1.6 L OMC only running on 3 cylinders

[Trucker G]

I have a 1983 OMC 1.6 L it's not firing on the top right cylinder has 95 pound compression it's getting fuel it's getting spark what am I missing

 

[racerone]

95 PSI is low.------Perhaps a reed valve issue.

 

[oldboat1]

The Sea Drives were 2-strokers. What's the history of the motor and maintenance? Been stored?

[edit. 50:1 if premix. 100:1 was tried and abandoned in the '80s, so might be relevant.]

 

[Trucker G]

When I bought the boat it had a blown head gasket on the right side replace the head gasket clean carburetors new plugs fired right up seems to be running okay at home that felt like it was a little sluggish on the water pull the plugs out and they all look fine except for one which still look brand new

 

[oldboat1]

If only one is like new, suspect water intrusion in that cylinder. Repurpose a timing gun, and check each lead while running -- no flash, no spark.

For water, could be head cover warping or an uneven torque issue.

 

[racerone]

Clean sparkplug caused by ----No ignition -----No fuel -----No crankcase compression.---No cylinder compression take your pick.

 

[Trucker G]

I replaced both head gaskets! Compression 95 to 100 lbs on all cylinders it's getting spark and fuel! How can I check crankcase comp.

 

[Faztbullet]

How do you know its getting fuel??? Take a squirt bottle of fuel mix and spray in carb throat,if pics up its carb. Was the cylinder scuffed??

 

[Tim Frank]

I have a 1983 OMC 1.6 L it's not firing on the top right cylinder has 95 pound compression it's getting fuel it's getting spark what am I missing

How do you know it is getting spark to the bad cylinder? What was your test method?

 

[Trucker G]

Already tried the squirt bottle! As for spark I pulled the plug out stuck it in The Wire and cranked it over nice bright Spark

 

[Tim Frank]

As for spark I pulled the plug out stuck it in The Wire and cranked it over nice bright Spark

What I thought....
That tells you only that when you remove the plug and lean it against the block that the spark jumps about a 1/32" gap.
You need to make sure that it will jump a 3/8" gap in an open-air spark tester.

 

[Trucker G]

I found my timing light and every wire shows it's sparking except for that one cylinder???

 

[oldboat1]

May be useful to you. https://www.crowleymarine.com/johnso...cfm?mdl=OMHFN8 Order here at iBoats.

Might try switching coils to see if problem follows coil (=replace coil).

 

[Trucker G]

FIXED!!!! Coil was weak

 

[Trucker G]

Just want to say thank you to everybody that tried to help with my situation

 

[oldboat1]

glad you got it handled, Trucker! :thumb::thumb: