1999 50HP Johnson. firing on one cylinder.

[James R]

Comps 1-135. 2-125, Carbs cleaned and rebuilt. Sparks to jump the grand canyon. Flywheel not slipped.
#1 running #2 not running. Evidence of fuel on the #1 piston. #2 piston dry.Shot fuel with spray into carb throats. No pick up.
Rotating by hand. finger in plug hole #1 pressure good a little suck back after compression. Same test on #2 pressure good but a greater suck back after compression. I have never had a problem with reeds on any motor. Do I have one now?
Would like an opinion before I start tearing the thing down.
Thanks in advance.

 

[racerone]

Did this problem develop suddenly ?-----Reed valves have nothing to do with compression in the cylinder.-------Remove carburetors to inspect the reeds.------Could be the bottom crankshaft seal.------Possibly the cylinder sleeve rotated.

 

[James R]

Thanks for your prompt response. This is a motor I bought with a tilt trim problem. Fixed that with new seals. Routine service done. I mentioned the compression differences only as a routine outline. Didn't think about the lower seal possibility.
Will pull the carbs and take a look at the reeds. Lower seal failure in such a young motor was not in mind. However it could be,I suppose. If I get to the lower seal I will certainly discover if the sleeve has rotated in a complete strip down. Good point.
Thanks for the input, Most appreciated. Will let you know what I find.
Thanks again.