Engine Mount

Has anyone here ever had there top engine mount brake?Mine has broken 2 times and I don't no why!

Yeah mine were broke when I pulled my engine the other day. I am going to make my own replacements because the stock ones look really flimsy and they obviously don't work too well.

Maybe it was because I was going off some jumps

Just going off jumps in itself wouldn't break a motor mount as far as I know. If you were landing hard and bottoming out, or if your frame is cracked or twisted then jumping could be a culprit of the mount breaking.

If it is a common problem on these quads, which it sounds like it might be, then it could be a vibration issue that yamaha overlooked. What year quad do you have? Mine is an 87. It could be a problem on the earlier models that they fixed later. I work on this type of stuff almost weekly at work. Basically, the natural frequency of the guard could be near an engine speed which would cause it to fail. I am going to check and see if they changed the part number for later years later today and get back to you.

The part # doesn't change through the years but that doesn't mean that they didn't change it while in production and made the change apply to all previous models. I would suggest welding your old mounts back together and gusseting them (if you can). Otherwise, go buy some new ones from the dealer

The mounts arent to expensive you are in luck!

Check to make sure all your motor bolts are tight, the ones that hold the enging in the frame. If you had one that was loose then it would cause the motor to move and shift breaking the mounts on top.

Well the bolts that are attached to the bottom of the engine are double bolted instead of stock bolts.Could that alos be a problem?

P.S. mines a 1999

And Plus the jumps that I went off had no landing,they were just the jump.Could this also be a problem?

I dunno I hit jumps like that a lot & have no problem yet with my mounts breaking.

yea i dont think its from jumping it cause most of my jumps have no real landing and i dont have any problems like that

ok thanks.