rpms just dropped outa nowhere

[roscoe]

so the engine kept running, was it making any noise? cranks, rattles, grinding noise?

 

[coolkook]

Yes engine kept running..sounded fine...at this point i think comp test is necessary to rule out or in the cylnders...then if comp is good i will look into fuel and or spark or timing ?

 

[coolkook]

Ok..ty for all who are following this thread i really appreciate it...the comp test results are good..all 140 to 150..so i think thats a good thing...so im leaning towards fuel or spark issue ?..thoughts

 

[Chris1956]

Check for spark on all cylinders. Watch for spark plug wire arcing to ground. If you have good spark, carbs are next for investigation.

 

[coolkook]

Sent it to mechanic..will update results in 3 weeks

 

[rk970]

This happened to my merc800, It had one bad check valve in the lower fuel pump.