I need your help on a 84 johnson 90

bamadave

Petty Officer 1st Class
Joined
Mar 24, 2005
Messages
391
hi guys, I have a 84 johnson 90 v-4 that is not peeing and no top end at wot. the boat has sat up for 3 years. before I tried to start it, I dissasembled both carbs and cleaned them. not alot of crud in them but the jets on the left side of both carbs were stopped up. I cleaned and reassembled them and the engine started almost immediately under the muff. there was no water coming out the pee hole but thought maybe it had not come up to temp. I put the boat in at my launch and ran it out maybe 100 yards but would not rev up and plane. still no water coming out the tell tale so I brought it back instantly. I removed the engine cover and touched the heads but they weren't so hot you couldn't touch them. I ran a small piece of wire in the water outlet but didn't feel any obstruction. I was told by the best boat mechanic on the lake that this engine had a nearly indestructable impeller and it should be fine. So, for the questions, what should I be looking for as to (1) no top end, (2) no water at the tell tale? could the thermostat be frozen shut and if so, how hard is it to replace? I will pull a compresion check and report back. Thanks for everyone who has input to this forum as I have used it before and I know a lot of you offer your time and wisdom without much reward. I'm here to say a big THANK YOU!
 

bamadave

Petty Officer 1st Class
Joined
Mar 24, 2005
Messages
391
Re: I need your help on a 84 johnson 90

I just checked the S#.it's a 85 instead of a 84.<br />Sorry
 

dcappotto

Cadet
Joined
Feb 26, 2004
Messages
8
Re: I need your help on a 84 johnson 90

Since the motor was sitting sitting around for 3 years I would definitely start with a new water pump. I would install a complete kit not just the impella.
 

Walker

Captain
Joined
Jun 15, 2002
Messages
3,085
Re: I need your help on a 84 johnson 90

And don't ever take your boat to that "best boat mechanic on the lake." Your impellor is made of mostly rubber. Ever seen a car tire that has been sitting for 3 years. Lots of cracks yes??
 

bamadave

Petty Officer 1st Class
Joined
Mar 24, 2005
Messages
391
Re: I need your help on a 84 johnson 90

I checked the compression and all 4 cylinders are 135.
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: I need your help on a 84 johnson 90

Replace both the water pump and the thermostats.
 

bamadave

Petty Officer 1st Class
Joined
Mar 24, 2005
Messages
391
Re: I need your help on a 84 johnson 90

Hey guys, thanks for the input. Replaced the water pump and went back thru the carbs. I blew out every orifice in both carbs and reassembled. When I put the boat back in the water, it ran like a screaming banshee. This forum is the greatest but only because of the people who take time to help those like me. I'll buy each of you a drink or wait. I'll have a drink for each of you instead,THANKS AGAIN
 
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