Imagine that, the 400ex not being race worthy. Wait... I think were already there.

Oh I totally agree, that would be nice to see the 250F engines into some quads, even if they put that engine in the 400ex frame. The 400ex is by no means race worthy except on a local level, which is where I race mine, and if a 400ex isn't race worthy then a blaster or 300ex is definitely not race worthy.

[Toadz400]

Originally posted by nacs400ex
I think in the near future, we will see the big four putting the 250f engines in quads similar to the 300ex and blaster. Creating a quad, which would be faster then a 400ex. Imagine that, the 400ex not being race worthy. Wait... I think were already there.

You're comparing apples to oranges when you're talking about the F engines compared to the EX/Blaster engines. You're saying that the 300ex/Blaster will be more race worthy with the F engines compared to just the 400ex. Of course it's going to be, it's a much more high-technology engine. Now compare the 400ex with the 450F engines (which by the way are VERY competetive, more than the factory 450's) to the 300ex/Blaster with a 250F engine and it's far more superior in ranks of power and handling.

I'm not picking a fight with you, I just thought that when you are comparing the two groups, that you should at least make it somewhat fair.

[2muchquad]

i dont really care about competing with this and that.i just like playin around in the garage.:D i have a few buddies that i trail ride with,so i dont worry about the racing scene.i just have fun,i think thats why we all ride.if i raced i would have a 450.i also have a 300ex/350 conversion that i ride as well.old technology,sure but i still have a blast;) if somebody gives me a 400ex frame then i'll put my 426 motor in it,till then the blaster it is.plus my toys are paid for;)