Odd OMC 1.6 1 Cyl. No fire at high RPM's

[ReelPotential]

1985 OMC seadrive 1.6 115 HP. Great spark on all cyl, All getting fuel, compression right/top-90, right/bottom 90, left/top 75, left/ bottom 85. Idles fine and revs up fine in neutral. Under a load it boggs down badly. Upon removing spark plug wires one at a time to detect a missing cyl, all but the left/bottom cyl nearly stalled the motor. The left/bottom had a very small drop in rpm, at higher rpm's no difference is heard at-all, when removing the plug wire. Boat was running on a plane when this suddenly occured, Cant seem to diagnose the problem. I have changed the coil to that cyl and its is getting plenty of spark and fuel, it also has better compression than the cyl above, which has less. Im lost. Hoping some one here might have an idea. Thanks in advance

 

[ReelPotential]

Re: Odd OMC 1.6 1 Cyl. No fire at high RPM's

Anyone?

 

[tx1961whaler]

Re: Odd OMC 1.6 1 Cyl. No fire at high RPM's

Did you change the spark plug?

 

[ReelPotential]

Re: Odd OMC 1.6 1 Cyl. No fire at high RPM's

Yes, I changed the plugs, wires and coils. The cylinder has, spark, compression and fuel yet still wont fire. I am totally baffled.

 

[ReelPotential]

Re: Odd OMC 1.6 1 Cyl. No fire at high RPM's

Okay been doing a ton of reading through old posts on here with similiar problems, and have found that many had to do with a carb issue. So i will try tommarow a fuel and oil mix straight into the carb on the side I am having the issue on. I just figured that both cylinders would be acting up if it was a fuel issue.

 

[ezeke]

Re: Odd OMC 1.6 1 Cyl. No fire at high RPM's

Why don't you go ahead and pull the port cylinder head and see what is going on in there?