New to me 1975 mercury 850

[aburke120]

Bought a 90 Sea Nymph ss195 with a non running 1975 merc 850. I turns over, but has no spark. I knew this when I bought it, and have been waiting for a factory repair manual to do any work on it. The manual came in the mail yesterday. The motor has a remote hydraulic lift that sits under the splash pan, and only clicks when the buttons are pushed. The manual doesn't have any information on this remote unit, .The unit will click when I push the up/down button, and I can raise and lower the motor by hand after turning the relief valve, Anyone know where I can get any information on this remote unit. Thanks

 

[Chris1956]

PTT units on that vintage Merc 4 cylinder motor are rather rare. However, it is the same PTT unit as on an IL6 from 1977 and a few years newer. Parts diaghram can be found on the crowleymarine web site under '77 Merc 115.

I would think a service manual for the same motor might have PTT info as well.

First test is to bypass solenoids and apply power directly to PTT motor. If she doesn't spin, there is your issue. An electric motor shop might be able to help.

 

[aburke120]

Thanks Chris1956 I'll look into it.

 

[aburke120]

Units on crowleymarine web site don't look the same as what I have. Mine has 2 hydraulic hoses on each cylinder, and the cylinders are outside of the motor, not underneath. Pump reservoir and wiring are under the splash pan. When this rain quits I'm going to jump the solenoid, and see if the motor runs.

 

[Chris1956]

The 1977 Mercs have the PTT pump/reservoir in the boat, 4 hydraulic hoses and two trim cylinders, outboard of the transom clamp. Not sure what you were looking at....

 

[aburke120]

guess I was looking at it wrong. The 115 breakdown shows what you mentioned, the hydraulilcs I guess I'm looking for more, tomorrow I'm going to bypass the solenoid, and go to the motor and see if it even runs. This boat has a key switch on the dash and one on the throttle control. Not sure what each one is for.

 

[Chris1956]

Dash keyswitch is probably for an older OMC motor, or some Rube Goldberg setup to bypass something in the MerControl.

A 1975 Merc 850 will have a battery powered CDI ignition. It will also have crumbling engine wire harness. That will need to be replaced.

Jumper the starter and test compression, ign off. If the compression is even, proceed to the ign test. It will be found on the CDIElectronics web site. You can jumper the switchbox from the battery, to bypass the MerControl.

 

[aburke120]

crumbling engine wire harness is an understatement. I worked as an electrician for 40yrs and have seen messes like this one. In my eyes, it's not bad, I can make it spin. It won't look pretty but it will work. thanks for the info