Motor Vibration On Typhoon

[Jim]

My 3.5 Nisson Motor and boat Vibrate when running at low speed, after speeding up the vibration goes away. It sounds like part of the vibration is in the Spartan Bronze motor mount but also the whole boat vibrates. Also when the motor is turned around backwards for reverse, the motor wants to lift up and since the mount is not fastened down it tries to kick-up. I have not had the boat long, is this normal for these small motors and normal for th mount to try to kick-up in reverse or do I need to trim the angle of the motor.

[sloopjohnl]

can't speak for a motor that has to be turned around for reverse, only had one and got rid of that with the previous boat. but your vibration may be coming from an unbalanced prop or a vibrating prop due to a loose connection or bad bearings. i've run a 6hp on my typhoon for ten years now without any strange vibrations.

[Bill Bloxham]

My 3.5 Nisson Motor vibrates a lot at low engine speed, too. It only has 1 cylinder, and its' inherently unbalnced.

I had a two cyl. 6 hp Johnson for a few years and it, like sloopjohnl's, was smooth at low speeds.
Try pinning the mount down with some quick release system by the transom if the engine lifting is a problem. The best reason for your type of mount is to be able to stow the engine below to balance the boat while under sail. You spend very little time with the engine reversed.



mmmmmmbill@aol.com

[brent musolf]

jim,

Had a typhoon and had the same problems. I think it has more to do with the engie design than anything else. I put a piece of closed cell foam between the engine bracket and the hull where it contacted and that eliminated most of the vibation. You can also put weather striping under the cockpit seats where they rest on the hull so they will not vibrate as well.

Good Luck

Dr. B



sailcovers@usa.com

[Bill Bloxham]

Dr. B:
How thick was that closed cell foam?

Bill



mmmmmmbill@aol.com