Help with 1976 mercury 1150. No fire

Joined
May 24, 2010
Messages
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I am new to this so please bear with me. I have a 1976 mercury 1150. I was out fishing one evening when while on my way back to the dock the motor bogged down and died like it was starving for fuel. I could get it running but had to keep the fast idle up when i engaged the prop to get the boat loaded on trailer (tank still had about a fourth of tank). I took it back to the lake after filling up the tank with fresh gas and oil 50:1. The boat would not start. I had fuel getting to the carbs but t acted like it had no fire. When I got it home I checked for fire on the plugs with a spark gap tester. As suspected no fire. I have made sure the batteries are charged and have tested the volt on the side of the switch box Red wire had over 12v constant. White wire had over 12v with key in on position and from 9 1/2v to 10v when tryin start.
I placed the red lead from volt meter on the green wire to coil and grounded. No voltage was indicated. Did I properly check to make sure I had voltage to the coil from the switchbox? I have searched for testing procedures for the switchbox, coil, and distributer but have been unable to find the procedures. This may sound funny to some but I have learned more in the past 4 days about boat motors than I have ever known. Most of my knowledge has come from this forum. About all I have read on this sight has shown that there is alot of very knowledgable people out there that are willing to help those of us that know very little. Any assistance I can receive is greatly appreciated. Also does anyone know of good web sites and parts dealers for this age and type of motor. Again I appreciate any and all help. Thanks Rick
 

Mi duckdown

Commander
Joined
Apr 14, 2007
Messages
2,575
Re: Help with 1976 mercury 1150. No fire

I can tell you one thing. If you plan on keeping that year motor, and there is nothing wrong with that engine. Buy ONLY a OEM merc service manual. Get your serial no. before hand. Those other manuals, clymer,seloc are junk. I see them on ebay all the time for 30 bucks.
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
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15,931
Re: Help with 1976 mercury 1150. No fire

Check the distributor belt to see if broke,no spin ,no fire. If ok, check voltage on brown terminal of pack(trigger side) as it must be a least 9.5 VDC. If thats ok jump the brown & white together and turn key on, take a jumper wire and ground one end and tap the black trigger terninal and it should tire each time. If so pack is good and trigger has failed. The biggest thing that kill these are removing or loose leads while engine running.
 
Joined
May 24, 2010
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Re: Help with 1976 mercury 1150. No fire

Faztbullet

Thanks. Don't laugh but the distrubutor belt that is under the fly wheel just above the distributor right?
If so it looked like it was in one piece. As for the testing for voltage on trigger side I will do that either on lunch today or after work. I'l let ya know how it turns out. Thanks again for your help.

Rick
 

CDI Tech Support

Petty Officer 2nd Class
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May 14, 2010
Messages
127
Re: Help with 1976 mercury 1150. No fire

If ok, check voltage on brown terminal of pack(trigger side) as it must be a least 9.5 VDC.
Make sure this test is done at cranking.

If thats ok jump the brown & white together and turn key on, take a jumper wire and ground one end and tap the black trigger terninal and it should tire each time.
Make sure the trigger is completely disconnected before performing this test. What you are doing in this test is manually making the switch box spark.

See the illustration in our troubleshooting pages on this ignition here:

CDI Troubleshooting Guide

Shortcut:

Mercury 4 and 6 Cylinder - 332-2986
 
Joined
May 24, 2010
Messages
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Re: Help with 1976 mercury 1150. No fire

CDI Tech Support


Thanks for you schmatics and procedure for testing. This will come in handy for testing. Also i was on your web site and was looking for parts (ie switch box and coil just in case.) All i seen was the 114-2986 that it says replaces the 332-2986 switchbox. But I don't think mine has the A+number on it like shown in your list. If so it looks like it has the coil in with it. would this be a replacement switchbox for mine and eleminate the separate coil that i have.


Thanks Rick
 

CDI Tech Support

Petty Officer 2nd Class
Joined
May 14, 2010
Messages
127
Re: Help with 1976 mercury 1150. No fire

i was on your web site and was looking for parts (ie switch box and coil just in case.) All i seen was the 114-2986 that it says replaces the 332-2986 switchbox. But I don't think mine has the A+number on it like shown in your list.
"A" numbers from Mercury, more often than not, are tiny revisions to the same part. Our 114-2986 will replace any Mercury switch box that has "332-2986" in the part#.

If so it looks like it has the coil in with it. would this be a replacement switchbox for mine and eleminate the separate coil that i have.
Yes, our 114-2986 has its own ignition coil, thus eliminating the OEM ignition coil.
 

-JR-

Petty Officer 2nd Class
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Jun 21, 2009
Messages
133
Re: Help with 1976 mercury 1150. No fire

Been reading up on the the no spark .... might be a tilt switch.
Can someone explain .
Will eingine not give spark if tilt to high !
How does it look like ?
 
Joined
May 24, 2010
Messages
9
Re: Help with 1976 mercury 1150. No fire

Mercury tilt switch was not connected. So I was told that it didn't have to be that if unconnected it was just bypassed and didn't need it. Is this correct?

I did check the volts on the brown wire on trigger side of switchbox wire cranking. Battery was charged to 12v the brown wire on trigger side of switchbox while cranking was 6.6v. Does this mean my switchbox is no good and needs replaced? I appreciate all the help you all have been giving.
 
Joined
May 24, 2010
Messages
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Re: Help with 1976 mercury 1150. No fire

Ok latest saga. I tried 2 other used switchboxes that a Marine repair/salvage yard had in Oklahoma, which graceously allowed me to test before buying. Both gave me the same reading of 6.6 volts on the brown trigger wire which was what mine read. I am using a digital voltage meter to test. Is the the proper equipment to be testing. Is the likelyhood of all three giving the same reading mean that all three are bad or am i doing somthing wrong during the test. I have ordered a new coil to try and see if that is what is wrong. The records I got from the person I boat the boat from shows a used one (coil) was put on in 2006. It also had a new trigger from CDI put on at same time. I was even told by a marine motor repair person that it could possibly be the fuel, even though I explained I had no fire at the plugs (tested with a spark gap tester). Emptied and replace fuel/oil mix and added a can of seafoam, still no start and no fire. I am utterly stumped. Would like to save on cost if it is something I could replace before sending it to the shop. Any assistance would be greatly appreciated.
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
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15,931
Re: Help with 1976 mercury 1150. No fire

If you have tested it step by step from the CDI troubleshooting manual remove the coil wire from coil and install a spark tester from coil to a good ground and see if you have spark. If you do its in the wire,cap or carbon and also clip a grounding wire from a good ground to the trigger body and retest.
 
Joined
May 24, 2010
Messages
9
Re: Help with 1976 mercury 1150. No fire

Faztbullet. Ok I checked the fire to the coil wire. No Spark during cranking. I did get spark if I just bumped the key to start.

So I perfromed the following: I unhooked the trigger assembly from the switchbox and jumped the Brown and white terminal together. I ran a second wire from a ground. I unhooked the coil wire from the distributor cap and put a tester on the coil wire. I touched the grounded wire to the blacked terminal and it sparked every time I touched the black termial. Does this mean my Trigger is bad? I do appreciate all the help everyone has given.
 
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