85 40hhp problems

I have an 85,40 horse.I have gone through the thing about a year ago.It has run fine until last week.I had it out,and after it got warmed up,I gunned it.It ran about 2 minutes,ans shut down.I waited a minute,and it fired right back up,but ran rough.I got it moving again,but shortly it quit again.Same thing,over again.
Got it nursed to trailer.Got home,and checked compression.# 1 has lower than the other 2.they have 130 +-.When I redid this thing ,I had help from a mechanic from a marina.It ran fine numerous times until now.
Where do I start???

[99yam40]

Just like all motors you need fuel ,compression, and spark to run. check to see what you are missing when it dies.

Thanks,I did that as soon as I got it home,,,,the ducks can wait.Top cylinder is a lot lower from the others in compression.Other than that,it seems ok.
Any idea why the thing would just shut down?Loke I said,it restated,but ran real rough.I had to nurse it back to the trailer.

[99yam40]

like I said you need to see what is missing when it does not run. could be fuel problem or spark, I cant tell from here.
You said the Top cylinder is a lot lower from the others in compression, what are the numbers? You may have galled a piston from a cylinder running too lean, broke a ring, overheated, etc. you need to do some trouble shooting to see what is going on. Did it lock up when it shut down?or just die? Would it turn over?

Thanks for getting me in at least a general direction.It died,and would turn over.It was running fine,and it was like I just shut it off.On the compression,the top cyl.had about 15-20# of pressure.The other two had 120,plus or minus a little.

[99yam40]

That sounds like real bad news.
pull the head and see what you find.

Thanks,it's time for the Winter storage.I will get the furnace in the garage fired up,and see what I find.Thanks SO much for the direction.I will let ya know what comes of this"gem".