Merc 70HP

[escapade]

I've posted my project in the resto part of the forum, however also need some help with the motor, couldn't get an answer back from merc but the serial is 7192706, the motor needs a good overhaul i'm thinking, however has great compression and spins freely

heres a few pictures

http://s35.photobucket.com/albums/d195/viper_coleca/Boat/

 

[diaric]

Re: Merc 70HP

1982 canadian , what help did you need? ok, looked at pics, thats pretty rough shape. squirrels or mice?

 

[escapade]

Re: Merc 70HP

i'm thinking squirrels, just need to overhaul the motor and prep it to start, want to make sure not going to have any issues with it running once the boat is completed

 

[rocket937]

Re: Merc 70HP

sorry, I should of looked at the pic's first. May need a bit more than tuning

 

[escapade]

Re: Merc 70HP

this sounds like a dumb question but what would the mix be? does it need to be mixed with oil? kinda out in left field, at least now with a year I can order a repair manual,

how to do "fog" a motor??

 

[escapade]

Re: Merc 70HP

anyone? also to test run the motor, i'd need a battery installed, throttle cable working and obiviously fix the wiring, do i just hook up a motor flusher and pump water through it? or is it best to launch the boat for testing of the motor?

 

[AMD Rules]

Re: Merc 70HP

Must be mice...the woudl have had to enter throught the air intake holes in the silencer box. What a mess.

Be extra careful inside the intake openings behind the carbs. Those reed plates are very thin. The small round holes you can just see. Try not to damage them, or allow any debris to pass through them. We're you able to vacuum that cavity out if debris got in there?

Carbs look really rough. Likely urine damage, corrosion. The motor's exterior looks good.

Any pics of the ignition part of the motor? Did they chew the wiring?

Carbs need rebuilt for certian. No use even trying to run it before doing that. I'd replace all the fuel lines, and vaccum tubing as a minimum.

Fuel ratio is 50:1. Yes, it needs oil added to the gas.

You can run it on muffs, but I woudln't hook up the electrical connections yet until you see that all the wires are in good shape.

More pics of the left and right side of the motor will help to evaluate its condition. If the only made a home in the carb box, you might get lucky.

Before investing too much time, take the plugs out and squirt some wd-40 inside. Do a compression check on all 3 cylinders. You need to see good compression an all three before going any further.

I'm sure it will be fine, with some elbow grease.

 

[escapade]

Re: Merc 70HP

what will i see if i have good compression across all cyl?

also is there a step by step on how to test compression??

 

[AMD Rules]

Re: Merc 70HP

Have a peek here. Different motor, but the technique is the same:

TMD Video Chronicle Comp and Spark check

 

[UC]

Re: Merc 70HP

First NEVER EVER EVER PUT WD-40 IN A MOTOR I SEEN IT EAT THE VALVE GUIDES GET A SPRAY BOTTLE AND SQUIRT 2 CYCLE INTO CYLINDERS BEFORE EVER TURNING OVER SHEES

 

[escapade]

Re: Merc 70HP

Here is a walk around of the motor with the cover off, everything seems ok less some corrosion and a few chew'd wires, only hard part i can see right now is the bolt that was corroded right off

 

[escapade]

Re: Merc 70HP

full size images avail here --->http://s35.photobucket.com/albums/d195/viper_coleca/Boat/

 

[escapade]

Re: Merc 70HP

i posted pictures for others too see the condition of the motor, anyone want to comment on the shape of the motor, and the amount of skill needed to fix?

 

[AMD Rules]

Re: Merc 70HP

If it was me, I'd strip all the electrics off of it, including the flywheel, stator and trigger. Also those carbs need a complete overhaul, if not replacment entirely. Looks like mouse urine has corroded the carbs quite bad. If you're lucky it will clean up okay.

Clean up all the electrical items without using any harsh chemicals that could damage the insulation. Shine up the terminals to ensure good connections. Replace any wires that look damaged from age, or nibbling rodents.

Replace the fuel lines, and rebuild the fuel pump.

None of that would be very expensive, and can be accomplished by someone with a service manual quite easily.

Given the cost of a replacement motor...a little money spend now on this one could prove to be money well spent.

WD-40 is just fine to use as a test to free up the rings after a storage period or even as an aid to promote starting a motor which hasnt been run in a while... BUT... premix fuel or something like seafoam deepcreep is even better as was pointed out above. Wd-40 just happens to be handy, since it is usually close to my workbench. A simple squirt in the plug hole is all you need. I wouldn't spray anything into the carbs, other than pre-mix.