I have a late 1980's model 60hp Johnson ob (on an 18' boat) with a problem
that I hope someone can help me make sense of.

It was running fine at the end of the season, but wasn't charging the
battery, so over the winter I took it to a shop that determined the
rectifier was bad. They replaced the rectifier, which corrected the charging
problem, but then the engine wouldn't open up under a load--well before the
boat could get on a plane, the motor would bog down and die. Using the
"neutral throttle" the motor would rev up like normal.

Back to the same shop, where they said the carbs needed to be rebuilt, which
they did. Back in the water, same story, engine bogs down under a load. But
then I noticed a ringing rattle under the cover, and found the flywheel nut
loose; I could remove it with my fingers.

Back to the shop, and now they say the shifter is not able to open the
throttle when in gear. They put on a new shifter, but it has made no
difference, it still bogs down.

I believe coincidences are rare. My suspicion is that when they worked on
the charging problem, they removed the flywheel (am I correct to assume this
would be done?) and never tightened it afterwards. Would a loose flywheel
cause the problem I've experienced? Could running with the flywheel loose
damage the fit where it can't be tightened properly, and the problem
continues? I suppose they could have screwed up the carbs when they put kits
in, but the performance of the engine didn't change any so I don't think
that's it.

Am I off base here? Any ideas?

Thanks for any suggestions.

I believe coincidences are rare. My suspicion is that when they worked on
the charging problem, they removed the flywheel (am I correct to assume this
would be done?) and never tightened it afterwards. Would a loose flywheel
cause the problem I've experienced? Could running with the flywheel loose
damage the fit where it can't be tightened properly, and the problem
continues?

If the flywheel was loose enough, there is a possibility that it wasn't seated
in the keyway. The flywheel could cause the engine to be out of time. If so it
would or could be retarded enough to not get full power.

Leanne

Garland Gray II wrote:

I have a late 1980's model 60hp Johnson ob (on an 18' boat) with a problem
that I hope someone can help me make sense of.

It was running fine at the end of the season, but wasn't charging the
battery, so over the winter I took it to a shop that determined the
rectifier was bad. They replaced the rectifier, which corrected the charging
problem, but then the engine wouldn't open up under a load--well before the
boat could get on a plane, the motor would bog down and die. Using the
"neutral throttle" the motor would rev up like normal.

Back to the same shop, where they said the carbs needed to be rebuilt, which
they did. Back in the water, same story, engine bogs down under a load. But
then I noticed a ringing rattle under the cover, and found the flywheel nut
loose; I could remove it with my fingers.

Back to the shop, and now they say the shifter is not able to open the
throttle when in gear. They put on a new shifter, but it has made no
difference, it still bogs down.

I believe coincidences are rare. My suspicion is that when they worked on
the charging problem, they removed the flywheel (am I correct to assume this
would be done?) and never tightened it afterwards. Would a loose flywheel
cause the problem I've experienced? Could running with the flywheel loose
damage the fit where it can't be tightened properly, and the problem
continues? I suppose they could have screwed up the carbs when they put kits
in, but the performance of the engine didn't change any so I don't think
that's it.

Am I off base here? Any ideas?

Thanks for any suggestions.


Coincidences can happen.... But I don't think that the charging problem
is related to the rough running.

More likely of coincidence is that your gas got bad over the winter,
which gummed up the carbs and fuel filter(s) along the way and caused
the rough running. Bogging down is either lack of fuel, bad timing
advance, or bad wires (in order of likelihood). The loose flywheel is
sometimes a sign of less than adequate maintenance, which could be
another coincidence, part of the cause or an effect of the real cause.
The flywheel nut is there only to keep the flywheel from flying off. If
it's on the shaft, the key's probably in the keyways and keeping the
timing close enough to right.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Thanks to all of you for your thoughts on this matter. I wanted to make sure
my suspicions were not unreasonable.
This weekend I'll take a close look at the flywheel, etc.

Problem could also be in the gearbox, if it revs up in neutral and not when in gear, the gearbox could be causing the headache!