'70 Evinrude Triumph 60










Hooked the hose up to the motor flusher and started it in the driveway.


Runs fine until I get almost to full throttle then it starts to skip and a couple of times it has backfired.





Spark plug wires and all other wiring look real good, no dry, cracked insulation.





I'm planning on


1 Running some fresh gas with a can of Seafoam in with the oil mix


2 New spark plugs.





What would be the next logical step?
And is the Seloc manual any good for working on it myself?













 

I am no marine mechanic, but your plan sounds good.   Run the seafoam on the old plugs, then change the plugs.

Don't run the motor wide open out of the water! 2-stroke motors don't like being run at high RPM's unloaded. You are lucky it didn't "run away" on you and rev into the stratosphere ending in connecting rods protruding through the block. Also, the flushing attachment won't supply enough water at high RPM's and the pump will cavitate burning the rubber impeller.
If it starts easy and idled, it's time for a lake test. make sure it has fresh a fresh fuel/oil mix and take it to the lake.
Run it on the trailer first to make sure it isn't going to crap out on you 1/2 way across the lake.
How long has it been since the impeller/water pump has been serviced? How about the lower unit lube? Is it milky looking or burnt/black?
Let me know...I am a marine tech. IM is best.
KB in AZ
ETA–– the Seloc manuals are better than nothing..but not much. Look around for some Johnson/Evinrude "Carbon Guard". It is a fuel additive which helps dissolve carbon buildup on the piston tops. Those old "cross flow" engines had trouble with carbon building up on the piston top. This increases compression and eventually, when the compression gets too high, the engine will start detonating and will knock a hole in the top of the piston. This is also the reason I recommend using hi octane fuel in the crossflow engines. The higher octane will help prevent detonation.

if you let it sit you need to go through the carbs before you try to run it at speed then you risk running the engine lean. you can take the carbs down your self with that manual. they are that bad.

DUDE!!!  

Replace that Prop!!!  

It's on the list, along with another dozen things...