Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 M3W engine vibration

My 2012 M3W developed a severe vibration on pulling away and slowing down. The vibration shakes the car and is accompanied by a squeaking of rubber on metal type of noise. I suspected that the centa drive was on the way out and my local dealer has fitted a Bleazey conversion. When I picked the car up from the dealer, everything seemed perfect and the transmission felt so much better. But after a few miles the vibration and noise returned.
After a bit of experimentation, I realised that the vibration is purely engine related ie it happens when the car is at a standstill as well as in motion and is between approximately 1100 and 1800 revs. It also occurs independently of the clutch being engaged, or being in gear. When driving, the same problem is experienced as the engine speed drops into this range. However, it does not seem to happen when the engine is cold.
Any ideas would be much appreciated. I really hope that the engine doesn't have to come out again.
PS My dealer commented on the top quality of Phil Bleazey's parts. And his service in getting the parts delivered to me was fantastic! Thanks Phil.

Have you checked that your spark plug caps aren't loose? This is a common problem and does induce rough running. Just use a dab of loctite on the threads to stop the caps from shaking loose.

Edit - I've just re-read your post and it does sound pretty severe so probably more than just loose plug caps! Having said that, there's no harm in dealing with them anyway.

Have you checked exhaust mounts or engine mounts?
Just the comment about all is okay when its cold. Exhaust mounts easy enough to check, engine mounts not sure how you would check in situ other than visual - we have a 2012 car in at moment with engine out and the mounts do seem a bit more flexible than normal even when cold.

Mine has an occasional engine "rattle" phase - I just assumed it was some bad harmonics somewhere in the engine as it happens despite engaging the clutch, and happened pre as well as post Bleazeyed.

A real good look at the engine mounts and weld points is merited.

A good look at the metalastic engine mounts, they do disbond and sag. As your car is a 2012 one, have a close look at the chassis for cracks, particularly the upper tubes just behind the rear upper wishbone mounts, as detailed in the Buyers Guide in the Owners Resource at the tip of this forum. Just to be on the safe side.

Had the same trouble with a very rough running engine below 1800 rpm.
Found at first a loose spark plug cap and secondly a loose spark plug.
Put new spark plugs in and everything was back to normal.
I’m happy again!
Good luck!

would this be a sign the HD cush drive it going? or do you have the centa upgrade? Is the cush drive always turning with crank whether the clutch is engaged or not? If so, it might be the compensator

When the H-D compensator goes it sounds like a large can with aluminum balls rattling around. Other symptom is that the car won't go. The cush drive is AFTER the clutch so it will stop spinning when the clutch is depressed.

You mean BEFORE... see https://www.mtwc.co.uk/wp-content/uploads/2018/04/M3W-Parts-Book-V5.2.compressed.pdf (or take a look when you take the engine out! ).
The cush stops turning when you turn the engine off. If you think about it, you dont want the torque spikes hitting the clutch so it makes sense to put the cush next to the engine output shaft...