1973 evinrude 65hp triumph outboard wont run in water but will on muffs.

Hotrod23

Recruit
Joined
Jul 2, 2020
Messages
1
Good Afternoon all,
I am new to Iboats and I am very happy to have found this community. I just got a FREE boat and motor and it actually is awesome. The motor sounds strong when I tun it on dry land but a soon as I put it in the water it wont run. I am pretty sure I has everything to do back pressure. Basic check points completed:
spark
- I have double and triple checked the spark and even tried drop cyclender testing. Some slight changes but will do just fine.
fuel
- I just replaced the fuel pump and made sure all the basic fueling things are tight functioning.
- I have not yet cleaned the carbs but I did peak in them when I got the boat. I did not see anything major.
Air -Help
- this is where I could be confused . I think it might be back pressure in the exhaust if this the case how do I remedy it?

Also it seems this is not a strange thing at all... Has anyone experienced this and what was the solution. Also what is the likely hood that this is something simple.

more or less where do I start?



P.s. HHHHHHHEEEEEEELLLLLPPPPPP!!!!!!!!
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
Classic symptoms of a worn out motor.----Start with a simple compression test.---Costs no money to test that.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
That motor was notorious for water ingestion from leaking exhaust cover gaskets. Resulting in total powerhead destruction.
 

tkdrumr

Cadet
Joined
Feb 9, 2016
Messages
29
My "free" 72 Evinrude 65hp Triumph had the same symptom on the first sea trial a few weeks ago. It ran great on muffs but wouldn't go above 3K rpms on the water. I shut it down pretty quick and brought it back to the dock with the 9.9 kicker.

I had other clues:
- Wouldn't turn over on muffs after we got home. I used a socket on the flywheel nut with a breaker bar to get it past that point. I could hear it binding up.
- Took out the plugs ... 1 & 2 had some tan color to them but 3 was clean and dripping a little with water. This was the big indication. And, 3 was where the noise was loudest.

Before shelling out $ for the gaskets I poured in some mystery oil and let it sit for a while. Then I turned it without muffs or plugs to blow out the water/oil and then checked compression. Still about 126 in all three cylinders. But still I pulled the powerhead and exhaust covers to look at the pistons before going ahead.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
My "free" 72 Evinrude 65hp Triumph had the same symptom on the first sea trial a few weeks ago. It ran great on muffs but wouldn't go above 3K rpms on the water. I shut it down pretty quick and brought it back to the dock with the 9.9 kicker.

I had other clues:
- Wouldn't turn over on muffs after we got home. I used a socket on the flywheel nut with a breaker bar to get it past that point. I could hear it binding up.
- Took out the plugs ... 1 & 2 had some tan color to them but 3 was clean and dripping a little with water. This was the big indication. And, 3 was where the noise was loudest.

Before shelling out $ for the gaskets I poured in some mystery oil and let it sit for a while. Then I turned it without muffs or plugs to blow out the water/oil and then checked compression. Still about 126 in all three cylinders. But still I pulled the powerhead and exhaust covers to look at the pistons before going ahead.

AND???? Inner exhaust cover plate was warped, right?
 

tkdrumr

Cadet
Joined
Feb 9, 2016
Messages
29
I had some further thought on this. There was no telltale on this motor. I found an advisory on later motors to move the telltale from the exhaust manifold to the top of the head because of the potential to trap air. If that's the case, then having no telltale would be much worse. The heating/cooling cycle may have loosened some bolts and allowed the gasket to fail without actually warping the cover. I had two rusted bolts on the exhaust covers - upper left and lower right.

I had installed a telltale at the top of the head before that first sea trial. Water came out when the lower unit was in a barrel but not on muffs. That was before I replaced the gaskets. Now I've got water coming out the telltale even on muffs. I suspect it was sucking air through the failed gasket.

I've had it on the water a few times now. #3 plug now has some color and no water on it ... it takes off from idle with no hesitation and the motor gets up to 35mph @ 5300 rpms with no hesitation at all on my '74 Starcraft SS 16 tinny.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
Moving the tell tale and the service bulletin to do that did NOT APPLY to the 1972 model 3 cylinder motors.----
 

tkdrumr

Cadet
Joined
Feb 9, 2016
Messages
29
Moving the tell tale and the service bulletin to do that did NOT APPLY to the 1972 model 3 cylinder motors.----

Yeah, I got that. You did happen to note that I said "In later motors"? The engineers decided it was important enough to add a telltale to pretty much every 2 stroke water cooled outboard at some point after 1972, and then later to move it because it still wasn't as effective as it should be.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
Good luck with your motors.----The general public wants to see a motor peeing.----But most still do not know exactly what the tell tale is telling them.----Have a 3 cylinder 1988 60 hp in my truck.----Has a tell tale but motor is overheated / fried and needs rebuilding.----Oh----I have it sold , over the phone to a party 2 hrs away !!
 

tkdrumr

Cadet
Joined
Feb 9, 2016
Messages
29
You really haven't offered up much of a reason why it was wrong to add the telltale and conveniently ignored my assessment of the overheat issue and my reason for adding one. Don't worry about me, I had read MUCH information about this beforehand. Luckily this forum is filled with helpful advice. In fact, the post for the telltale came from iboats.

A little background .... I obtained one 72 triumph for free. Before getting too far into it I stumbled across what I thought was a decent deal on a 2001 Johnson 70. I didn't do my due diligence mainly because the seller was a member of the Coast Guard Auxiliary as well as a pilot. So I figured he would know more than most people the danger of sending someone and their kids on the water with a bad motor. That was a huge mistake. Long story short, I ended up tearing into the motor and found it had overheated (discolored crank) likely from oil starvation and had a badly worn crank journal which probably caused the piston slap that put a crack in it. That motor sits in pieces in my garage. I picked up another free 72 Triumph and between the two have a well running motor.

I sure hope you were upfront with that buyer about the issues, otherwise you are just as unethical as the seller of my POS, and bragging about it here as well.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,044
^^^^---All total nonsense.----Folks have driven away with my motors saying " no need to hear it run "----We know what you build and put together.----Not bragging at all , just stating the exact facts.
 
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