1967 thunderbolt merc 800 outboard no spark

[Ja31484]

Boat set for a couple years ran when it was put away now it has no spark to the plugs or to the coil. The serial number is 2561378. I appreciate any help. thanks guys

 

[emckelvy]

The serial # indicates that your motor is a 1969 model, which makes sense since no 800 models were produced in 1967.

Some of the early 80hp models had a strange ignition, so it would help if you'd post a picture showing the distributor & its wires, along with their connections to the switchbox. All that is on the Port side so one shot should do it.

Once we figure out what ignition system you have, we'll be able to help you troubleshoot.

HTH.........ed

 

[Ja31484]

Port side

 

[Ja31484]

starboard side

 

[merc850]

This could be a trigger problem or a power problem; the trigger test is on this site - to test the power attach a negative lead of a 10 to 20v voltmeter to a ground on the engine and with the key to run position touch the + lead to the red and then white terminals on the starboard side of the switchbox, you should see 9-12v.
The white terminal is the on/off power.
It looks like the switchbox starbrd leads have been spliced there might be corrosion there.

 

[Ja31484]

Im thinking that the red had power and the white had no power at all to it even with the key on but ill double check it when i get off work and post the results. I appreciate your help.

 

[Ja31484]

I guess I would also add that it does turn over when the key is turned... just doesnt spark.. if that changes anything.

 

[emckelvy]

Here's the "official" testing procedure:

"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 (problems with CDI coils are rare).

DISCONNECT BATTERY

1. Turn off ignition;

2. Disconnect all 3 distributor wires on the Port side of the switchbox (and the ?mercury switch? if present);

3. Remove the HV lead from the ign coil to the center of the dist. cap (remember it unplugs from the coil and unscrews from the cap);

4. Reconnect the HV lead to the COIL only;

5. Position the free end of the HV lead approx. 3/8" from ground (block, shrouds etc), and find a way to hold it there;

6. Jumper the brown and white terminals on the dist. side of the switchbox to each other.

RECONNECT BATTERY

7. Check that you have +12V at the red terminal (even with the ign off);

8. Turn on ignition and verify +12V at the white terminal (same side as the red terminal);

9. Ground the black terminal on the distributor side of the switchbox - this should cause a spark each time you touch ground.

If you get spark with the distributor bypassed, and it won't fire with the distributor connected, the trigger is bad and the entire distributor housing assy must be replaced.

If you get no spark using the test, the switchbox is probably bad. In that case, be sure to check for correct power on the switchbox, check all connections, and check the coil's resistance to make sure it's OK."

G'luck!............ed

 

[Ja31484]

What If im not getting any power to the white terminal with the key on? do I have a loose wire somewhere or is the switchbox just shot?

 

[merc850]

Either the key switch is broken or you have bad connections if you have a test light check the electrical connectors
for power.

 

[Ja31484]

Thank you I now have fire to the spark plugs found a loose wire appreciate all the help

 

[merc850]

You're welcome.

 

[mopman]

I just bought the same motor, picked it up off craigslist, was told that it was in running condition, and of coarse it's not. Most of the wires are not hooked up at all, some areasy broke, but I can figure all that out. What bothers me right now, is that when I connect a battery charger directly to the starter, it spins clockwise, and the bendix does not enngage. Is it spinning backwards, I know most the time you would say that there's a bad connection and the starter just isn't getting enough juice, but I'm hooking a battery charger directly to it..... any advise or suggestions would be greatly appreciated.

 

[merc850]

Positive battery power to the side stud and negative to the case (ground).
See last pic. above.

 

[Ja31484]

So I've got spark to the plugs now and I've got new fresh fuel but it still isn't starting.... Any suggestions on where to go from here?

 

[emckelvy]

Here's the standard starting drill for most old Mercs:

Pump the primer bulb until it's hard and then a few more times;

give it a lot of fast idle until you know what it needs to start, but be ready to shut it off fast (or pull back the fast idle lever) before it overrevs;

turn ign "ON", push & hold choke button (make sure the choke shutters close completely); turn key to "Start", release to "ON" when it comes to life.

Release the choke button, but be ready to hold it down again for a second or 2, if the engine wants to die.

Whatever you do, Don't use starting fluid. Bad for the innards! You can put some 2-stroke mix in a spray bottle, then spray a bit into each carb. If it doesn't kick after force-feeding the carbs, it's either flooded or has other issues.

You may need to verify the belt timing is sat, other adjustments ok, etc. Here's a link to the generic procedure for making those adjustments:

http://forums.iboats.com/forum/engi...ing-and-sync-of-merc-inlines-to-1988?t=168855

HTH..............ed

 

[Ja31484]

Its running, thanks guys now ive got some tilt/trim problems ill post a new topic for that.