9.8hp powerhead stuck

[britabroad]

Hi, I have a Mercury 180cc sailpower (basically a Merc 9.8 with an extra long shaft - 1985 I believe).

I'm trying to get the powerhead off, so that I can get at the exhaust plate bolts (which have broken off), so that I can change the exhaust plate gasket and stop my bottom cylinder from getting wet.... phew a real mission!

I have removed the 6 power head nuts from beneath the bottom cowling (horribly corroded) but the powerhead will not budge. Is there anything else I need to remove? Do I need to drop the lower unit first?

Many thanks in advance.

 

[emckelvy]

Re: 9.8hp powerhead stuck

Sounds like a Salty Dog! You might try pulling the lower unit but as a warning, if it doesn't come down freely, the driveshaft may be stuck in the crankshaft.

In that case, don't bang a lot on the gearcase as you'll start breaking stuff. Try using metal machinist's wedges (if you can find some). Plastic or wooden wedges would do in a pinch, as would the thin, wide blade of a "Wonder Bar".

If it seems like the front of the lower unit is stuck, use heat from a propane or MAPP torch on the long stud running up the front of the gearcase. These usually get stuck from salt deposits.

On the powerhead, try prying against the front (2) studs (one on each side) as you can get some leverage there to help bust the powerhead loose. Make sure a nut is on each stud so you don't damage the threads.

Last resort, turn the motor upside down and soak each stud with PB Blaster (a very powerful penetrant) or Liquid Wrench if you can't find PB (my local Wal-Mart carries PB).

After soaking for hours or better overnight, apply heat and see if that helps bust it loose.

Too bad Merc didn't put a bit of anti-corrosion grease (or a thin coating of Permatex No. 3 gasket dressing) on all these studs/bolts, they'd come right off! But that would've cost another $.25 and we can't have that, eh?!!

HTH & G'luck with the disassembly........ed

 

[britabroad]

Re: 9.8hp powerhead stuck

Thanks for the help - removed the powerhead by pulling the lower unit and then inverting the rest and soaking the studs in PB blaster, with a gentle tap on the studs every hour or so. Worked a charm.