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1973 evinrude no start

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Kirknannen

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I have a 1973 evinrude model 85393m. I am currently battling a no start condition. Engine has good spark, new plugs. The plugs were replaced due to them being old. Ive taken the carbs off and looked for debris and everything was clean, so reassembled and mounted back on. Still have a no start. Engine ran last year until i had a seal go bad in lower unit. Took lower unit apart and replaced the seal, but now will not start. Can get it to run for a few seconds at times on a quick burst of starting fluid. Looking through the cards, i found 2 of the idle screw plugs loose and tightened them down. Manual doesnt give a adjustment procedure for the plugs. Engine appears to have type 3 carbs based on build, but manual states it has type 2 carbs?
 
Well, i know all cylinders have some compression. Didnt bring my guage home from work to check. But after 10 key cycles the plugs still look bone dry like not getting any fuel? Even went and got new gas just to be sure. Guess my biggest question would be should the idle screw plugs be tight or are they supposed to be loosened to a certain point?
 
Drain the float bowls in a small dish and see if any water is in the bottom of the dish? Never use starting fluid on a two stroke it has no oil you can damage the engine. With the plugs off of the float bows pump the primer until you get good fuel mix coming out the nput the plugs back in and pime it good and see if she pops? It sounds like you just slugged some water into the carbs?
 
Kirknannen said:
Ive taken the carbs off and looked for debris and everything was clean, so reassembled and mounted back on.
Click to expand...

This right there sounds like a big waste of time to me..... Do you REALLY mean you took the carb apart, just LOOKED at it and put it back in WITHOUT any cleaning?.....
Because I can tell you after recent experiences of carb that I had to remove AND clean more than once before getting a good running motor, looking at a carb that "seems"clean to your eyes, means just about nothing.
The chances that you will see the spec of grime, rust, sand, whatever it is that may clog one the multiple tiny holes inside the carb, are close to zero.
So if I understood your post correctly, and you did NOT spray the carb in EVERY SINGLE accessible orifice, after removing all jets, needles and welch plugs, as well as pushing a strand of thin wire through the high speed jet, and blow air everywhere, then this is the first thing you have to do.
As I said before, I went through that routine once recently, the motor ran great for about 20 minutes and then stalled, and would only run again with the choke fully on.... I took the carb apart AGAIN, it looked clean as a whistle, but still went through the routine described above, and now the motor is running fine again, and for good it seems this time....
(Just forwarding tips I gathered here from experts such as Joereeves, racerone, kimcrwbr1 etc....and it worked for me!)
Good luck, the good news is you quickly become an expert at taking these things off and putting them back on, now I can do that in not time! lol
 
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Jupiter Dinghy said:
This right there sounds like a big waste of time to me..... Do you REALLY mean you took the carb apart, just LOOKED at it and put it back in WITHOUT any cleaning?.....
Because I can tell you after recent experiences of carb that I had to remove AND clean more than once before getting a good running motor, looking at a carb that "seems"clean to your eyes, means just about nothing.
The chances that you will see the spec of grime, rust, sand, whatever it is that may clog one the multiple tiny holes inside the carb, are close to zero.
So if I understood your post correctly, and you did NOT spray the carb in EVERY SINGLE accessible orifice, after removing all jets, needles and welch plugs, as well as pushing a strand of thin wire through the high speed jet, and blow air everywhere, then this is the first thing you have to do.
As I said before, I went through that routine once recently, the motor ran great for about 20 minutes and then stalled, and would only run again with the choke fully on.... I took the carb apart AGAIN, it looked clean as a whistle, but still went through the routine described above, and now the motor is running fine again, and for good it seems this time....
(Just forwarding tips I gathered here from experts such as Joereeves, racerone, kimcrwbr1 etc....and it worked for me!)
Good luck, the good news is you quickly become an expert at taking these things off and putting them back on, now I can do that in not time! lol
Click to expand...
Sorry guess i didnt clarify. Every part i took out got cleaned. Definitely didnt take me very long to pull them. Only parts i did NOT take out were the orrifices. And all cylinders have 135lbs of compression so thats not it. Noticed battery getting low, figured id recharge it and see if maybe i let the battery drain too much when checking components for everything to work correctly. Once charged im going to check the timing. Talked to the previous owner, guess he always used starting fluid to get it going initially. That statement kinda scares me, but goodcompression calmed the nerves slightly!
 
