1973 85HP Johnson top end power loss

[Seejay]

I bought a 'new' boat/motor and wanted some advice on the '73 Johnson 85HP V4. (85ESL73).<br />It seems to lose power at the top end. RPM will go to 3,300 at about 2/3 throttle and drops to 2,800 at full throttle and slows down. Does fine at low/idle speed and out of the water. Something isn't right...looking for advice. Put new fuel in before running, checked out filter, plugs. Firing on all cylinders etc. Haven't checked compression yet. Any thoughts? Timing? Linkage?

 

[Reel Appeal]

Re: 1973 85HP Johnson top end power loss

Is the ignition timing being advanced when your above 3300?Check linkages to advance rod under flywheel.Compression should be ok if motor starts easily.Dirt or junk in the carbs.Are the coils original?They may be breaking down at high RPM's...

 

[Seejay]

Re: 1973 85HP Johnson top end power loss

Thanks. I will check linkage as advised and timing. Carbs seem very clean, although I haven't completely removed. Only took off cover to inspect. I'll also check compression. Thanks for tip on possible coil problems.