MagDarter

OUTBOARD EXPERTS

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okay... I’m stumped and need some help... 

 

been fiddling with my motor through the spring till now and everything seems to be working fine EXCEPT... It takes me 10-15 pulls (messing with my choke and throttle) to get my motor started... once the engine is warm... it starts on the first pull every time... spark plugs are new, new starter cord, carbs cleaned, throttle assembly adjusted... 

 

what do you think is causing the issue?  

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It's usually a lot easier to diagnose issues if you post what you actually have. Since it looks like you have a 1996 15hp OMC my guess would be that it could be as simple as the angle of the motor on the transom. Make sure the motor is tucked all the way into the transom as otherwise the fuel has a harder time flowing into the carb. Without the motor running it is gravity that causes the fuel to move from the carb throat into the intake. Once the motor is running the fuel will be pulled in so angle doesn't matter.

 

And you say "messing with the choke and throttle". Move throttle to "start". Pull choke on. If motor doesn't start on 3 pulls then push choke back in and try. That's what OMC recommends, not sure if that's what you are doing.

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1 hour ago, MdCrappie said:

It's usually a lot easier to diagnose issues if you post what you actually have. Since it looks like you have a 1996 15hp OMC my guess would be that it could be as simple as the angle of the motor on the transom. Make sure the motor is tucked all the way into the transom as otherwise the fuel has a harder time flowing into the carb. Without the motor running it is gravity that causes the fuel to move from the carb throat into the intake. Once the motor is running the fuel will be pulled in so angle doesn't matter.

 

And you say "messing with the choke and throttle". Move throttle to "start". Pull choke on. If motor doesn't start on 3 pulls then push choke back in and try. That's what OMC recommends, not sure if that's what you are doing.

Thanks for the reply.  It’s a 1996 Johnson 15hp 4 Stroke.  Motor is down and set on the transom with the cavitation plate even with the bottom of the hull.  Starting procedure is I prime the bulb until it’s hard and then take 3 cranks if nothing I put choke on and repeat that process until I’m able to get it to turn.  Normally it kicks with the choke on then I shut the choke and it usually starts not long after that.  Just don’t understand why so many pulls to get it going and having to give it a little throttle to catch.  

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Do you have a vacuum leak or a plugged passage in your carb?  Try squirting some carb cleaner into the carb then pull on the rope.  If it starts on first pull and runs for a few seconds then dies you might need to clean your carb.

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1 hour ago, whaler1889 said:

Do you have a vacuum leak or a plugged passage in your carb?  Try squirting some carb cleaner into the carb then pull on the rope.  If it starts on first pull and runs for a few seconds then dies you might need to clean your carb.

I’m not sure if it has something to do with the carb because usually when I get it running it stays running.  Just this week alone I was able to get the motor started Sunday in 8 pulls and then 1 pull after that every time she started and then yesterday I tried to do the same 20 pulls and nada couldn’t get it on gave up and will try again today or tomorrow.  It’s just so sporadic and I can’t figure out why 

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My father's lawnmower was acting the same way, I took the carb apart and cleaned it which solved the problem.  There was some sediment in the bottom of the bowl.  You may not be drawing enough gas into the engine for a cold start, but he other fuel circuits within carb could be ok, thus try a squirt of the carb cleaner then try to start.  Just might eliminate one possibility.

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2 hours ago, whaler1889 said:

My father's lawnmower was acting the same way, I took the carb apart and cleaned it which solved the problem.  There was some sediment in the bottom of the bowl.  You may not be drawing enough gas into the engine for a cold start, but he other fuel circuits within carb could be ok, thus try a squirt of the carb cleaner then try to start.  Just might eliminate one possibility.

Thanks!  I played around a little more with it today and eventually got it to start full throttle.  After that I was able to get it to start on 1 pull.  I also pulled the choke on when the motor was as running and that killed the motor.  I shut the choke off and then it wouldn’t start unless I went to full throttle.  

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Maybe need to adjust your carb. Also, not sure how they were cleaned but most deserve a rebuild and a clean is the halfway point to realize that is needed. 

 

Another thought is could be an issue with your fuel pump? Those diaphragms do go bad. Once there is draw, it may be working fine but not enough to start it w/o choking it?

 

Good luck. 

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On 7/1/2020 at 9:52 PM, MagDarter said:

Thanks!  I played around a little more with it today and eventually got it to start full throttle.  After that I was able to get it to start on 1 pull.  I also pulled the choke on when the motor was as running and that killed the motor.  I shut the choke off and then it wouldn’t start unless I went to full throttle.  

theres nothing wrong with it, you are causing the problem.

they will rarely start cold and dry, you have to nearly flood the engine with choke.

3 pulls to wet the cylinder and it should fire up. 

If not , repeat with choke.

 

If it runs ok once running the carb is good.

Consistent hard starts point more to link/sync needing attention.

Spark advance and carb need to be properly calibrated.

Timing should be fully retarded to help it fire when cold.

Thats why there is a start position on the throttle.

 

Check the cam roller has no flat spots.

https://www.leeroysramblings.com/Johnson_9.9_carb-fuel_pump.htm

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7 hours ago, jonesg said:

theres nothing wrong with it, you are causing the problem.

they will rarely start cold and dry, you have to nearly flood the engine with choke.

3 pulls to wet the cylinder and it should fire up. 

If not , repeat with choke.

 

If it runs ok once running the carb is good.

Consistent hard starts point more to link/sync needing attention.

Spark advance and carb need to be properly calibrated.

Timing should be fully retarded to help it fire when cold.

Thats why there is a start position on the throttle.

 

Check the cam roller has no flat spots.

https://www.leeroysramblings.com/Johnson_9.9_carb-fuel_pump.htm

Thanks! 

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Posted (edited) · Report post

Did you disassemble the carbs to clean them?  If you just spray carb cleaner into them you are not cleaning the jets, which is where a lot of carb trouble begins. As mentioned above pull them out, soak them in a good cleaner or better yet an ultrasonic tank, and rebuild them.

 

Also make sure the plugs are gapped correctly and and check for weak spark.

 

sam

Edited by sams

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16 hours ago, jonesg said:

theres nothing wrong with it, you are causing the problem.

they will rarely start cold and dry, you have to nearly flood the engine with choke.

3 pulls to wet the cylinder and it should fire up. 

If not , repeat with choke.

 

If it runs ok once running the carb is good.

Consistent hard starts point more to link/sync needing attention.

Spark advance and carb need to be properly calibrated.

Timing should be fully retarded to help it fire when cold.

Thats why there is a start position on the throttle.

 

Check the cam roller has no flat spots.

https://www.leeroysramblings.com/Johnson_9.9_carb-fuel_pump.htm

I tend to think joesg is more on to it than you understand and he really just reminded me of something

My family has more than a few 6-15 HP motors up on lake Champlain across 3 camps (cabins)

Each of them have their idiosynchrasies and like a starting procedure unique to themselves

you have to figure it out

 

As a general rule, it seems two to 3 pulls with full choke, then half choke is kind of a baseline, but like I said, each engine is an individual and likes it a bit different

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7 hours ago, sams said:

Did you disassemble the carbs to clean them?  If you just spray carb cleaner into them you are not cleaning the jets, which is where a lot of carb trouble begins. As mentioned above pull them out, soak them in a good cleaner or better yet an ultrasonic tank, and rebuild them.

 

Also make sure the plugs are gapped correctly and and check for weak spark.

 

sam

thats not cleaning the carb either, you should run wire through the jets to dislodge foreign matter that doesn't dissolve. But from the description the carb is not blocked.

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