Motor mounts

Sep 25, 2015
60
Catalina 30 Middle River
I am about to order 4 new motor mounts for my 1988 Catalina with the Universal M25 XP. Do I order the Vetus K 50 or the K 75? When I called Vetus they suggested the K 50s but what I read on here most said go with the K 75s. I am kinda confused and wondering what is the experience with one or the other? I have to change mine cause the one under the pump is very rusted. I think the pump was leaking at sum point and has been repaired. This is a new to me boat so any advice is very much appreciated.

Thanks
 
Sep 25, 2015
60
Catalina 30 Middle River
Ok I am confused as to why some would use K 75 rather than the K 50. Specs for the K 50. I think the motor and Transmission weigh in around 325Lbs . The Vetus rep said the K 50 is plenty for the weight. I am just wondering why someone would go with a larger mount. Second question is hump hose. 1.5/8" ID 6" length? I am going to place my order today so I want to be sure I am ordering the correct item. My boat is a 88 Cat 30 Universal M25XP. I am also thinking of replacing my exhaust riser with Schedule 80 black pipe since I have access to it free. Is there any issue with going back to the black pipe screw fittings?
Thank you so much for sharing your knowledge. I just bought the boat in Sept. This is my big winter project. Along with belts and hoses.
ADDITIONAL INFORMATION
Stiffness ratio - vertical 1
Stiffness ratio - athwartships 0,75
Stiffness ratio - fore and aft 2,5
Min. load (lbs) - static 56
Min. compression (inches) - static 0,079
Max. load (lbs) - static + dynamic 112
Max. compression (inches) - static + dynamic 0,16
Hardness in ° Shore 45
 
Dec 28, 2010
462
Catalina 380 san pedro
I just finished using all Stainless pipe to make a new riser for my Universal. Mine is unusual in that it is an M4-30. A bit of a beast in size so everything is custom. It cost me less than $100 in materials including the heat wrap. I'll post images when I can.
 
Sep 25, 2015
60
Catalina 30 Middle River
I wanted to follow up to help others that want to replace their engine mounts. my boat is a 88 / 30 with a Universal M25XP. You can see the mount on the left is trashed due to the raw water pump leaking on it. I purchased new Vetus K75 after much research on the web and listening to everyone opinions after they changed there mounts. I was going to go with the K 50s but the opinions of, they maybe a little to soft, and cause some movement that can cause some issues with the alignment where the shaft comes through the hull. It seems the K 75s are the ones to go with. Some mix the K50s in front and the K 75s in the back but I am not a fan of mixed as think they need to work together on all 4 corners.
Now the good part.. I read someone had changed their mounts without jacking up the engine and also did not disconnecting the shaft. I verified with Vetus in Hanover Maryland and they confirmed, you can remove the stud from the center of the mount. That will allow you to do each mount one at a time. Three mounts should hold the engine pretty close to its original since the motor is just sitting there static. Measure the height of all legs in Millimeters with a digital caliper and record them before you start. Next sawzall the old center bolt out and remove the entire mount. Un thread the center bolt of the new Vetus mount ( it wont be easy they lock tight the bolt in the mount so you will need a wrench and a good vise but it will un thread. Mount the base to the engine supports ( you might need shorter lags and you might need to slot the existing holes a little with a file). Next you should be able to put the thread rod stud of the engine foot. Add lock tight and thread it back into the base tighten down next bring your adjustment back up to the existing leg height and tighten down top and bottom. Recheck your height and move on to the next one and repeat for all 4. No lifting should be required and also no need to disconnect the coupling. I would recheck alignment after the boat is launched in the spring. I just ordered the parts and will report back after I get started to let everyone know how my plan works out.
 

dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
Damifudo- I replaced mine with the Vetus 75 also. I didn't think of sawing the old mounts out but I needed to fixed the stringers anyway so needed one side clear at a time. My old mounts were loose in the stringer due to soft wood. It might be difficult getting a sawzall in the engine compartment. It's not difficult removing the prop shaft coupler, well at least for me it wasn't.