Ok, ive had a thought and figured i might as well add it here. The lower unit was removed by tipping the motor up (no power trim) and removing the lower unit. Any possible way that whatever fuel that was in the crankcase could leak past the reed vavles making the engine not start due to lack of fuel in crankcase? Just had this thought while rereading the manual seeing what i may have missed. Thinking about using a spray bottle and injecting fuel into the crankcase to see if it helps. Timing and compression are dead on but seeing no fuel in the piston tops. I know in the car world this seems like a classic lean condition, but i mainly work on fuel injected 4 stroke motors. Im a car mechanic by trade. I know ive put fuel down carbs in car motors to get the intake wet and fire em over in the past but only used a partial cup. Any thoughts?
 
The carbs turn the fuel into a vapor and pulls the vapor into the crankcase on the up stroke intake/compression as the piston is going down power/exhaust it is also charges the fuel vapor in the crankcase that charge pushes out the exhaust and fills the cylinder with fuel vapor. To answer your question no tilting the engine is more likely going to flood the crankcase with raw fuel causing a flooded condition. Try putting fuel mix directly into the cylinders and see if she pops? I use a length of vacuum tubing and stick it into the tank and plug one end with your finger stick the other end in the plug hole and release your finger. If she fires up momentarily then you have a fuel supply issue. There are three main causes, dirty carb, broken reeds or crankcase seals. Always start with the basics we need compression numbers and does the plug wires jump a open air gap of at least 3/8 inch with a brite blue snap with a spark gap tester?
 
All jets are fixed jets meaning that fuel is metered thru the ID of the jets. There is no adjustment. All jets must be snugged down tight.

You say that engine fires with starting fluid... don't use that stuff, use premix in a spray bottle. You continue on to say that (in not so many words) that it won't fire otherwise. That indicates that fuel is not flowing thru the carburetors!....... clogged high speed jets.

Clean the high speed jets carefully with a piece of single strand steel wire... solvent and air pressure just doesn't do that job properly.

I'm assuming that the choke works?
 
kimcrwbr1 said:
The carbs turn the fuel into a vapor and pulls the vapor into the crankcase on the up stroke intake/compression as the piston is going down power/exhaust it is also charges the fuel vapor in the crankcase that charge pushes out the exhaust and fills the cylinder with fuel vapor. To answer your question no tilting the engine is more likely going to flood the crankcase with raw fuel causing a flooded condition. Try putting fuel mix directly into the cylinders and see if she pops? I use a length of vacuum tubing and stick it into the tank and plug one end with your finger stick the other end in the plug hole and release your finger. If she fires up momentarily then you have a fuel supply issue. There are three main causes, dirty carb, broken reeds or crankcase seals. Always start with the basics we need compression numbers and does the plug wires jump a open air gap of at least 3/8 inch with a brite blue snap with a spark gap tester?
Click to expand...
Well, the spark is really good. Will jump well over 3/8 gap. Gonna double check my compression numbers and will post them shortly
 
joereeves said:
All jets are fixed jets meaning that fuel is metered thru the ID of the jets. There is no adjustment. All jets must be snugged down tight.

You say that engine fires with starting fluid... don't use that stuff, use premix in a spray bottle. You continue on to say that (in not so many words) that it won't fire otherwise. That indicates that fuel is not flowing thru the carburetors!....... clogged high speed jets.

Clean the high speed jets carefully with a piece of single strand steel wire... solvent and air pressure just doesn't do that job properly.

I'm assuming that the choke works?
Click to expand...

Choke works manually. Think thats why the guy had so many issues initially starting. Kept trying to use the warm up lever, but that lever had a broken cable. So i just been using the manual choke
 
Found 90 psi on cylinder 1 and 3. Approxemitly 80-85psi on cylinders 2 and 4. Seems slightly low doesnt it? I know its been a few months since this engine has ran, maybe numbers are lower just due to engine has been sitting?
 
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Well, just thought id post a update. Decided on spraying 50:1 fuel mix directly past the throttle blades then closing blades and trying to start. About 3rd crank. Motor sputtered. 5th try motor idles for a couple seconds. Now on 6th try found spark slightly off, just make slight adjustment and motor running. Thank you everyone for your help. Going to pull all orifices from carbs and clean them or replace based on wear that i find. Should be in great shape now. Thanks again everyone. Happy trails on the water.
 
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