Engine RPMS drop by half when going into reverse

[Gangly]

Sometimes when I put the boat in reverse, the engine rpm's drop by half and the engine stumbles. If i take it out of reverse and put it back in, sometimes the problem repeats and sometimes it works perfect. When the engine does stumble, the drive is in gear, there is no noise, grinding, or roughness from the upper or lower unit, but the engine simply cuts its rpm's by half and stumbles until I put it back into nuetral. I adjusted the TMSC according to the OMC manual specs using the tools and everything is lined up correctly.

Ive heard that the ESA only works when shifting out of gear, but this sure seems like the ESA is activating when putting the boat into gear.

Any thoughts?

 

[Gangly]

Re: Engine RPMS drop by half when going into reverse

1991 Four Winns OMC 5.7 with Cobra Sterndrive

 

[Levinz11]

Re: Engine RPMS drop by half when going into reverse

Take a peak at the ESA switches while someone puts it into reverse. The shift cable can become old and sticky activating the switches at the wrong times.

 

[Gangly]

Re: Engine RPMS drop by half when going into reverse

Thanks for the heads up, Ill watch them closely while someone shifts for me.

 

[Levinz11]

Re: Engine RPMS drop by half when going into reverse

Or just unplug the ESA module and see what happens.

 

[HT32BSX115]

Re: Engine RPMS drop by half when going into reverse

Thanks for the heads up, Ill watch them closely while someone shifts for me.

You can also look at the "shift interrupter" and see if it moves enough to activate the switches when going into gear.

It should move a little but not enough to actuate the switches. If it does, it's taking too much "force" to shift into gear. That is usually due to a binding, corroded, defective lower shift cable, etc OR it could be a problem in the moving the shift dogs in the drive.

 

[Gangly]

Re: Engine RPMS drop by half when going into reverse

Thanks for the heads up, I appreciate it!