I have been trying to get this issue resolved for about 3 months now and can not figure out what it could be.
I have had a rebuilt lower unit installed.
Carburetors rebuilt.
Changed from metal to plastic gas tanks.
I purchased the boat in July of this year. Took it for a good run on the CT river before I brought it down. It ran well, but if you hammered on the throttle it would stall.
2 weeks after I brought it down (had taken it to Murray twice and Moultie once) I blew the lower unit and had a rebuilt one installed.
At this point it still had the stalling issue when you hammer on the throttle and figured it was a carburetor issue so I took it in to have the carburetor rebuilt.
After that it ran like a champ for about two weeks. Top speed increased from 29 to 35mph.
1983 Evinrude ELCT70 Motor
1983 Grumman 5.0 Sportsman (side console)
Then I started having issues where when running at top speed for about 5 minutes the boat would start jerking like I was moving the throttle up and down. So I would slow down a little and it would run for a little longer then start jerking again. I come to a stop and increase the throttle to about 3mph, but the vibrations of the motor shake the whole boat. If I give the motor anymore than a 1/4 throttle the motor stalls.
The motor fires up every time the key is turned. It will idle like a champ.
Please help. I have already put 1400 into this motor.
Eric J Carpenter