Problem pull starting a 2 stroke mercury 35hp '89

[Brad1085]

Hi, I recently had a Mercury outboard 35hp '89 handed down to me. It was sitting for about 10 years so i decided to check things out (spark plugs etc). Everything looks fine i pulled the spark plugs out to check to see if i had "spark", and i do. I was pull-starting the motor during my checks, when I was happy i placed the plugs back in and went to start the motor, again by pull-starting. It would feel like a piston would top out then I couldn't pull anymore unless i released some tension and it would let me take a little more out but not much. When I took the plugs out again and tried to pull start (keeping plugs out) it was a nice smooth pull.

 

[Chris1956]

Re: Problem pull starting a 2 stroke mercury 35hp '89

You might check the type of spark plug required from that motor. A lot or them were gapless and 3/8" reach. If you have a gap-type plug or a 1/2 " reach plug, the piston could hit. Normally the piston has some clearance below the cylinder head, but I have no idea what spark plugs you are running. I normally ran NGK plugs in my motorcycle and the reach was 3/4" These would likely hit the piston, in your OB.

 

[Brad1085]

Re: Problem pull starting a 2 stroke mercury 35hp '89

it is a gapless 3/8 inch. I thought it may be to long, so i started backing out the plug to where it was almost out and it still had the same problem

 

[Mi duckdown]

Re: Problem pull starting a 2 stroke mercury 35hp '89

Brad. DON'T BACK OUT THE PLUGS and try to start unless you want to ruin.the threads SERIAL NUMBER OF MOTOR.

 

[Lone Duck]

Re: Problem pull starting a 2 stroke mercury 35hp '89

Hi, I recently had a Mercury outboard 35hp '89 handed down to me. It was sitting for about 10 years so i decided to check things out (spark plugs etc). Everything looks fine i pulled the spark plugs out to check to see if i had "spark", and i do. I was pull-starting the motor during my checks, when I was happy i placed the plugs back in and went to start the motor, again by pull-starting. It would feel like a piston would top out then I couldn't pull anymore unless i released some tension and it would let me take a little more out but not much. When I took the plugs out again and tried to pull start (keeping plugs out) it was a nice smooth pull.

I suspect your rewind is binding under load when trying to pull through the compression stroke. To check this ,remove rewind and use another rope on the emergency pully on top of the flywheel. Give it a pull with plugs in. If it pulls smooth repair rewind,If it does not and you have verified the plugs are correct, it is time to remove the head and check for other problems.

 

[racerone]

Re: Problem pull starting a 2 stroke mercury 35hp '89

You need to be able to give it a hefty pull to turn those over against compression.------------Electric start kits are available,-----Note --there is no cylinder head that can be removed for inspection.

 

[Brad1085]

Re: Problem pull starting a 2 stroke mercury 35hp '89

I suspect your rewind is binding under load when trying to pull through the compression stroke. To check this ,remove rewind and use another rope on the emergency pully on top of the flywheel. Give it a pull with plugs in. If it pulls smooth repair rewind,If it does not and you have verified the plugs are correct, it is time to remove the head and check for other problems.

Looking at the flywheel, it doesn't have any place to wedge in the rope to start wrapping the rope around.

 

[Lone Duck]

Re: Problem pull starting a 2 stroke mercury 35hp '89

Looking at the flywheel, it doesn't have any place to wedge in the rope to start wrapping the rope around.

Damn! looks like I am batting zero. Never had a motor without a emergency start pulley. Never had a motor that new. Whats the world coming too? In any case check your rewind.

 

[Brad1085]

Re: Problem pull starting a 2 stroke mercury 35hp '89

lol ok will do. I'm fixing the wiring to the starter now, just taking a bit of time not knowing how the wires are arranged. I can't seem to find any blueprints on the internet for this motor.

 

[Lone Duck]

Re: Problem pull starting a 2 stroke mercury 35hp '89

lol ok will do. I'm fixing the wiring to the starter now, just taking a bit of time not knowing how the wires are arranged. I can't seem to find any blueprints on the internet for this motor.

AAHHA!! That explains it. The rewind IS the emergency start. Before you spend to much time on rewiring, take jumper cables direct from batt to starter. neg to ground and pos to pos on starter. If it turns over smooth and quiet no rubbing ,clacking,or grinding sounds. Then you are good to continue getting engine to run.

 

[oldman570]

Re: Problem pull starting a 2 stroke mercury 35hp '89

Here is a link to a manual with wiring diagram that should work for wiring up the starter.
Boatinfo - Mercury Service Manual for 20jet-20-25hp
It is on page 75 or close to it, and is almost the same for most all smaller motors. Searching farther in the manual should get you a full diagram that will have all the wiring of the motor including the charge coil and rectifier charging system. JMO
Oldman570

 

[Lone Duck]

Re: Problem pull starting a 2 stroke mercury 35hp '89

Where did he go? What happened? Hope he fixed it, be nice if he told us though!

 

[Brad1085]

Re: Problem pull starting a 2 stroke mercury 35hp '89

I hooked the battery up to the starter, but the starter didn't work . This freebee engine is starting to lose its money saving feel

 

[MH Hawker]

Re: Problem pull starting a 2 stroke mercury 35hp '89

To start off, its a boat motor, their is no free or cheep. I do have a starter wiring for a 96 model that may help you out. It may not be exact though. You didnt say if its a tiller steer or a full remote so here is both and you click on the pic to make it bigger to see it.