Q? Will a 450 motor fit into the frame....

[steves389]

Hi guys,

I hope someone has tried this and can offer me some help. The 2002 CRF 450 motor is nearing completion and before pre-assembling the motor I wanted to know if it will fit in the frame or does the top end have to be put in while its in the frame. Anyone know if the entire motor will fit before I waste the time? (Stock 2002 CRF Frame and motor)

Thanks for any help - Steve

[E-WA]

It will go in in one piece, but you may have to leave the valve vcover off. Also it is quite the biatch, to get out , so going back in will be even worse 😢 I have the same problem coming soon, I must reinstall my motor into the frame. 😢

[Throttlejockey]

When I put my 250 motor back in I left the head off and it slipped right in.

I suggest you leave the head off.

[steves389]

Thanks guys.

Anyone else tried it?

thanks again.... Steve

[samurai41]

you can put in all together, put the front in first and then lift front up between frame rails and swing the rear in and pivot front down. i've down it about 6 times in the last month on three bikes. once you know it's hard to forget. unless you don't do it for awhile (practice makes perfect)

[chomp]

i had a hard time pulling the engine out of the chasis too. I tilt it to the side and remove the uni cam cover. Slide out after a few attempts. I'm hoping it'll be easier to put back.

[davevaliket]

If you are building the bike from scratch, most of the time it is easier to put the frame on the motor vs. putting the motor in the frame. Frames are lighter so its easier to work them into position until you can slip the bolts into place.

[rallendude]

If you know how it goes right in. No problems. Motor has to go in from the right side. It can be done with the valve cover on. You gain a lot of play room if you remove the valve cover and the cam sprocket. Just the valve cover doesn't help that much.

I believe you have to put the engine in facing to the left and when the valve cover is up between the spars rotate the back into the frame. Make sure the engine is all the way up as high as it will go. Rotate it in and lower it down.

Oh yeah, it will help if you remove the coolant elbow from the front left of the head and the coil.