Broken Engine mounts: 2011 EC300 :(

fenwickwick

fenwickwick

New member
A couple weeks ago I noticed a gnarly vibration on the bike. After doing some investigation I noticed that the two engine mounts going from the head of the motor to the frame (right by the radiators) were snapped right at the bolts. So to cut down on the vibration I got two big washers and put them behind the bolts to clamp the engine mount to the frame. It worked great until two days ago the same engine mounts end up snapping again, but on the side where they attach to the actual motor this time. So now I have two engine mounts broken on both sides....

Has anyone had similar problems? The mounts are made of aluminum so it was not a surprise to see that they had both broken.

I guess my question would to you guys would be should I fabricate new mounts out of a better material, or just order new ones?

I will upload pics to show exactly what I am talking about whenever I get the chance.
 
I would suggest loosening each engine mount bolt before you fab anything up to replace the broken mounts. It could be a matter of uneven torque/installation of the other bolts, or even a misalignment of mount holes on the rest of the frame. Loosen the swingarm bolt too, just to let the engine float. Then fab something up to replace the mounts.

Would love to see pictures as I have an '11, and if there is something I can do to prevent an occurrence.
 
I'd like to remove the head braces from my 2010 model (same frame) and see what that does for vibration. The 2012+ models don't use them and are noticably less vibey.
 
pscook said:
I would suggest loosening each engine mount bolt before you fab anything up to replace the broken mounts. It could be a matter of uneven torque/installation of the other bolts, or even a misalignment of mount holes on the rest of the frame. Loosen the swingarm bolt too, just to let the engine float. Then fab something up to replace the mounts.

Would love to see pictures as I have an '11, and if there is something I can do to prevent an occurrence.
Click to expand...

+1 on this....I would bet the engine is in slight (or bigger) twist OR one or more of the other mounts are loose. That will put more load on the aluminum stays and they become the weak point. I had an '04 that I bought with a broken stay- replaced it with an OEM one, did the above procedure and it is still working to this day.....over a year. Nothing wrong with the OEM part IMO Yet to have an issue with my '10
 
fenwickwick said:
A couple weeks ago I noticed a gnarly vibration on the bike. After doing some investigation I noticed that the two engine mounts going from the head of the motor to the frame (right by the radiators) were snapped right at the bolts. So to cut down on the vibration I got two big washers and put them behind the bolts to clamp the engine mount to the frame. It worked great until two days ago the same engine mounts end up snapping again, but on the side where they attach to the actual motor this time. So now I have two engine mounts broken on both sides....

Has anyone had similar problems? The mounts are made of aluminum so it was not a surprise to see that they had both broken.

I guess my question would to you guys would be should I fabricate new mounts out of a better material, or just order new ones?

I will upload pics to show exactly what I am talking about whenever I get the chance.
Click to expand...

I have nothing to add to this thread, other than I like your avatar? Is that an LVS(R)???
 
Rick said:
That must be the Army version of the USMC LVS self-loader variant (MK48/18A1)

Cool...thanks

If your serving, thanks for your service:D
Click to expand...

No problemo! And the Marines use the PLS, which is the same thing with another axle in the back

Sent from my SCH-I545 using Tapatalk
 
fenwickwick said:
No problemo! And the Marines use the PLS, which is the same thing with another axle in the back

Sent from my SCH-I545 using Tapatalk
Click to expand...

Sorry.....didn't mean to throw a wrench in your spokes...... the LVS was during my era in the Corps.
Carry on! I'm done.
 
yep same here, did my topend last winter and both head stays were snapped at the head.

turns out ALL my motor mounts were loose. Like a full turn or two on each bolt/nut going under the engine. Wow.

Tried to fab my own aluminum and steel, someone told me to NOT use steel, if something needs to give (ie break) then it should be the stays, not the head. Good point.

Ended up getting them from Mark at Gofasters. Perfect fit. Not expensive.

Still intact 1 year later. So now I keep the motor mounts tight. They should be a regularly checked maintenance item.

I've heard of some riders leaving broken head stays off. Anyone else done that?
 
Ok, Ended up fabricating my own. I made sure to elongate the holes for a little bit of play. Bike feels great now. I'll be checking my mounts regularly now!!
 
UPDATE: Couple months later and the vibrations are back with a vengeance. This time all the engine mounts are tight. Could this be a crank problem? Flywheel? Its like riding a jackhammer on wheels. The vibration goes away for the most part when you are in gear and begin to let out the clutch, that points me in the flywheel direction.
 
I apologise for jumping in late but, I have my 2011 300 apart right now and replaced my head stays with fabricated pieces I made from .125" stainless. Mine weren't broken I just think the stock aluminum pieces are way to thin adding to the vibration problem. Should be up and running shortly, I'll let you know if the vibration is reduced.
 
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