68 40 hp electramatic issues

starcraft bahama · Aug 19, 2013

I purchased a 1968 starcraft Bahama recently, it has been in storage for 45 years! It has a 40 hp Johnson Electramatic. When I got it home I rebuilt the carb and fuel pump and it purrs perfectly! Changed the lower unit lube with type "C". Water pump pumps great. Rewired from just behind the harness to good wires forward as the insulation was falling off the wires. So... here is the issue....It shift perfect into reverse and forward, but when trottling up it jumps out of forward gear. After warming up it doesn't seem to do it as often if at all. The voltage meter doesn't move either I keepa battery tender on it when not in use. Is it wiring issues or voltage?

Daviet · Aug 19, 2013

Re: 68 40 hp electramatic issues

You could have a problem in the lower unit, but before you go there have you checked the drive pin and prop hub?

Oh, by the way, welcome to the forum.

starcraft bahama · Aug 19, 2013

Re: 68 40 hp electramatic issues

Thank you!! This sounds crazy, but the motor has about six hours on it.. Long story..I did pull off the cotter key and the pin for the prop are snug. I did have the lower unit changed at a marina. Any chance they put in the wrong lube.. I bought a multi meter today and will check the wiring to the lower unit.

Daviet · Aug 19, 2013

Re: 68 40 hp electramatic issues

You might check the prop hub to see if it is slipping, pull the prop and scribe a line across the prop hub and the body of the prop, install the prop and run it until it jumps, then check and see if the lines still match up. If the lines don't match, you have a spun prop hub and need to have it rebuilt.

starcraft bahama · Sep 4, 2013

Re: 68 40 hp electramatic issues

Fleet Admiral, your a genius! Scribed the prop hub and it is slipping. At the prop shop being re-hubbed.Thanks again!!

Tim Frank · Sep 4, 2013

Re: 68 40 hp electramatic issues

starcraft bahama said:
Thank you!! This sounds crazy, but the motor has about six hours on it.. Long story..I did pull off the cotter key and the pin for the prop are snug. I did have the lower unit changed at a marina. Any chance they put in the wrong lube.. I bought a multi meter today and will check the wiring to the lower unit.

I thought YOU changed the oil and used Type 'C'?
Also, a 45 year old water pump with the original impeller is an overheat waiting to happen.
I'd change it now.

Daviet · Sep 4, 2013

Re: 68 40 hp electramatic issues

Glad you found your problem, and it is a cheap fix too.

starcraft bahama · Sep 15, 2013

Re: 68 40 hp electramatic issues

Here we go again! I had both of my props re-hubbed at the local prop shop. Put her back in the water, open her up and away we went, for a little bit.. The motor seems to kick out of gear. You can increase the rpm's slowly and get to about 3/4 throttle, before it will jump out. Once your up to a nice cruising speed it will run good. Any thoughts?

Tim Frank · Sep 15, 2013

Re: 68 40 hp electramatic issues

Daviet said:
You could have a problem in the lower unit, but before you go there have you checked the drive pin and prop hub?....

Looks like you are going to have to open it up and see what is going on.

boobie · Sep 15, 2013

Re: 68 40 hp electramatic issues

Sounds like an intermittent electrical connection or a bad hub and spring.

F_R · Sep 15, 2013

Re: 68 40 hp electramatic issues

Cavitation???? Is the motor mounted high on the transom?

starcraft bahama · Oct 15, 2013

Re: 68 40 hp electramatic issues

so........... I rebuilt the lower unit, bearings, seals and coils. The old coils had bare wire showing. I also replaced the water pump while I was in there. The hubs and gears all looked good. Got her all back together, put her in the water and took off just perfect. After 20 minutes or so, I throttled back and then accelerated to full throttle, started to plane and presto it starts to jump
out of gear again. Is there a switch in the throttle that could be bad? I had the prop rehubbed also!

boobie · Oct 15, 2013

Re: 68 40 hp electramatic issues

Read post # 10 again.

68 40 hp electramatic issues

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