High RPMS instant rpm drop to zero and back

[bluechevyy]

I have a 2005 mercury 115hp 4stroke. Runs great and all of a sudden at about 4200rpms it will hesitate for a split second and drop to zero rpms and back to 4200rpm within a second. Then run normal for a short distance. Happens maybe once a minute or so.

Definately seems electrical and not fuel related. No hesitation or loss of power like bogging just a split second instantaneous hesitation.

Any ideas please help. I've search for common threads and can't find any similar.

Thanks in advance

 

[bluechevyy]

Please help with any suggestions

 

[alldodge]

I would look for a loose connection, maybe @racerone may have other ideas

 

[Chris1956]

That could be an indication of fuel delivery issues, if it happens regularly at a given RPM. Run it on a portable tank, with a short 3/8" ID fuel line, and see if it continues.

 

[Texasmark]

You didn't specify a lot of details but in addition to Alldodge's comments, you may have corrosion on some mating electrical connections. Wouldn't hurt to cycle the interconnecting joints several times to rub off any corrosion and ensure that you are getting constant conductivity in the joint and while doing so, check the integrity of the wiring/connector plug/socket interface. I agree that a fuel problem wouldn't be an instant 1-0-1 situation since fuel, being a liquid mass, has to have time to move from point A to point B.