15hp 4 stroke question

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Guest

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MERCURY - ( 15 H.P. (2006 ))
Serial No: 1B281025 Model No: 1F15203FD

When i pull the cord to start my ob i can pull 4-6 times and then it gets really stiff and very hard to pull. Then once i pull it really hard it starts to pull normally again for about 4-6 pulls. When i compression tested it, that is when the compression jumped from about 50-100. What can that be? is it the starter/flywheel or i have engine damage? Thank you for the responses
 
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carholme

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Re: 15hp 4 stroke question

Have you lifted the manual starter assy off the engine and then rotated the flywheel to see if you still have the same problem?

Gerry
 
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Re: 15hp 4 stroke question

carholme said:
Have you lifted the manual starter assy off the engine and then rotated the flywheel to see if you still have the same problem?

Gerry
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No, i figured i will wait for warmer weather and see if it affects me in the bay. it ran very smooth in a bucket but i need to see it under load. You are right though i will need to kill all my problems. don't want to risk breaking down.
 
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racerone

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Re: 15hp 4 stroke question

It appears that you are turning the flywheel backwards , why is that?
 
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Re: 15hp 4 stroke question

racerone said:
It appears that you are turning the flywheel backwards , why is that?
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it is because I am an Idiot and will post a new vid in the morning. (showing off my newbie skills. But learning more and more about OB every day reading your answers)
 
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MH Hawker

MH Hawker

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Re: 15hp 4 stroke question

Looks like the normal compression stroke to me.
 
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Re: 15hp 4 stroke question

carholme said:
Agreed, looks like compression stroke but hard to tell. Here is a link to what is under the flywheel and if you feel that something is hanging up, you should remove it and see that nothing is loose in there.

Mercury, Mercruiser, Force, etc. - Flywheel - 13.5/15/15 BODENSEE (4-STROKE)

Gerry
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So you think i put it in the water under first so see if it is causing any kind of malfunction or you can tell theres something wrong? Doing a compression check i noticed once i get past that tough turn thats when the compression rises to over 100. What do you think it can be or is it acting normal?
 
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carholme

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Re: 15hp 4 stroke question

Well if it is on the compression stroke, that is when you are going to get the rise in compression, that's normal. If you are not hearing any strange noises, put it in the water, start it and see what it does. It is hard to say whether or not there is something wrong. Obviously the compression stroke is bothering you but if you don't have much experience with these engines, it may be normal and you just haven't experienced it before.

Gerry
 
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Re: 15hp 4 stroke question

carholme said:
Well if it is on the compression stroke, that is when you are going to get the rise in compression, that's normal. If you are not hearing any strange noises, put it in the water, start it and see what it does. It is hard to say whether or not there is something wrong. Obviously the compression stroke is bothering you but if you don't have much experience with these engines, it may be normal and you just haven't experienced it before.

Gerry
Click to expand...

I bought it this winter and never got a chance to test it. Wasn't even able to comp check it because my comp was a 14mm that fit on my 6 2stroke but i assumed it would fit on this 15 but it didnt. He ran it in the a bucket (took him a while to start it. he claimed it was first time start all winter. Pretty much he had to spray carb cleaner into the carb to get it going. It seemed to have run fine after that in the bucket and shifted nicely. I got it home and ran it in a bucket it seems to run fine and switched gears pretty nicely.) I guess the reason why i am so worried is because i purchased an outboard last year 15hp force 1987 (first ob purchase) and after doing research at home found out the bottom cylinder had no compression at all. Found a container couple blocks from my house and dumped it. 450+200 marina service which claimed it ran great. 100% my fault for not doing research ahead of time and trusting people on craigslist. Wish I kept that one and used it as a learning project. Sorry to bore you but that is my story
 
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carholme

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Re: 15hp 4 stroke question

You are not boring me. Everything is a learning curve and we all have to start somewhere. Unfortunate that you did not keep the other engine. As you say, it would have been a great learning tool.

Gerry
 
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