M25xp, convert from 3 point mount to 4?

[JSM]

Ian , Since my last post I have discovered that a lot of Catalina 34 owners with the M25XP have had great success with Vetus K75 mounts. The guys at Betamarine are also recommending AMC BRB 70 mounts which they use on all of their engines up to 30 hp.
I have a quote from Iso Flex and am still considering them but even with a 15% discount they are almost double the price of the Vetus K75.
All of these mounts are in the 50 to 55 durometer range and I have a feeling that any of them will be a vast improvement over the 3 Bushings Inc. mounts that I now have.
I need to pull the trigger soon as I would like to get this done before the weather turns.

 

[JSM]

Wish Me Luck

After a lot of mental anguish over the winter I finally settled on a configuration for the front engine bearers using 3" square x 1/4" thick steel tubing with angle iron "feet" welded to the sides. The rear mounts will sit on 1/8" steel plates that have nuts welded to the bottom side. The plates will be held in place with 4 lag bolts each.
Hoisted the engine up last week with a chain hoist ($30 thanks Craigslist!) put everything is place and got the coupling together fairly easily.
Will mark, drill and thru bolt the front bearers and lag the rear plates in this weekend.
Mount #5 will stay in place (with the nut backed off) as a backup until the boat splashes and sea trials are completed.

 

[JSM]

Success !

Happy to report that the operation was a complete success. Did a final alignment this past week and am totally pleased with the results. Engine operates smoothly at all rpms. Should be able to maintain alignment now that all 4 mounts are held in place with machine bolts.

The front mount was left in place as a fail-safe for the three hour trip from the yard to the harbor. Will be removing it soon.

 

[EGregerson]

3 point

Excellent! time for sailing

 

[bigd14]

I can finally file a preliminary report on the conversion from 3 to 4 point mounts. Overall the harsh vibrations from the motor turning over are gone. Very nice! I am getting some lower frequency vibrations probably from the engine needing alignment. Once I readjust the alignment, I will report back. But so far I am quite pleased with the results.