1989 70 - won't idle in gear

OK, I have a 1989 Johnson 70 that will not idle in gear for longer than about 30 seconds. It will idle forever in neutral. I have already changed the idle mixture as detailed here: http://forums.iboats.com/showthread.php?t=361234. The mixture change improved things, but it still won't idle for long. I have also done a full rebuild and link'n'sync is right on per the manual, with the exception that the idle speed is a little high.

To reiterate my question from the other thread, is it possible that having the idle speed set too HIGH is causing the stalling? I set the motor to about 1200 on the muffs, which worked out to around 850 RPM on the water, against the spec of 700.

I would have thought that having too low an idle speed would make it stall, but maybe too high is worse? Unfortunately it's not really easy to experiment - I need a quiet lake and there aren't any around here.

Thanks for any assistance.

Tim

Re: 1989 70 - won't idle in gear

1200 on the muffs, 850 in the water? Is that 850 in gear, or in neutral?

just a hunch...those two exhaust relief ports on the aft end of the motor just below the powerhead -- are those by any chance submerged at idle?

Answer your question: my opinion, 850 idle speed shouldn't kill it like that. sounds to me like it's a little rich at idle, gradually flooding out.

Is the primer bulb still firm when it quits? Restarts easily? Ever have trouble powering on to the trailer?

p.s. where is "around here?" surely you can get some quiet time early on a weekday. Call in sick maybe?

Re: 1989 70 - won't idle in gear

850 is in gear, in the water, moving. The relief ports are well above the water.

Primer bulb stays firm, restarts easily. I don't power load so can't tell you about that.

You may be right about the mixture - I've tried going richer, maybe it's time to try the other way.

I like your thinking about a sick day...

Tim