Tachometer not working on my pontoon. 2 cycle 50 hp mercury engine

Any outboard 2 cycle after 1965 will run on 50:1 approx 500ml or half a quart per 5 gallon tank.

many mercury motors use a rubber mounted prop on the shaft which is a sacrificial idea to prevent gear box damage and prop damage in with under water objects
what you suggests indicates that at certain load situations that rubber has failed and allowing the shaft to turn but is not driving the prop as required
It is driving just enough to give you steerage to get home

With modern oils all 2 cycle engines (if it is a 2 cycle) can be safely mixed at 50:1. Most auto parts stores will carry the proper 2 cycle oil for outboard engines.

Need some more info to answer your question. Will the motor not turn over at all or will it turn over and just not crank up?

2 cycle, 50:1

Quiksilver marine dealers !

If it's a machanical tech check for a broen line from the engine. If electric check for + voltage to the tech if ok tech if bad

this is just one of many carbs on a 50 hp merc


http://www.boats.net/parts/search/Merc2/Mercury/50%20(3%20CYL.)/9385911%20THRU%209469199/CARBURETOR%20ASSEMBLY/parts.html

if this isnt it just go to boats.net and check your modle number
good luck

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