engine mounts

[Navman]

Hello again. I resolved my issues with the fuel pump. I replaced the pump, not the issue, checked the filter housing, not the issue then replaced the fuel lines with flex and problem solved. Thank you to all who contributed. NOW I have discovered a loose lag bolt on my starboard engine mount. After investigation I found that the fiberglass encased bed-logs are wood core. The lag has stripped out. I have bought a longer lag but it is not catching. I also bought a longer and wider lag but will have to drill the mounting flange hole to fit and am afraid that the reduction is surface area will adversely affect the integrity of the flange. Not to mention there are no guaranties that the new lag won't strip also. I have thought about filling with epoxy and micro fiber then drilling it out, but how would that work with a Lag bolt. I am thinking I may need to drill and tap to accept a machine bolt. Any suggestions?? I am hoping it's going to be a long mild winter because the list keeps getting longer each time I complete a task.

Thanks!!!

 

[frick]

Sound like a reasonable plan

Hello again. I resolved my issues with the fuel pump. I replaced the pump, not the issue, checked the filter housing, not the issue then replaced the fuel lines with flex and problem solved. Thank you to all who contributed. NOW I have discovered a loose lag bolt on my starboard engine mount. After investigation I found that the fiberglass encased bed-logs are wood core. The lag has stripped out. I have bought a longer lag but it is not catching. I also bought a longer and wider lag but will have to drill the mounting flange hole to fit and am afraid that the reduction is surface area will adversely affect the integrity of the flange. Not to mention there are no guaranties that the new lag won't strip also. I have thought about filling with epoxy and micro fiber then drilling it out, but how would that work with a Lag bolt. I am thinking I may need to drill and tap to accept a machine bolt. Any suggestions?? I am hoping it's going to be a long mild winter because the list keeps getting longer each time I complete a task.

Thanks!!!

If the wood is getting "soft" I will soak in "Get Rot" beforehand.

Rick+

 

[Loren Beach]

Unless there has been some loose water in the engine compartment and actual water has gotten into the encapsulated wood bed log, the problem is likely to be just time and entropy.
I suspect that the lag bolt loosened up a tiny bit over the years and vibration from the engine just made the problem worse. Finally the threads have crushed out the wood fibers enough that there's nothing left to grab onto.

If you do not solve it with a larger lag, the gold-standard method is indeed to over drill, fill with thickened epoxy and redrill. I would imagine that getting to the holes will be challenging -- probably have to take that mount out while supporting the engine on that side. Then do both holes while you are in there.

I recall reading about someone driving in a new lag coated with wax into wet epoxy. After curing they backed it out and reassembled with the mount. I have not tried this myself, however.

"Just one more thing!"
Lastly, do a careful alignment of the engine to try to minimize vibration and movement that exacerbates this problem in the first place.
(If / when the boat is in the yard, check the shaft for true-ness as well. Balance the prop. We have been through a lot of this stuff in the last two decades, getting vibration out of the drivetrain.
If you read Mainesail's fine site, he dwells a lot on alignment of the engine.

FWIW, about every five years or so, I find that I can take up a little bit on a couple of our mount bolts.

Regards,
Loren

 

[Navman]

emgine mounts

Thanks Lauren, as always you and the other contributors have good suggestions. I had thought about coating the bolt in wax, filling the hole with thickened epoxy and microfiber and then dropping the lag in. Then backing it out after its cured, cleaning it, inserting it and then tightening up. Just wasn't sure if anyone else had tried. I do believe there was water in the boat at one time as there is a water line about 1" up on the furniture above the sole ( another project for another year is getting rid of the water mark). The other bolts and mounts seem ok. I think if I had to I could get a right angle drill in there without removing anything if I had to enlarge the hole as it is the forward hole.

 

[Timsb]

I have the same problem on my 32-3. Luckily it is only one bolt and I can get a drill on it. I drilled the hole to 5/8 and filled it with thickened epoxy. At the suggestion of tech support at west systems I used Gflex-650. I haven't drilled the pilot for the lag or tried tightening the new lag yet. The epoxy is stronger than the wood, I just hope it will compress enough for the lag to get some bite. You will need some warm weather for the epoxy to harden properly.

If this doesn't work I'm thinking of taking a stainless steel plate welding some machine nuts on the bottom, recessing the stringer to accommodate them and lagging the plate to the stringer. Then bolt the mounts to the plate.

At least it's great opportunity to change the mounts and align the shaft.

There's a good thread here that Loren pointed me too a few weeks back:

http://www.ericsonyachts.org/infoex...holes-in-engine-mount-stringers&referrerid=28

 

[Navman]

Sorry for the misspell on your name Loren. My bad.

 

[lindaloo]

Fill and drill

Tim mentions

"the epoxy is stronger than the wood"

Having never done this procedure myself, is there a problem with drilling the epoxy ? Does the drill bit have a tendency to run out into the softer surrounding wood ?

Could you insert a wooden dowel into the hole when you fill it with the epoxy. Subsequent drilling out would be simple and correct alignment.

(Dowel diameter less than lag bolt of course !)

Rob

 

[blueox]

motor mounts

My lag bolts wouldn't tighten on my e34,I raised the engine marked location of mounts on beds,overdrilled holes with hole saw,lightly sprayed new bolts with pam cooking oil, placed bolts thru mounts put them in place and after I was able to back lags out and tighten without any trouble.Also on the forward mount I was able to thru bolt with a backing plate. It was a scary roll of the dice but seems to be ok. On a side note I raised the engine with a small chain fall with a two by four over entrance to boat. Good luck Mike forgot to say I filled holes with west thickened epoxy

 

[Timsb]

I read about one other fix somewhere in my searches. Use a hole saw to cut a plug out of good wood, then use the next size smaller hole saw to remove the bad section of stringer using the old lag hole as the pilot. Then epoxy the plug in place and drill to accept a new lag.