Hey Big Four need help!

[Ron.M]

1976 Johnson 85hp v4. Mod. 85EL76d, Ser. # j4557029. When setting the timing on this motor what should the timing reading be for this motor at Idle speed? Thanks! Ron.

 

[Big Four]

Re: Hey Big Four need help!

Thats a tough question because no one uses that reading to do anything with. My guess would be 0 degreesBTDC. What makes you think this engine needs timed? Unless you changed it there is noway for it move by itself..<br /><br /> Timing it has to be done at 4500rpms under a load. First you need to set the pointer on the flywheel for exact top dead center on number one piston. The use a little white paint on the flywheel degree mark you want to set it at. Run her up to rpm and hit the flywheel with the timing light and get a reading. The adjustment screw looks right at you under the left side of the flywheel. One turn equals one degree. So if your 5 degrees off turn the screw 5 turns. Knowing this you don't need to try to adjust it while running, you can slow down make the adjustment then bring her back up rpms to see if you are where you need to be. Unless you have a super hot timing light doing this at dusk makes it lots easier to see your flywheel mark.

 

[Ron.M]

Re: Hey Big Four need help!

Hi Big four, I was messing around with the throttle and timing screw before I found out what they were,trying increase speed,but not knowing what I was doing ,nearly risked this motors life with my lack of knowledge.By the way theres an inline fuse conection on the side of the motor, someone put tinfoil in it instead of a fuse, it looks like it should have a short tube type fuse,what is this fuse for? and do you know what size it takes? Thank you for your help. RON.M

 

[Big Four]

Re: Hey Big Four need help!

That fuse is a 20 amp and it's the main ignition circuit. I forget the letter designation on it but your right it's little short one. Pick up couple extra and tape them to the wiring harness under the engine cover.<br /><br /> Yes, you don't want to run that engine out of time very long. To much advance and you'll melt pistons. The older OMC's like that were sent thru with the timing slightly retarded for breakin, then at the 20 hr check the dealer advanced it to were it should live. I forget the exact degrees it's suppose to be at, but 26 BTDC sounds about right.

 

[Javlin85]

Re: Hey Big Four need help!

Big Four is right, I have the same motor and the sticker on the top says 26 degrees. The fuse in mine is a 25 AMP shorty, and I'm pretty sure that it's the origional factory fuse. We've owned this motor since it was new.