Mercury problem

captdoral

Recruit
Joined
Oct 17, 2010
Messages
1
We own a 1982 doral with a 1982 70 hp merc still running well. However at medium rev(around 15-30mph) sometimes the motor will rev down a bit than back up cycling like that for a while.However when we slow down the problem stops. This has been happening since 2009.The motor has had a "starting component" replaced and has been serviced every year. If you could suggest anything it would be a big help
Thanks Alex
 
M

Maxz695

Guest
Re: Mercury problem

Check Harness for loose connection to the coils check the spark plugs wires are tight from the coil to them. Sounds more like a fuel problem other than an electrical problem. Has the fuel pump or crab been rebuilt in the last few years. A sticky float will restrict gas then let gas pass when shocked loose. a bad valve seat can dump extra fuel and cause it to putter. You say this happens only sometimes not all the time. Dirt in the float bowl can do this
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,030
Re: Mercury problem

Alex, squeeze the primer bulb and see if the issue goes away. I suspect a shortage of fuel at those higher RPMs. If that cures it, likely a fuel pump rebuild is in order.
 
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