First Post, Need Help

[pccusnretired]

Hate to start off with my first post asking for help, but got in over my head today when trying to replace the impeller on my 1985 Yamaha 90 HP. In trying to remove the lower unit one of the bolts snapped off. I managed to drill through the broken bolt enough that I could try a bolt extractor to remove the piece that was remaining. This also broke off. I managed to knock the part that broke off the extractor through what was left of the bolt. I ended up cutting threads for a 1/4" bolt in what was left of the bolt. I spray a lot of WD-40 up through the bolt before trying the extractor and it still wouldn't budge. Should I take it to a machine shop to see if they can remove it or is there something else I can try to get the remaining piece of the broken bolt. If I can get it out, is a 1/4" bolt plus the other 3 going to be sufficient to secure the lower unit. I've only had the boat out twice and it was overheating at low speed and very little water coming from the pee hole. Any help is greatly appreciated.

[captainaksee]

heat is your friend, and use a good penetrating oil like Kroil or even pb blaster heat it hot, with an IR temp probe monitor the temp as to not melt your alum.
then use your easy out, with some time you should be able to get the broken bolt out. I do not advise using a 1/4" bolt replacement. If the threads get damaged you can use a helicoil or Loctite Form-A-Thread is a great product that you can use to repair the threads.
good luck

[pccusnretired]

Thanks! Sounds like this may be beyond my skill level. I am going to look for a machine shop that has the proper tools to remove the broken bolt. Any idea where one might find a lower unit for this motor at a good price?

[rodbolt17]

NEVER EVER EVER use an easy out.

DO use oxygen/acetylyne.

once they break the only good alternative is to simply drill and retap or drill and heli-coil.

usually stuck bolts are simply due to lack of maint.

[boscoe99]

NEVER EVER EVER use an easy out.

DO use oxygen/acetylyne.

once they break the only good alternative is to simply drill and retap or drill and heli-coil.

usually stuck bolts are simply due to lack of maint.

Is that an oxymoron or what? Like military intelligence.

An easy out is almost never easy. In my experience they only make stuff worse.

Folks don't want to do maintenance on a product that is operated infrequently, at high loads, usually on crap gasoline, in a very harsh environment, but then wonder why stuff goes wrong.

Maintenance is not a four letter word. The more maintenance that gets done the better the product turns out to be.

[pccusnretired]

NEVER EVER EVER use an easy out.

DO use oxygen/acetylyne.

once they break the only good alternative is to simply drill and retap or drill and heli-coil.

usually stuck bolts are simply due to lack of maint.

From the looks of the impeller it wouldn't surprise me if the lower unit had never been removed. There were big chunks of rubber underneath it when we removed it. Water flow still appears to be weak from pee hole so there may be some pieces of old impeller blocking flow somewhere. The bottom of the lower unit looks like it was broken off and reshaped. Had I known what I know now I would have never paid what I did for this boat. I was told everything was in working order. So far the only problem I haven't had was it sinking and not sure that was a good thing. Thanks for your help.