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1980s Evinrude 15hp 2 stroke Start issues

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Grandmalips

New member
Got an old engine from a friend had not been run in years. However with starter fluid it would start on the first pull and run great at all speeds but starter fluid was required each time to start and it idled out twice near the end of the day (but again with starter fluid it would start again just fine). To fix this I figured a carb clean would be the way to go. However after cleaning and reassembling It will not start. It seems to turn over (occasionally running for a brief few seconds) like it wants to start but it will die before I can get it into gear or after applying throttle. I am suspecting the idle adjustment switch but I keep turning it and can not tell if I am closing it or opening it as i keep turning and turning it but it does not stop.

1. New Spark plugs were installed
2. New gas used before running it (added sea foam)
3. Soaked carb in carb cleaner and removed all not metal parts before doing so

Questions I need answered

1. Any insight on why this may not be starting
2. How do I properly adjust/reset the idle set screw because I cant seem to find out how to fully seat it no matter how much I turn it
3. What order should i troubleshoot

Thank you

Edit: Its a year 1990 2 stroke 15HP Model
 
Last edited:
flyingscott said:
If you are turning the screw in the plastic cover and it wont go tight the cover may be stripped. Expensive part.
Click to expand...

yep, getting that screw adjusted to factory as a starting point is key. I think it's 1.5 turns out. That dumb plastic dial won't help you if the needle is stuck. You will have to very, very gently use a pair of pliers to see if you can get it to rotate.
 
Grandmalips said:
...with starter fluid it would start on the first pull

1. New Spark plugs were installed
2. New gas used before running it (added sea foam)
3. Soaked carb in carb cleaner and removed all not metal parts before doing so

Questions I need answered

1. Any insight on why this may not be starting
2. How do I properly adjust/reset the idle set screw because I cant seem to find out how to fully seat it no matter how much I turn it
3. What order should i troubleshoot

Thank you

Edit: Its a year 1990 2 stroke 15HP Model
Click to expand...

#1 Never use starting fluid on a 2 stroke. That equates to ZERO lubrication for the engine as it runs. Always use a little pre-mix fuel and squirt that in the carb as you're troubleshooting

#2 Be sure to clean all passages and orifices in the carburetor with a small wire. Just soaking may not be enough to dislodge a piece of cludge that's stuck.

#3 Idle screw: turn in until lightly seated then back off 1.5 turns. That's a good place to start.

#4 Troubleshooting order:
Compression (even and over 100PSI on both)
Spark - should jump 7/16" with an air gap tester
Fuel - Check all fuel flow to the carb. Make sure pump diaphragm is good and no blockages. Make sure everything in the carb is clear

If you have all 3 of these in good shape it should start. Also remember from a cold motor to use the choke when trying to start.

KJ
 
Evinrude Engine Tune-Up Service manual. In addition, the Seloc book says 100 psi "but even compression between cylinders is much more important than absolute values". If you check on Youtube, you'll see several running around 80 or 90 just fine.
The fact that starter fluid helps may indicate that it's running rich or lean or spark isn't good. You could test the spark with a tester...
 
Last edited:
boatbear said:
Evinrude Engine Tune-Up Service manual. In addition, the Seloc book says 100 psi "but even compression between cylinders is much more important than absolute values". If you check on Youtube, you'll see several running around 80 or 90 just fine.
The fact that starter fluid helps may indicate that it's running rich or lean or spark isn't good. You could test the spark with a tester...
Click to expand...
I am curious put a pic of that up. I have never seen an OMC manual that had an actual spec in it. All mine says for those motors is it must be within 10-15%
 
bigtime_mcalpine said:
yep, getting that screw adjusted to factory as a starting point is key. I think it's 1.5 turns out. That dumb plastic dial won't help you if the needle is stuck. You will have to very, very gently use a pair of pliers to see if you can get it to rotate.
Click to expand...


Thanks for all the help and replys

The screw turns but is it changing the fuel/air ratio ??? that I cant really tell. I actually have 2 of the same motor (one extra is for spare parts if needed) so its not a big deal if i need to replace somthing
 
I feel like this is good advise but I am not sure how to check compression. I will look it up thanks. Also i didnt use a wire just compressed air from my compressor to spray out the passages. From what I can tell everything is good as far as compression, spark, and fuel flow. I still think my issue is the low idle adjustment, which I cant seem to get right. I verified the diaphram and carb were good and correct so its not that.
 
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