compresson on 10 hp?

[pikefisherman]

what is acceptable compression on 1962 10 hp ,I have 65 psi on both cyl. with cold motor, is this ok, also how do I set gap for fly wheel and magneto? I have new points set to 0.20 and new coils but one set of points are not firing.

 

[HighTrim]

Re: compresson on 10 hp?

Are the coils original or replaced>?

Usual issue is dirty points, even when new. Dip a business card in acetone and run that through to clean.

65 is low on an accurate gauge for a 10hp. Most are in the 85 to 105 range. Possible decarb to bring it up once you get it running if it is just carbon issue.

 

[eavega]

Re: compresson on 10 hp?

Don't have the answer to the gap on the magneto, but I can tell you that 65 PSI is acceptable on a 10 HP. I had a 1962 Johnson 10 HP outboard that ran just fine with 60 PSI.

Rgds

Eric

 

[HighTrim]

Re: compresson on 10 hp?

Sorry forgot to comment on the air gap. You want the edge of the laminations flush with the mounting boss. A coil ring is ideal, but if you do not have one, run your nail up the mounting boss, and pull the coil out so that your nail wont catch. You want it as close to the magnets as possible, without touching. If they are too far in, spark will be weak. Too far out, and they will hit the magnets.

 

[dkonrai]

Re: compresson on 10 hp?

i had a 59 that had 60 pounds something about a relief so it pulls easier? motor ran outstanding tho. i could slow idle that motor for days. so im gonna stick my neck out and say 65/65 is pretty darn good.

as for spark, did you change the coils too? and spark wires? basic ignition system, coils, points condenser, spark wire/plugs and the carb is like a tin can with a hole in it. do the coils have cracks? what color is the coil?
dino

 

[boobie]

Re: compresson on 10 hp?

The coils should be flush with mounting base on the mag plate. A wide blade screw driver or putty knife will do it.

 

[pikefisherman]

Re: compresson on 10 hp?

Thanks: Every thing checks out except the dirty, points I think High Trim has a idea I remember dad telling me that points can be dirty , out of box, even new I'll clean and let you know.

 

[kfa4303]

Re: compresson on 10 hp?

This may help.


Johnson

 

[pikefisherman]

Re: compresson on 10 hp?

kffa4303 :Thanks Great reading! I think now I have fuel and plug trouble ,cleaned points and the old girl ran great then started spit and sputtered , the plugs were black and wet will change plugs and gas and try again. When the motor runs it runs like a new motor! I hate to give up on her I think she still wants to go fishing. ,

 

[kfa4303]

Re: compresson on 10 hp?

Try manually squeezing the primer bulb when the motor starts to die, if it picks up again, that means your fuel pump is probably bad. If that doesn't seem to help, you may have an air leak somewhere in the line. Also, make sure the brass nut the idel needle passes through is snugged down as well. It can sometimes back out due to the vibrations of the motor.

 

[oldboat1]

Re: compresson on 10 hp?

As above, if the gland nut on a carb needle rattles loose, the engine will run increasingly richer -- may give you the conditions you describe. Your carb may need disassembly and cleaning before it can be dialed in, including the chamber above the low speed needle.