6 hp Sea Horse-75 wont start after repair.

[andm]

Working on a 6 hp Sea Horse- 75 (model # 6RL75R) for a friend.
It has been standing unused for years and one piston was seized due to headgasket damaged and water had leaked in.
After a 2 weeks tratment with lubrication oil and carefull knocking with protection plate on the pistons I finally manage to get it free and moving.
Now it have new headgasket, cleaned carb with new float and the plugs are sparking.
But it wont start, not even ignite !?
Anybody have any ideas ?
Could something at the ignitions settings have been changed due to my treatment or ?

 

[Gus-71]

Re: 6 hp Sea Horse-75 wont start after repair.

Hi!
Have u checked the compression ?

Gus

 

[andm]

Re: 6 hp Sea Horse-75 wont start after repair.

No, I will do that tomorrow.
Do You think the piston rings could have been dammaged ?

 

[boobie]

Re: 6 hp Sea Horse-75 wont start after repair.

Your spark should jump a 1/4 " open air gap on a spark tester. Spark plugs mean nothing.

 

[andm]

Re: 6 hp Sea Horse-75 wont start after repair.

Will get me a compression tester tomorrow.
But I just noticed that the sparkplugs seems to be dry eventhough I have cleaned the carb, could it be somthing wrong with the fuelpump ?
I squezed the bubble on the tube and petrol was flowing throw the pump, but might a mebran or so been "glued" after years of non use ?

 

[AlTn]

Re: 6 hp Sea Horse-75 wont start after repair.

the diaphram rubber may be cracked and stiff in the f/p, but the real test will be the compression test to determine the next course of action

 

[andm]

Re: 6 hp Sea Horse-75 wont start after repair.

Oh **** !
Checked the compression top cylinder was almost dead and botton cylinder 70 psi !
Seems like it is more failures then the headgasket that i changed ?
Checked the compression on another johnson 6 hp and got about 100 psi on both cylinders.

 

[andm]

Re: 6 hp Sea Horse-75 wont start after repair.

Could it be some problem with the leafplate assy ?

 

[AlTn]

Re: 6 hp Sea Horse-75 wont start after repair.

not as far as the compression readings are concerned

 

[andm]

Re: 6 hp Sea Horse-75 wont start after repair.

Compression was allmost 0 on the topcylinder and 70 psi on the botton cylinder, broken headgasket has been changed.

 

[Tim Frank]

Re: 6 hp Sea Horse-75 wont start after repair.

Are you saying that you have changed the head gasket a 2nd time, or are you referring to the change R&R from post #1?

 

[andm]

Re: 6 hp Sea Horse-75 wont start after repair.

No only changed once, sorry for being unclear I just repeted what I had done.
I just cleaned the surfaces and assebmled the new gasket. Are You supposed to add some floating gasket as well ?
I will take it appart and see if I fribbled and there are some old gsket leftovers.

 

[andm]

Re: 6 hp Sea Horse-75 wont start after repair.

Took the head off and grinded the head (on a flat surface) and insured me that it was flat and clean. Re assambled it, but the comression result is still the same.
Any ideas what to check or do ?
Piston rings or ?

 

[Gus-71]

Re: 6 hp Sea Horse-75 wont start after repair.

Could u see if the cyl walls are scorched?
Maybe the piston rings are stucked because they are so rusted and have no tension at all.

Lycka til farbror Melker
Gus

 

[andm]

Re: 6 hp Sea Horse-75 wont start after repair.

Cyl walls looks ok, but as the lower piston was seized when I start working on this, and it has been standing in a boathouse unused for 15 years, then yes I think You can expect the rings to be stucked, rusted and without tension.
So it seems like I have to take the pistons out for inspection, anybody know where I can find instructions to do that in the most efficiant way ?

Tack s? mycket fr?n oss p? Saltkr?kan

 

[Gus-71]

Re: 6 hp Sea Horse-75 wont start after repair.

The best way is to buy a manual, you can search here at this forum, youtube.....
but at this link you can at least see the all the parts in a exploded view.:

marineengine.com/parts/johnson-evinrude-parts.php?year=1975&hp=6&model=6R75R.

I'm afraid if the motor was running in saltwater U may have a rusted crankshaft as well.

Helsning fron alla oss p? katthult.
Gus