CRF450 engine Problems

[Ex_Rider43]

Did you got any engine problems with your crf engine??? what should I look for when I do the conversion??

What is the trickiest part and why.

[Ex_Rider43]

anybody???

[NacsRacing400]

I have had zero problems with my engine and i raced all year with only 1 piston change. This is with a tc motor also so i would have to say that a stock one would hold up like a tank. They are a race motor though so you really have to keep the jetting right and make sure everything is tight and functioning or it will lead to a expensive blown motor. Also the oil needs to be changed after every race because it only holds alittle bit and the oil breaks down fast. Thats about all that really is any different than any other motor. Everything else is the same, air filters, use the clutch, ect.

[Ex_Rider43]

ok and did you use a stock 400ex frame or you bought a aftermarket one for the motor?

If you used a 400ex frame, what is tough to do when you are building it, motormounts?? radiator?? I also heard about the swingarm not fitting right ...:confused:

If im not mistaken, they make all of those parts so u can bolt it up into your ex frame. Contact outlawex i think he did the conversion.

[Ex_Rider43]

I remember that outlaw did the yzf426 conversion

[Tommy 17]

his is in a herrmann chassis....



only problme i hear about the crf motor is they have to change the oil constantly in them....

[ZRider400]

some of the early 02's had valve problems.

i have also heard of water pump seal problems.

my old 02, had no valve problems.....but did have the water pump seals go.

[Ex_Rider43]

ok seems like a good motor.

where can I get some good tips on doing the conversion??

[BSTURDIVANT]

It's a pretty big job getting the engine far enough to the left to line up the sprockets I milled about 1/8' off the left side of the engine where the swing arm bolt goes thru and made new inserts
to go in the engine with the smaller 400EX size hole for the bolt.
you also have to modify the spacers that go thru the swingarm.

Really not to hard to install in 400 frame!

[atvrida]

THIS IS KIND OF A STUPID QUESTION BUT US THERE ANY POSSIBLE WAY THAT A CRF 450 ENGINE WOULD FIT INTO A 300 EX FRAME?