89 Johnson 140 overheat issue.

misery

Petty Officer 3rd Class
Joined
Jul 18, 2010
Messages
98
I recently picked up an 89 Johnson 140 hp. The motor hasn't been run for five years, but after some tinkering I got it running but it tripped the overheat alarm after about two minutes of running in a barrel. I noticed that it wasn't putting any water out of the tell tale, so I put a flusherette on it and it started to put water out of the tell tale, but it still overheated.
Is this a sign that my impeller is toast or is there another reason for this condition?
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,022
Re: 89 Johnson 140 overheat issue.

Drop the lower unit!!!! It is new to you and it needs to be checked. The entire process is under an hour to drop, inspect, (replace impeller if needed - I would)and re-install. The 89 is a great model year. If you don't do the right thing then your wallet could be toast.
 

V153

Lieutenant Commander
Joined
Apr 16, 2011
Messages
1,764
Re: 89 Johnson 140 overheat issue.

Yes. Replace the impeller. There's a possibility the tstats could be effed up too, of course, considering how long it sat. But I would highly recommend putting at least a new impeller in it for starters
 

misery

Petty Officer 3rd Class
Joined
Jul 18, 2010
Messages
98
Re: 89 Johnson 140 overheat issue.

Ok so I replaced the impeller on the motor and now i have a couple of new issues that i've noticed. The first issue that i've noticed is that it takes quite a few seconds for water to begin coming out the tell tale. Is this because of the amount hoses and such that the water has to pass through? The feed for the tell tale is on the top of the port head, so i assume that the block and heads have to fill before it can exit out the tell tale. The other issue I noticed is the strength of the of the tell tale stream. Its not that strong, on a garden hose. The tell tale hose seems rather large on this motor, about 5/16" id. Should this be stronger in the water?
Thanks for all the help.
 

schematic

Lieutenant Junior Grade
Joined
Jan 12, 2008
Messages
1,102
Re: 89 Johnson 140 overheat issue.

the telltale has a vent incorporated in it. The stream is not very strong
 
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