Can i do myself ? 72 115 Merc

[liebe722000]

I need to adjust throttle cable. Shop wants $ 170.00 . Dont have manual, can i do myself ? Also they want $ 85.00 to check ignigion system and if it's a power pack, they want $ 300.00. Problem ? No spark from coil, am no good with checking electrical. Thanks Again RenoMark

 

[studlymandingo]

Re: Can i do myself ? 72 115 Merc

Adjusting the throttle cable should be a fairly easy task.

Investing in a good manual should be your first purchase. With the manual, you will be able to diagnose and repair most any problem with the outboard.​

 

[Chris1956]

Re: Can i do myself ? 72 115 Merc

Mark, For that motor to run it needs to have +12V on the red wire on the switchbox (in front of the carbs) at all times. and +12V on the white wire (same side as the red wire), whenever the key is in the run position. I recommend you check these first.

Here is the diagnostic procedure from Clams Canino:

MERCURY BATTERY-POWERED CDI TEST
FOR DISTRIBUTOR MODELS

This test is for the 332-2986 switchbox used from 1967-1978 on all the inlines.

This test assumes your coil is good (most all are).

DISCONNCT BATTERY

1. Turn off ignion
2. Disconnect all 3 wires on the distributor side of the switchbox.
3. Remove the HV lead from the coil to the center cap (remember it unscrews
from cap)
4. Reconnect that HV center lead to the COIL side only.
5. Position that HV lead about about 3/8" from ground (block, shrouds etc)
and find a way to hold it there.
6. Jumber the brown and white terminals on the dist. side of the switchbox
together.

RECONNECT BATTERRY

7. Check that you have +12 V at red terminal.
8. Turn on ignition and verify +12V at white terminal (on red terminal side)
9. Touch the black terminal to ground - unit should cause spark each time
you touch ground.

If that passes and it won't fire at all, suspect the trigger

 

[liebe722000]

Re: Can i do myself ? 72 115 Merc

Thank You Very Much. That will be very usefull. Mark

 

[Scaaty]

Re: Can i do myself ? 72 115 Merc

Throttle cable is easy.
Caution here..the lever nut is a Nylock 1/4-28 (NF). Have a spare..in fact, have two, toss one down in the cowling for the water Gods to be satisfied and get it over with!)
Anyway, take the nut off the throttle lever that holds the cable. Unhook the convoluted plastic retainer thing in front just where the cables come in the housing. Throttle cable in the top one.. pull it out to get at the barrel nut.
NOW (two people needed here, one to start the motor, other to hold lever pressure on the throttle so its closed against the idle stop screw. DO NOT LET IT GET AWAY and over rev!!. In/out on the idle until its where ya want it (700 rpm). Shut it down.
Now, this is important. Adjust the barrel nut so that when you put the cable screw back through the lever, its applies pressure to hold it against the idle screw, or it will idle to high. And back off the nut a 1/4 turn or so (shift lever nut too)...they need to have some slack.
PS. Make darn sure you ONLY touch the idle stop screw. You touch the timing screw, and I will personally come over there and beat ya up...!!