90 Johnson 60hp off idle problem

eaglejax

Seaman Apprentice
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Dec 27, 2013
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37
This motor was brought to me after sitting for approx. 10 years and I was asked to get it going. I've had idle issues from day one and when I could keep it idling in gear then get it to WOT it would run a mile or two then start losing power and shut down. Would not crank up again till I got back home. Still having stalling problems and when I took it out last couldn't keep it running. What I've been thru so far I'll list;
Replaced the electricals. Stator: not charging, Timer Base: Bad res. readings, Coils: One had weak intermittent spark, Power pack, Rectifier, Carbs were taken off and cleaned, New head gasket
Replaced upper crankshaft seal, T-stat, Temp sensor, VRO removed and standard fuel pump installed. OMC fuel fittings at tank and motor replaced with barbed fittings. Low idle screws set 1/2 - 2 turns out and fuel spits from low idle jet but not concerned with that yet. I'm having to idle around 1300 rpms in neutral to keep it running in gear , in a barrel. still shutting down after around 30 seconds but the back pressure may be too much. It smokes a little heavy and I'm wondering about sticking rings. Compression readings on my not so good gauge are 90lbs. cyl.s 1, 2, &3. I tried pulling wires as it idles to see if I'm losing a cyl. Motor runs at idle with #1 and #3 connected then with #2 and #3 connected. Will not run on upper two cyl.s as pulling #3 it dies. Linc & Sinc was the first thing checked and I tried spraying starter spray along the crankcase split line to see if rpms would raise while running indicating a seal leak but no problem there. Any thoughts?
 

racerone

Supreme Mariner
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Dec 28, 2013
Messages
36,532
Invest or borrow a proper compression gauge and post the numbers..-----Baffling to me why all these parts had to be replaced.----Any visible scoring when head was off ??----Does the tell tale hose originate off the side of the block, or was it moved to the top ?
 

eaglejax

Seaman Apprentice
Joined
Dec 27, 2013
Messages
37
Invest or borrow a proper compression gauge and post the numbers..-----Baffling to me why all these parts had to be replaced.----Any visible scoring when head was off ??----Does the tell tale hose originate off the side of the block, or was it moved to the top ?
Yeah I've needed a good quality gauge for awhile. When I pulled the head I noticed no scoring but might pull it off and check again if I can't find anything else . The telltale hose comes off the side of the block. As far as the electricals, The new battery kept dying and wasn't charging. checked resistance which was not in spec. and I don't remember checking running output. New stator charging battery at 13.6v. Resistance checked the timer base because of weak spark on #3 cyl. One lead bad so I replaced it. One coil primary reading questionable so changed all three and the rectifier to finish it off and make sure no ignition problems. 34 yr old motor that's been sitting is bound to have problems. The motor belongs to a family member and I told him that if one or two parts are questionable I would rather replace all than have him bring it back I was watching it run early morning and noticed the fuel/air pulsing from the middle carb heavier than the other two and has me wondering if the reeds are getting too weak and maybe not holding crankcase pressure but it has no stumbling or misfiring on throttle.
 

racerone

Supreme Mariner
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Dec 28, 2013
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36,532
There was a service bulletin in 1994 to move the tell tale fitting to the top of the block.----Therefor motor has not been at a shop that cared I think.----Just my opinion.
 

eaglejax

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Joined
Dec 27, 2013
Messages
37
There was a service bulletin in 1994 to move the tell tale fitting to the top of the block.----Therefor motor has not been at a shop that cared I think.----Just my opinion.
Thanks, I will see if I can find that info. I don't see anywhere it might go other a threaded hole in the block behind the T-stat. Threaded but no plug inserted and looks like that might be it. I'm running as I'm posting. Running in drum and idle fluctuating 1060-1200. When putting in gear it will take throttle fine if I choke it and I hadn't tried that so far.
 

racerone

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Dec 28, 2013
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36,532
The latest water pump kit has the parts / instructions for the cooling system upgrade.----A wise man would act on this.
 

eaglejax

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Dec 27, 2013
Messages
37
The latest water pump kit has the parts / instructions for the cooling system upgrade.----A wise man would act on this.
I'll check that out. Already did the impeller but didn't do the complete kit.
Thanks
 

saltchuckmatt

Lieutenant Commander
Joined
Jul 19, 2019
Messages
1,932
Does your overheat alarm work? Does the paint look scorched? Sounds like an overheat situation.
 

cyclops222

Petty Officer 1st Class
Joined
Mar 21, 2024
Messages
319
A worn out set of intake REED VALVES will prevent a great, easy to adjust idle speed. So will stuff stuckin them.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
13,043
Reeds usually last many Thousands of Hours, rarely breaking/wearing out, however they are Prone to Damage from unnecessary Handling/Touching
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,653
That engine has a bridged exhaust port and if weak water pump or overheated, bridge will scuff exhaust side of piston. You will see lil scuffing on cylinder wall. One surefire sign is if it will idle and you slowly advance throttle , if it sounds gargled/bubbly thru carb throats its scuffed.
 

cyclops222

Petty Officer 1st Class
Joined
Mar 21, 2024
Messages
319
You never said you checked if the sparkplugs are correct ones Or that you replaced them.
 

eaglejax

Seaman Apprentice
Joined
Dec 27, 2013
Messages
37
Thanks for all the replies. You guys have always been a lot of help when i think I've covered everything but still scratching my head. Latest update : Spark plugs are correct, overheat alarm not working yet but that's next so after running awhile I'm feeling the water stream. Water pump good and pressure is good. Haven't done the water line upgrade yet as I want to find out the exact location to drill and tap the fitting on top of the case. I saw on you tube one person said drill about 1 3/8" from exhaust cover toward center of case but he used the brass fitting as a tap and only got three threads to hold the fitting. Haven't found the bulletin yet for info. and it looks like I need a 1/4"NPT to 1/8" barbed fitting. Previous owner had throttle stop screw almost maxed and the valves weren't opening which I missed. Runs fine WOT now and takes off better but still a little issue with idling in gear and intermittent stalling or hesitating giving throttle. When it starts to bog bumping the primer gets it going.
 

eaglejax

Seaman Apprentice
Joined
Dec 27, 2013
Messages
37
Less than $20.00 fix
 

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