Breaking front factory motor mounts?

[toby400ex]

For some reason I'm having problems with breaking the front factory motor mounts on my YFZ. Every race another mount breaks around the eyelet where the bolt runs through them on the motor. I admit that the quad gets abused, but why are the mounts breaking? Is there a solution. I'm pretty sure all of the other mounts are fine but I'm going to double check.

[csr250r]

is it like a hairline crack on the upper part of them?

[toby400ex]

Originally posted by csr250r
is it like a hairline crack on the upper part of them? Nah, theyre broken completely. I pull the bolt out and the top of the mounts will fall apart. Ive gotta check the lower mount to see if it is loose. I made this thread too soon without searching.....:rolleyes:

[gtilley45]

Yeah, make sure all your other motor mounts are tight. Especially the one that bolts to the head. Me and a friend of mine were both breaking the front motor mounts and come to find out we both had other mounts that were loose.

[Ride1Rob]

They're breaking because they're too tight. You have to tighten them to torque specs or either they'll break(Too tight), or vibrate loose(Too loose). I went through three sets before I realized this.

[mx1791]

ive got this problem too. glad this thread is here, im gunna check all my other motor mounts to see if there loose.

[daddio]

Check the bushings in the engine cases where the swingarm pivot goes through. I went through 3 sets of front motor mounts, then realized that those bushings were wore out.
I replaced the bushings, and have not broken another mount.

[Ryan]

Originally posted by Ride1Rob
They're breaking because they're too tight. You have to tighten them to torque specs or either they'll break(Too tight), or vibrate loose(Too loose). I went through three sets before I realized this.

Good thing I seen this today. I just had to take one of the motor mounts off to get the oil cooler/tank off. I broke the damn drain bolt off in the tank. Sad thing is I seen it comming.

I'll make sure to torque those bolts to the right specs when I get things fixed.

[400grl]

I was having this same problem - due to the bolt that goes through the bottom of the motor (I believe) that secures it to the frame being broken/loose - that caused the mounts to break from the excess vibration of the motor. Check ALL your mounts - I would recommend checking them every time you wash your quad.....just a good habit to get into.

[rooster300ex]

Yea check all other motor mounts. My 300ex's front motor mounts were breaking, because some other mounts were loose. I have recently put washers on all my mounts and hasn't happend since.

thats just the way they are....i broke soo many when i rode yfzs its because the frame flexs too much..take the bottom bolt out of the engine..might sounds crazy but it helps i also have some brandnew stock mounts for sale pm me if interested ill sell them cheap

[Ryan]

Anyone have the torque specs for the front motor mounts, and for the bolt that goes threw the front of the motor?

[toby400ex]

My lower mount was loose. The bolt was loose enough to spin by finger. Im hoping this also cures the small oil leak I have from the bottom of the motor, right where the mount is. Now I'm tackling the steering stem bearing, my honda was so much easier to work on:rolleyes:

[daddio]

If you still have the leak, permatex makes a product called "the right stuff". Clean the area where it leaks, and smear this stuff on it. It will hold until you have to split the cases for a rebuild.

Try working on a LTR....... Then the YFZ will seem like a piece of cake. :D