350x

[TRX-330]

who has putt a 350x engine in there 300's or 250x. I am planning on doin it when this one blows up again. Oh and dose it keep up with a 400 cuz my buddy had a 350x and said it beat a 400 butt that was with 3 wheels witch is lighter than havein 4.

[JIMFROMTEXCO]

I HAVE A 350X IN MY 250X FRAME. I like it when it runs :rolleyes: . its alot tourqier then the 300 motor. its sumthing you just really got to think about. it really wouldnt be worth it if you plan on buying a bigger quad. it is kinda comparable to a 400. i would say the 400 revs alot faster and is faster in a quad frame. but a little work and a 350x can be alot faster. you can get almost 500cc on just bore alone.

[TRX-330]

i dont think i will be getting a bigger quad for awhile and i like my 300 and have alot invested in it. butt next time something happens to the engine i will put a 350x in it, and later on after that i will do mods to it like i did to the 300. How much do you think i could get for my bored 40 over ported and polished 300 if the case is cracked. because i have a feeling thats what gunna happen (not really cracked butt from the chain ridding on it and wearing threw it) every time i right the chain stretches so much it starts to ride on the case, what can i do to stop this. Thanks Jake

[2muchquad]

If its not wore yet,put some jb weld on for a piece of mind and get a case saver.Also keep your chain adjusted properly.

[dork]

it would be easier to build your 300 up if you like the chassis. a 330 or 380 kit would double your hp and then you'd be going by those 400's. the 350x sounds nice and easy at first, but to do it right takes some $ and time. chances are you'll have to rebuild the 350x engine, and if you do find a good stock one, it won't be much more power than what you have now.

if your chain is hitting the cases, then its shot, along with the sprockets. there's no way your stretching that thing with your engine unless its a real cheapie. when they wear out, you can tighten it right up, but it won't fit tight on the teeth and will rub the case everytime. i'd fix it before it does ruin the cases.

[TRX-330]

yep it is wore ou and just bought 2 new sprokets along with a did chain. so i hope ill be good to go.

[bwamos]

Make sure you have enough slack in the chain. Sounds like you are tightening the chain too much. When the suspension compresses, the chain gets tighter. So if it's already tight it is forced to strecth.

If it is rubbing on your case you may be getting so much force that it is forcing your countershaft to flex.

You should have about 1"+/- up down movement on the chain mid span w/ the quad just sitting on the ground w/ nobody on it.

Once you set it compress the rear suspension making sure that the chain never get's completely tightened. Just short of it at the tightest location. You want no tension stress on the front/rear sprockets under compression. It will destroy things as you have experienced.

[dork]

listen to bmwamos, i've seen countershaft splines stripped because of a too tight chain.

[bigsam]

i have a 250x frame with a 350x motor in it the motor was built by fourstroke tech before i got it and what i know that it has is an aftermarket cam, the guy claimed it is bored to a 530, a high compression piston and that is all i know of for engine parts done to it but ik there are more than that cuz it hit 81 at the local ice drags but it is a pain in the @$$ to kick over in the winter


ps i only paid 800 for it and it runs great and has new plastics and the guy i got it from has another 250x frame with the 350x motor in it for i think 600 but not positive on that but that doesnt have the same mods as mine