no fire on '75-'76 Mercury 1150

[cat fisher]

I have 75 or 76 Mercury 1150 that is not getting power to the coil. There is current coming from the switch box to the trigger in the distributor, but when I turn the engine over there is no power coming back from the trigger. I am testing with a 6-12V test light. Is this an adequate test, does it sound like I need to replace the distributor, or could there be a problem with the switch box? Thanks!!

 

[12Footer]

Re: no fire on '75-'76 Mercury 1150

While you have the distributor cap off, take the rotor in hand and see if it turns free.<br />If it does, this is your problem. Also,this motor has a timing belt (a little one) going from the crankshaft under the flywheel, over to the top of the distributor assembly.<br />If you find a source for that rotor/shaft assy, PLEASE let me know. I got one that has done the same thing.<br />From what I am told, the shaft and rotor do not seperate!<br />Ay, carumba!

 

[12Footer]

Re: no fire on '75-'76 Mercury 1150

Also, see a post from me dated July 30,2001,entitled "74Merc Rotor". It should be a few pages back (busy little board, aint it?).<br />It's not looking too good from the money side of things

 

[kevlar3000]

Re: no fire on '75-'76 Mercury 1150

Hey 12,<br /><br />I have seen some good prices on ebay. There is a place called Twin City Outboard in Channhassen Minnesota that would have one complete, used but complete, might be worth it to see if you can find the # on the yahoo yellow pages.<br /><br />Good Luck!!

 

[cat fisher]

Re: no fire on '75-'76 Mercury 1150

Thanks for the info; The rotor is solid on the shaft and the shaft only turns with the flywheel (unless the belt is removed)<br /><br />I think what I need is a way to test the trigger mechanism in the distributor, so I can either rule it out or decide it is the problem. I am convinced it's either the trigger or the switch box.<br /><br />I have found a few outboard salvage yards I will post them shortly

 

[12Footer]

Re: no fire on '75-'76 Mercury 1150

Good news for me, at least.. I found one locally for 10bucks. The only catch is, I pull it myself. So Saturday 8AM, I'm heading out with my tools.<br />But thanks, Kevlar. I was begining to panic when I was qouted $120 for it and a USED timing belt!<br />Cat, I would suspect the switchbox too on yours. Does your model have the paired type switch boxes?

 

[cat fisher]

Re: no fire on '75-'76 Mercury 1150

Congratulations on finding your part. I'm listing some used part sites I've found below.<br /><br />My Merc has one switchbox that mounts in front of the carbs. Does anybody know how to test the trigger signal on the distributor, it is officially a pain in my a##.<br /><br />Some boat salvage site are: www.charliesusedparts.com www.outboardrecycle.com www.outboardsalvage.com www.woodardnarine.com

 

[12Footer]

Re: no fire on '75-'76 Mercury 1150

The book claims you need an anylizer to check the trigger and switchbox on these engines. This is true for the most part, but...<br />There are three wires comming out of the distributor, that send the pulses to the switchbox. Draw a road map, then disconnect<br />them at the switchbox.the point where they attach to the distributer housing contains two coils.<br />Since they are coils, you should have continuity across each coil. However, they<br />dont carry anything but a minute signal current during operation,so chances either coil has failed are extremely thin.<br />Everthing else (SCR-trigger signal,Field charging/discharging) are handled by the switchbox into the one coil (which you mentioned wasn't getting the pulse). <br />Before going any deeper, have you checked the ignition switch by disconnecting the orange wire on the male end of the harness plug?<br />I dont know what color this wire is on the engine, but you can trace it out. Make sure this orange wire is not shorted to ground,because this is how the engine is shut off at the key.. In other words, the ignition key grounds this orange wire to kill the motor.

 

[firediver3]

Re: no fire on '75-'76 Mercury 1150

I have a 77 1150 that would work for a while then no spark, the problem got continuously worse. After some checking I found out you do have to have the trigger tester to check the trigger, but all signs pointed to there. It is a pretty pricey part, it is only avalible as a assembly(distributor housing) but after changing the trigger the motor is up and running like a champ again. Good luck.

 

[12Footer]

Re: no fire on '75-'76 Mercury 1150

Firediver, What part failed in the assembly,do you know?<br />And you are right about the pricey!!!! You would think the engineers woulda made it more "take apart-able". My son is an electrical engineer, and i send him photos of brain-dead designs like this.He gets a kick outta them.

 

[firediver3]

Re: no fire on '75-'76 Mercury 1150

Sorry for so long to post. It was the trigger I couldn't find just the trigger, I had to buy the assembly. I think that one reason for it being pricey is there was no core to return. It seems like a lot of machining to make a new distributor assembly just to put a new trigger in there. After I got the part it only took a couple of hours to get it back together and on the boat. Just make sure that you get the timing right the first time if it is to far off you have to almost totally disassemble it again

Good luck and I hope that you find one cheaper than I did, about $338