1969 Merc 350 hard to crank

[tsutter]

Hi all:

Had a motor in storage for last 2 years. Someone comes along and wants to buy it. But they want to see it run first. Hook everything up to gas and battery, but when key is turned, the engine cranks VERY slowly (about 1-2 cranks per second). Take one plug out and seems to crank a little better. Take both plugs out and cranks no problem. Could the cylinders be gummed up?

Additional info: wire harness (mainly positive lead to battery is VERY corroded - wiring insulation has broken off in places; cracks in wire coating in other areas. Could this affect cranking?

Any and all help much appreciated. Thanks in advance.

 

[Fuzzytbay]

Re: 1969 Merc 350 hard to crank

Poor terminal connections will lead to slow cranking, so will a weak battery. I doubt it siezed sitting. Try squirting some deep creep, or similar product in the plug holes,and fix your battery connections up, then post back on the results.

 

[coolguy147]

Re: 1969 Merc 350 hard to crank

ya get some oil in the cylinders first. now if u stored it right it should start right up

ya those wires need to be replaced before anything can happen

 

[tsutter]

Re: 1969 Merc 350 hard to crank

Thanks again guys:

It was the battery. Got another one and it fired right up.

Terminal wires will also be replaced.

And thanks to iboats forums!