250x to 350x conversion

[sjc115]

Can anybody give me some advice on installing a 350x motor in a 250x frame?

Specifically: Can I use the stock carb, wirning harness, cdi, and coil from the 250, or do I have to use the 350 parts for any or all of those?

Any tips or info you guys can give me would be greatly appreciated.

Steve

[wilkin250r]

I plan on doing the conversion, but I haven't done it yet. (In fact, my new 350X motor just got delivered last week) Here is what I have learned.

Have you checked out the Powroll kit for the conversion? http://powroll.safeshopper.com/78/cat78.htm?349

You WILL need the 350X CDI. I think the 350X carb is taller than the 250X carb, and will run into clearance problems. The 350x carb also doesn't have an accelerator pump, while the 250X carb does. Powroll recomends the 250X carb with the conversion, but I've heard of many people using Lectron carbs. I'm pretty sure the 250X carb is smaller than the 350X carb, so you could lose a little top end, but with MUCH better throttle response.

Personally, I'm going to fork out the bucks for the powroll kit, they seem to have everything spelled out and put together in one nice, easy package. The installation kit alone (without exhaust) is pretty cheap if you want to save money and weld the exhaust yourself.

[wilkin250r]

If you are using a complete 350X, I've heard that the rear-end swap is pretty simple, but there is no clear-cut kit for that like there is for the engine swap.

[beak7707]

I have a lectron carb off a 350x conversion if you are interested make an offer.

[01_300ex]

I have all of the stuff you need for the 350x conversion. Wiring harness, CDI, modified 400ex headpipe, 350x engine w/ kickstarter and shifter for sale. Pm me if you want anything.

[sjc115]

I think I am going to go with the powroll installation kit.

Has anybody used the powroll exhaust? Is it worth the $464?

01_300ex: Do you have any pictures of the pipe? How much do you want for the pipe and the CDI? (email me)

[01_300ex]

whats your email address.

[sjc115]

What about jetting?

If you are using a 250x carb, what jetting are you running?

[wilkin250r]

Originally posted by sjc115
What about jetting?

If you are using a 250x carb, what jetting are you running?

Powroll would probably have the answer to this question. Send them an email...

[Giz400ex]

For an exhaust, I would try DynoPort!! or Krank-it Racing! They can get you a 350x headpipe cheaper than Powroll!! My friend had them do it for almost half the price (i think?) But I know it wasn't that expensive.