Cr250 Engine swapped 400ex

[@simssimms6522]

I'm putting a rm125 in my nacs racing 400ex I have a vid up if interested. I had a 212cc pit bike race engine in it like 21hp lol but now I'm going to mod the frame to share my m125 dirt bikes engine since I don't have the cash to buy a separate engine at the moment. Only mid 30s hp but that's fine with me it's cool as hell being 2 stroke and 125 is still not slow if you just want enjoyment. Years ago I had a different nacs racing 400ex I put a yz426 engine in it built by east coast atv that thing ripped 55hp it was to much power on the mx track actually made me slower because the power was so unforgiving.

[@lixardy8675]

Do you know where I can purchase a motor like that or similar?

[@denzelderksen7564]

I've seen 250 two stroke engines on eBay. I got mine from a cr250 bike that I bought.

[@lixardy8675]

Denzel Derksen oh ok thank you 👍🏼

[@jumpingjerh9582]

yesssssss.

[@50nick83]

How hard was the swap?

[@denzelderksen7564]

@@50nick83 not too hard, just had to make sure the chain lines up and the pipe had room

[@bobbyhill789]

What kickstarter is that?

[@denzelderksen7564]

It’s the original 1988 cr250 Kickstarter that came with the motor. I just had a welding shop cut and reweld it so it fits with the frame.

[@ronaldtartaglia4459]

Dude if you haven’t already, check out John langman. His swap is unbelievable.

[@joeb6318]

What pipe did you use?

[@denzelderksen7564]

Oem pipe from 1988. It has a mid sized dent in it

[@joeb6318]

@@denzelderksen7564 from a 88 cr bike or the 250r wheeler? Looks like the bike?

[@denzelderksen7564]

Yep from a 88 cr250. The bike was in pretty rough shape, so I didn’t feel bad about doing the swap

[@joeb6318]

@@denzelderksen7564 ok thankyou. I have a 96 cr engine that I think I'm gonna drop in a ex chassis. What about the radiator? What did you use there? Also could you not get the airbox to work?

[@denzelderksen7564]

I got the radiator off eBay for about $70. I believe it was for a Yamaha raptor or a yfz450. I just zip tied it onto the frame. I couldn’t get the air box to work without cutting it. The air filter I have on it is also from eBay. I just measured the carb intake width and ordered a filter accordingly.