83 johnson 35hp

[Ed Moore]

Greetings,
I purchased and rebuilt an old 20ft pontoon boat.
The engine is the original 35hp johnson two cylinder two stroke.

It had been sitting unused for at least 12 years.
I has very little use/low hours.

I have replace the fuel tank, fuel lines and connectors. Checked/cleaned the
fuel pump, installed new sparkplugs, removed and cleaned the carburetor.

The engine started and seemed to run properly on the water hose/ears.
I have used the boat a few times this summer. The first use was for a very limited trail to just check everything out.

It has since developed a stall when above 1/2 throttle. Pumping the bulb has no effect. I will continue to run but won't take full throttle. I have noticed that it will run much better with the choke pulled about half way out.

Seems like a lean condition. The carburetor was really badly clogged with 12 year old fuel (the float bowl had what looked like tar in the main jet area).

I was planning to remove the carburetor again, ordering fuel pump and carburetor rebuild kits. When taking the boat to the ramp after the last trial the overheat alarm sounded just at the ramp.

This was not unexpected. The previous owner had a spare pump impeller with the boat. I don't think it has overheated to the point of damage.

Yesterday I removed the lower unit, replaced the impeller, and checked the pump housing. I found very little wear so only replaced the impeller.

There was no real damage/wear at the waterpump so I'm not sure why it overheated. After installing the lower unit with the new impeller, starting it with the hose/ears I still have no evidence of water reaching the powerhead (no water from the "pee hose") I din't let it run long enough to caused the alarm to sound.

I am not 100% percent sure of two things. Did the water pipe find its way to the correct opening at the bottom of the engine. Is the thermostat opening.

My Questions,
Should I continue repairs on this engine. I like the size and power of this engine. It seems simple enough with one carburetor. The basic engine seems sound (good compression. shifting and gears seem fine, starts easily).

I am concerned that the extended non-use may cause other issues as this boat is used.

Are there any johnson/evinrude outboards that might be a better choice.

Should I go to a modern 4 stroke?

I have been a automotive technician for years but have limited marine knowledge. I don't mind the work but don't want to continue if this engine will continue to fail.

Sorry about the long post!

Any thoughts..

Thanks,
Ed Moore

[boats.net]

Those engines are not bad, worth fixing if it is in good condition.

[Ed Moore]

Can anyone tell me how to make sure the water pipe is in the correct location after reinstalling the lower unit? Recent impeller replacement.
Still no water is coming out of the indicator hose (pee-hole).

83 Johnson 35hp.
Thanks for any help.

[Grousehunter12]

Can anyone tell me how to make sure the water pipe is in the correct location after reinstalling the lower unit? Recent impeller replacement.
Still no water is coming out of the indicator hose (pee-hole).

83 Johnson 35hp.
Thanks for any help.

I just replaced a water pump on a 2005 25hp. that would not pee before or after replacement , I noticed crude in the pee hole , dug out crude with ice pick , still no pee , removed indicator hose from the housing and flexed it around , still no pee , removed indicator hose from engine block and blew out with air , placed hose back on block and fired engine . Pisses like a race horse ! I too thought it strange that I could find no damage to the original pump . Give it a try before tearing back down to check the water feed tube .

[boats.net]

I agree with Grousehunter12, blow out the cooling system with compressed air. If still no luck, remove the lower unit again, this time install the water tube in the block first then install the lower unit. It is easier to line up the tube into the lower unit than the block.

[Grousehunter12]

I agree with Grousehunter12, blow out the cooling system with compressed air. If still no luck, remove the lower unit again, this time install the water tube in the block first then install the lower unit. It is easier to line up the tube into the lower unit than the block.

I had my water feed tube out on work bench , installed tube into block with a good stiff grease helping hold it in place, then used the old pump housing slipped down onto the shaft to line the tube back into the correct position , you have a couple of inches to see and move the old housing around while holding the lower unit in place , removed lower unit and old pump housing , greased the tube hole on the new housing and reinstalled the lower unit , wiggled a time or three and everything slid into place .

P.S. Those low horsepower engines will last 50 years or more if taken care of . Most important thing is never let it get HOT ! I would also run a good gas treatment (STA-BIL) in every tank of that crap called gasoline today. I also like to pull the gas line and let the engine run the gas out of the engine while on the trailer . I even go so far as emptying the gas line back into the tank .The high horsepower motors are going to blow , the only question is when !

[Ed Moore]

Thanks for the response.

I removed the gear case and fitted the water tube to the crankcase first.
Now I am sure the water is reaching the engine. I have water from the tell-tale hose.

It ran on the "muffs" for 10 min. and never seems to overheat.
The flow seems very weak but it is steady. I need to put it in the water to be sure the cooling system is working.

Do you think i should pull the cover to check the thermostat and water passages in the crankcase?

Next is carb. and fuel pump kits.
I am concerned about the seals at the shaft to gear case and the prop shaft seal. There was no water in the gear case after limited use last fall.

Any suggestions. I want to get this motor in good condition.

Thanks.
Ed Moore