K50 Mounts to K75 Mounts

sailr4 · August 29, 2016, 07:07:05 AM

I have read just about every engine mount thread I can find, but I have not found this answer. If I need to switch the rear mounts to K75's (K50's all around now), do I need to loosen the front mounts to raise the rear of the engine?

Rob

britinusa · August 29, 2016, 07:16:31 AM

I would say !YES!

The engine should sit close to the lower end of the mounting studs, so you'll probably have to raise the engine by about 2"

FYI I used a HF 1/4Ton (500lb) chain hoist to lift the engine single handed without any issues at all. Just be careful to not raise it such that you strain the control cables, might want to release their stress restraints further aft before lifting.

Also, I was able to release all the mounting studs and the mount securing lag bolts from in front front of the engine.

Use a caliper to measure the height of the mounting brackets on the engine before releasing the top mount stud nuts, this gives a good starting point after replacing the mounts.

And if you haven't purchased the mounts yet, contact Ken Kloeber.

Paul

Roland Gendreau · August 29, 2016, 10:13:06 AM

You might be able to do it without lifting the engine at all .

Back off the top and bottom nuts of one of the mounts - then, using a allen key, unscrew and remove the threaded shaft from the mount. Remove the lags holding the base of the mount. Then, having previously removed the threaded shaft of the K75, secure the base of the K75 to the boat with the lags. Insert the shaft through the bracket, screw on the bottom nut, then screw the shaft to the mount base. Adjust the nuts to about where they were. I would recommend you re-align the shaft after you complete the installation.

Ron Hill · August 29, 2016, 02:21:15 PM

Rob : If you are not getting the "tick tick" of the shaft touching the gland tube then don't change out the rear mounts and stick with K50 all the way around.

No, I didn't loosen the fronts when I went to K75s in the rear. I cut off the K50s with a Saws-all, took the K75s apart and mounted them that way after I removed the old K50s.

A thought

sailr4 · August 29, 2016, 03:42:29 PM

Thank you for the replys. I have only motored for 10 minutes to move boat from boat yard to slip. I did have quite a lot of "ticking" as I slowed to idle. I will do more "sea trial" before committing.

Noah · August 29, 2016, 05:42:27 PM

One man's "ticking" is another man's "knockin, "grinding", "rubbing", etc..... Lots of sounds and interpretations. Take it slow and really analyze the situation and don't try to figure it out underway. Tie the boat to the dock and run the engine in gear (in forward and reverse) straining against the dock lines.

sailr4 · September 03, 2016, 06:55:24 PM

Quote from: Roland Gendreau on August 29, 2016, 10:13:06 AM
You might be able to do it without lifting the engine at all .

Back off the top and bottom nuts of one of the mounts - then, using a allen key, unscrew and remove the threaded shaft from the mount. Remove the lags holding the base of the mount. Then, having previously removed the threaded shaft of the K75, secure the base of the K75 to the boat with the lags. Insert the shaft through the bracket, screw on the bottom nut, then screw the shaft to the mount base. Adjust the nuts to about where they were. I would recommend you re-align the shaft after you complete the installation.

What is the trick to unscrewing the threaded shaft? i can't get them to move (mounted 50's or unmounted 75's)

Indian Falls · September 04, 2016, 06:10:15 AM

I went through all this already too. http://c34.org/bbs/index.php/topic,6386.0.html
I did not disconnect the prop shaft or the exhaust. I did not move the engine. I removed the old mounts with a saw and installed the new ones one at a time. I would not go with vetus 50's and 75's go with all the same, the hardest ones, not the softer ones. Keep shaft alignment in the back of your mind. You may need lateral adjustment, without enlarging the mount holes you could limit side adjustment you may need.
Make sure you comb the whole forum, there is lots of info concerning motor mounts.

Noah · September 04, 2016, 11:06:41 AM

[You may need lateral adjustment, without enlarging the mount holes you could limit side adjustment you may need]

Can you please elaborate a bit more on this? Did you drill new holes in stringer or elongate existing holes or did they fit in existing holes?

Ron Hill · September 04, 2016, 12:22:55 PM

All : Most of us have had to elongate one or both of the Vetus mounting foot holes. Seems the factory didn't take care to drill the original holes to the center of the old engine mount holes.

Much easier done than fill the old holes and drilling new mounting holes.

A thought

Roland Gendreau · September 07, 2016, 06:29:23 PM

Bob

When I removed the shafts of the K75's, I clamped the base of each in a vice and used an allan wrench on the shaft to remove it. The threads have thread locking compound on them so it takes a good amount of torque to break it free.

Indian Falls · September 12, 2016, 05:47:18 PM

Yes, elongate the mount holes in the base. I had to take mine out again after putting all four in and then discovering I could not move the engine sideways the .020'' needed to get that .003'' alignment on the shaft coupling. Filling the old holes and redrilling was not a possibility without removing the engine from the boat.
My mounts did not come assembled. The fact that they were separate made the replacment job easy so to speak. IF they were like the old mounts you would have to move the engine, disconnect everything ect ect...