1975 Mercury 1150 No spark

[FullCircle]

I bought a 1975 mercury 1150 inline 6, I took it home and decarbed it, checked spark on all 6 , good spark.

I was thinking it was not getting fuel, so I had the fule pump cleaned. I also replaces some of the lines and worked with the carb being cleaned. I put it all back together and low and beholdit woould not run. I fuond it has no spark.
After looking around, I did see that the switch box goes bad, so I found one on ebay, had it shipped. I replaced it exact part number. still no spark. I am checking the plugs as well as the coil wire. I have used a multimeter to check the voltagel and I am getting a good 13 to the switch box, however, I cannot see any activity on the coli wire coming off. How can I test the wires from the distributer? any help here?

 

[Clams Canino]

Re: 1975 Mercury 1150 No spark

Step 1

You need your 13 to the RED and also the WHITE terminal on the starbord side of the switchbox when the key is set to ON.

-W

 

[timmathis]

Re: 1975 Mercury 1150 No spark

Check that trigger next.
Here is a good troubleshooting guide that may help. Get that spark back.
Good luck, Tim

P.S. if you need some help just ask Clams he is the inline man. Top of the line....

 

[FullCircle]

Re: 1975 Mercury 1150 No spark

where is the good trouble shooting guide?

 

[FullCircle]

Re: 1975 Mercury 1150 No spark

I have 13 volts to the red and white on the starboard, also to the on the port with the key on and also to the brown on the ports side. Can I turn the motor over and look for any kind of interittant signal for spark coming from the distruber, then look for this signal on the starboard green wire to the coil to see if the switch box is good?

 

[timmathis]

Re: 1975 Mercury 1150 No spark

http://outboardparts.com/mercury/miscellaneous/troubleshootinghelp.htm

Click on link above or copy and paste for troubleshooting guide. Or you can go to www.outboardparts.com Then click on mercury then click on troubleshooting then click on print guide.
Sorry it did not post before. Tim

 

[FullCircle]

Re: 1975 Mercury 1150 No spark

What is the difference between thunderbolt ignition and the standard? the switch box I got was from a thunderbolt and I have a standard ignition. Will this matter? I have a manual on the way, but is there an easy way to check the trigger?

 

[Scaaty]

Re: 1975 Mercury 1150 No spark

What is the difference between thunderbolt ignition and the standard? the switch box I got was from a thunderbolt and I have a standard ignition. Will this matter? I have a manual on the way, but is there an easy way to check the trigger?

" I have a manual on the way"..
Probably too late. The old Merc inlines need super care and good grounds. The trigger systems are ...lets put it this way..you need a Pro to look at it

 

[2cycle]

Re: 1975 Mercury 1150 No spark

If the Pros will look at it...which you may find to be an issue. I had the same problem about 5 years ago, and shops here didn't want to touch it due to the age of the engine and the astronomical prices on parts from Mercury. The solution for me was to buy a used distributor and then install and set timing. Replacing the trigger body new is much more expensive than a complete used distributor. You can find them on Ebay all the time and some vendors will at least guarantee that it will work when it arrives. Just a thought, if you run into hassle with the shops. They are easy to install if you are patient and have a manual.

 

[FullCircle]

Re: 1975 Mercury 1150 No spark

What is the difference between thunderbolt ignition and the standard? the switch box I got was from a thunderbolt and I have a standard ignition. Will this matter? I have a manual on the way, but is there an easy way to check the trigger?

" I have a manual on the way"..
Probably too late. The old Merc inlines need super care and good grounds. The trigger systems are ...lets put it this way..you need a Pro to look at it

 

[FullCircle]

Re: 1975 Mercury 1150 No spark

Say I just happen to have a distributer plus two other 1150 motors also.
My first question would be But why would not grouding blow the trigger? would it not blow the switchbox? I probably turned the motor over without the battery by the rope, or did not have a good ground. I am assumming it is the switchbox.
I have the manual but it does not say how to see if the switch box is working. I also have seloc onlin.
Can someone out there tell me with a multimeter how do I know if the switch box is working? Owning three of these motors, this info would be helpful.
This way I can divide and conquer, swithc box or other.
I know i have 13v to the bottom wires on the portside, and 13 volts to the bottom wire on the starboard, what do I look for in the other two wires coming off the the distrubuter ac/ dc and volts peak volts? I know I should be looking for ac of the ignition coil wire.
Thanks for the help guys, there has to be a way to test the switchbox, I just know it...

 

[Plainsman]

Re: 1975 Mercury 1150 No spark

This is from clams who helped me last year:

The test you need is the switchbox test. It does not go in to detail here. But it is in the wiring diagram. You disconnect the trigger wires and then you put a jumper wire from the Brown to the white terminal on the box. Then you arc the black wire to ground it should spark every time. If the switchbox is good. That will mean the trigger is bad. You need to double check and make sure what wires to jump per to your switchbox #. I cant hardly read it on my monitor. It is blurry.


do you have 12V to the red terminal on the switch box?

do you have 12v at the white terminal when the key is turned on?

MERCURY BATTERY-POWERED CDI SWITCHBOX 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).


Disconnect the mercury switch (kill switch)

DISCONNECT 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. Jumper 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.

 

[FullCircle]

Re: 1975 Mercury 1150 No spark

super super super! I will test it and get back to you.

 

[FullCircle]

Re: 1975 Mercury 1150 No spark

Well, I have good spark, must be the trigger, will what a shame, I hear these are difficult to replace, I am sure that I would have to retime the engine too? If I replace the whole distributer?