Appreciate any help you can provide on the following:

1995 Tracker 21' Pontoon boat with 60 HP Mercury outboard (with oil
injection).
Summer of 2002 - Motor ran OK but periodically started to lose RPM's
while under way. I would be cruising at about 3000 RPM's and it would
suddenly drop down below 1000 RPM. If you played with the throttle,
it would resume normal speed and not show problem again for quite some
time (hours).
Winterized the boat in Fall of 2002 per Dave Brown's excellent "The
Winterizing Post" instructions. Treated fuel with Sta-Bil (approx 5
gallons of fuel in tank), started motor, let it run a while, fogged
the carbs, disconnected fuel line, fogged carbs some more as it
sputtered and died. Pulled plugs and fogged the cylinders. Turned
the motor over by hand to distribute the fogging oil.
Didn't try to start it again until April 2004. (We live on a large
lake and the water level is way down for dam repairs so we didn't use
the boat at all in 2003.)
Filled tank with fresh fuel on top of the old fuel.
Started boat in driveway (with ear muffs) without much problem.
Launched the boat. My wife puttered around for about two hours and
she said it ran OK. She never did open it up very much. I joined her
and started out at my cruising speed -- about 3000 RPM. RPM's soon
dropped and it stalled. Was not able to restart it. Had to get towed
in.
Local mechanic said he checked compression on all three cylinders
(normal), then spark (normal) and then examined fuel. Said it had
trash and water in the fuel and the carbs were "all stopped up." Paid
him $637 to rebuild carbs and drain the tank and get it running. He
said Sta-Bil is only good for about 6 months. (Their web site
http://www.goldeagle.com/ says 12 months or even 24 months if you
double the dosage.)
Launched it again. Had trouble starting it. It ran about 5 minutes
at low RPM's then died and could not get re-started. Had to tow it in
again.
Same mechanic now says top cylinder has no (or little - -can't
remember) compression. Says either rod is disconnected or possibly it
ate a reed valve. Says he's seen a fair amount of problems with this
vintage Merc 60. Says repairs will cost $2500 - $3500.
Together we theorized possibly the top cylinder was running lean
becasue it was gummed up and the lack of fuel/oil mis to that cylinder
may have damaged it.

1. Do you think the diagnosis is reasonable?
2. Do you think estimate of repair is reasonable?
3. Motor is on a 10 year old pontoon that needs other cosmetic work.
Even if it had no motor problems, the boat would probably be worth
around $4000. I can probably get $500 to $1500 for it in it's current
condidtion. Would you repair it or try to sell?
4. I am an experienced do-it-yourselfer. I build houses and know
carpentry, electrical, plumbing, HVAC, etc. Just never did much with
motors. Could I get a book and re-build it myself?

On Tuesday 13 July 2004 4:19 pm in rec.boats sunedog wrote:

Appreciate any help you can provide on the following:

1995 Tracker 21' Pontoon boat with 60 HP Mercury outboard (with oil
injection).
Summer of 2002 - Motor ran OK but periodically started to lose RPM's
while under way. I would be cruising at about 3000 RPM's and it would
suddenly drop down below 1000 RPM. If you played with the throttle,
it would resume normal speed and not show problem again for quite some
time (hours).

Sounds like a blocked fuel tank breather pipe or possibly
a clogged filter. Almost certainly fuel starvation of some kind.

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