Sorry this time of year is busy getting everything set for the season, I’ll connect.
As far as engine noise goes I’m not sure what you did to the powerhead. I think you just dressed a clean one one did no mechanicals.
Good suggestion earlier on flywheel, you don’t have the flex plate style he was concerned about but make sure yours is torqued down.
Likewise the pawls, check the easy stuff first. Are you sure noise is not related to the lower unit? You could pull it and run a hose on the water pipe and see if noise persists.
For the not so easy suspects one thing to suspect is the ball bearing in the lower main cap, I’ve seen a lot of questionable ones even on the cleanest original powerhead. As a routine at a minimum, I remove all the covers and I split the case to give everything a good look over, you can tell a lot about true condition by checking ring spring back through both sets of ports, reed condition etc. Also any hints of corrosion can be seen, if everything looks good you don’t have to pull the crank train, clean originals do exist. However, the lower bearing ,end seals and Orings always get replaced. McMaster Carr has these bearings as it’s an industry size. I also steer away from bearings made with plastic cages, I see that frequently on original 70’s powerheads. Obviously the case gets resealed and new gaskets go in.
Oddly the flywheel end cap bearings are usually just fine, they are bigger and they are not near the cooling water discharge like the lowers
so maybe that’s why, don’t know, I just always replace the lower one.
I’ve never seen internal crank related roller bearing issues on clean powerheads but, of course this is always a possibility particularly if corrosion formed on anything internal if storage was less than ideal. Any hints of corrosion on the rings, reeds, stops, crank weights and rods means everything comes apart to inspect the bearings even if rings all spring.
I hope it’s one of the easier suspects or not a funny noise at all, it’s hard to tell from the video, these motors are not quiet when running to accentuate odd sounds.
Be aware that the 90 cu in powerheads will bolt right on too, the 850/1000 ilk. You will just need to match it to the right carbs. So when hunting around you are not limited to the rarer 76 cu in the FGS version powerheads.
Finally got my ass in gear up here in the Holler and put some paint on this 61 Merc 800EL-1
Used Nasson single stage urethane with high build sanding primer over top of etching primer on finely blasted aluminium.
The lakes here in Northern IL are open now and I plan to get the motor in the water next week and see how it performs. Concerned with the noise I heard but want to make idle adjustments on the water and then run it and see what happens. The Merc manual states carbon buildup can cause noise so I got a can of Merc Tune and gonna blast and soak it and pray for a miracle.
Hey Randy aka 63g3,
Thanks for all the great info and recommendations. You know you should write a book.
I determined the rattle is not emanating from the lower unit or cowl. I had actually considered replacing the cap bearing, when I had it torn down, based on what I learned from Bob Grubb at OldMercs.
Looking great Terry. Sure you want to put it in the water?? Looks more like it should go in a show room.
Suggestion...Try running a tank of some Sea Foam mixed fuel to clean up carbon build-up before doing anything drastic. I've done that on just about all of my old motors. Usually find that after several days and a few hard runs the black crap stops dripping on my garage floor and some noise problems usually quiet down. Of course those are all OMCs and they usually drip black crap naturally
Don't mean this to sound like a commercial but never hurts to try. Now summer is here so get those boats on the water.
If the power trim rams motion when tilting up isn't stopped by a safety strap, the rams go fully extended, which results in the Merc can tilt over center (too far), and then when attempting to tilt down, the rams can't contract unless you manually give the beast a slight push.
The trim assembly can have just one solenoid for UP, and for DOWN the trim motor's large green can be wired directly to the small green (maybe green with a white tracer (stripe) since commonly there isn't enough load to require a solenoid for DOWN, with its relative large Red (battery positive).
I've seen lots of those trim systems with (2) solenoids too. One for UP and one for DOWN.
Terry, that's great that you got a 2nd. Good to hear the motor is running super and starting right away. Don't know anything about the Merc t/t but doc knows what he's talking about. As an aside the t/t on my '76 85hp OMC does not have any solenoids for up or down. It grounds through the engine hookup, has a heavy red from the batt to the rocker switch, one heavy green (up) and one heavy blue (dn). I thought the PO hot wired it but after research found out that was correct.
Happy to hear you got Second! Your boat is a beauty. Still can't figure out what your rattle is, but as long as it keeps running that good I guess it's not important. When I get a chance I will go out and see how my trim is wired. I have one solenoid and it is controlled by 3 buttons. One for down, one for trim up, and push both trim and tilt to raise the motor all the way. We will have to get together again for a few more "Spotted Cows".
Terry, I was thinking that noise sounded a lot like when I lost a rod bearing on the crankshaft of my v6 Merc. If that is it, you should stop running that one to prevent further damage. There is a test you can perform in the garage that may help find if that is the problem. Pm me of call if you want to discuss further.
Use Seafoam Deep Creep. Did this my old Bayliner/Force 125. Went from falling off plane at 3000, down to still on plane 2500! But do as says here, BUT, bring extra plugs and a wrench as probably will foul a few more, crud breaking loose. And one can should be enough whole motor...
"Your intent is REMOVE the existing carbon buildup from the cylinders, heads, and rings, a spray decarb solvent product, such as SeaFoam Deep Creep, is needed. Some people use one can per cylinder.Run engine at fast idle, with engine running, slowly spray liberal amount into each carb, its gonna smoke up the place,spray for a couple minutes, now spray a larger amount into carbs until engine chokes out and stops,remove spark plugs and spray decarb liberally into each cylinder, install the spark plugs, let it soak for 2 to 10 hours. Start the engine and run at medium throttle, or if at the lake, run it at full throttle. It won't hurt to spray some more through the carbs. Run it for atleast 10 minutes to flush the crud out of your engine. Now remove and clean, or replace the spark plugs. It works well to do the spraying, the night before you go to the lake. This way you can let it soak overnight, and really flush it out at the lake.Don't do this in front of the garage door or the house, unless you want it coated with greasy crud.