250X cam in a 300EX?????

[swamprider7]

I heard that the 250X has a hotter cam than the 300ex. Is this true? If so, can you put a 250x cam in a 300ex? Has anyone done this? Is it worth it? Thanks in advance.

[Predator36]

The after market companies make the same cam for either engine. and yes it will fit.

[wilkin250r]

The stock 250x is slightly hotter than the stock 300EX, but any aftermarket is going to be the same for both. And yes, you CAN replace it, but I don't think it is worth it.

By the time you tear apart your engine, replace the rings, gaskets, possibly the piston, you're better of just spending the extra hundred and getting an aftermarket cam, you'll see much better results.

[redrider ex]

yes it is a hotter cam and yes it will fit i have one in my 300ex and it gave mine a better trottle responce and a little more top end .
I have a extra 250x cam if you want one

[swamprider7]

Thanks. I thought that it probably wasn't worth doing. I thought it would be kinda like the xr400 and 400ex cam swap. And correct me if i'm wrong, but it is not necessary to replace the piston and rings when you change a cam. If you are just changing a cam, you only have to replace a head gasket. Thanks again for the replies.

[redrider ex]

you don't have to even take off the head or change the head gasket you just take off the valve cover or some call it the rocker cover.

[swamprider7]

your right. duh.....i knew that. The last time i changed a cam was 2 years ago. It was in an xr80. The leading edge of the cam lobes were all worn so bad that the trailing edge of the cam lobes made a very steep point. Its hard to explain but the cam lobes were all out of whack. The rocker arms would actually make a loud "click" sound when the passed the top of the cam lobe. Thanks for pointing out my mistake.

[redrider ex]

allways glad to help:D

[wilkin250r]

My apologies, I assumed that you would be doing a complete top-end rebuild if you are replacing the cam.

True, you do not need to replace the rings or gaskets when only replacing the cam. Also, with the 250X cam, you will not need to hardface your rocker arms, saving you a bit more money.