1974 Merc 1150 power of tower no spark

I bought a 1974 Glastron CV-16 with the Merc 1150 and I'm assuming it's a 74 as well for $ 300.00 in the fall and thought I'de get it going this spring. I fogged it and drained the lower unit juice and all looked good. I went to start it for the first time this spring ,as I had to get a new shifter box and cables, after shooting some carb cleaner in the carbs it fired right up. tried to start it again a couple weeks later and I'm getting no spark at the plugs. Looks like some of the wires under the hood are in bad shape and am going to replace. The battery cables did touch when trying to start one time, am wondering if that had anything to do with it. In the early stages of diagnostic. Any help will be appreciated. I've gotten alot of good suggestion so far on the forum and am going to try them.

Re: 1974 Merc 1150 power of tower no spark

You may have damaged something with the battery cables. You need to go to CDIElectronics to get the ignition test sequence.

Re: 1974 Merc 1150 power of tower no spark

Make sure you have 12V available on the red terminal of the switch box.

Re: 1974 Merc 1150 power of tower no spark

Get the engine harness fixed up or replace it. Then you can work on the ign. That motor needs +12vDC on the red terminal of the switchbox at all time. The white terminal next to it needs power when you want the motor to run.

Re: 1974 Merc 1150 power of tower no spark

Thanks for the suggestion I'm waiting for the weather to warm up so I can get out in the garage and start in on replacing the uncoated green nasty wires, the coating is so brittle it just crumbles when I move the wires around. I'll keep everyone posted with the results. I should post some pictures of the boat for any Glastron fans.

Re: 1974 Merc 1150 power of tower no spark

Well I did replace some bad wires and the motor started. The reason I didn't have any spark is the 1 plug I was checking which is the 3rd down from the top had aluminum or metal melted around the plug diod and around the pug hole so after doing a compression check on all of the cylinders all were 120 to 125 and the 3rd one was 25. I'm freaking bumming big time. Any suggestions, I'm thinking a ring melted. I really don't want to tear this thing down. I appreciate all of the help ths far.

Re: 1974 Merc 1150 power of tower no spark

Oh ya can anybody verify the year of my motor, serial # 3942761? Thanks,

Re: 1974 Merc 1150 power of tower no spark

The maxrules.com website will have the year of the motor by serial number. Pull the middle transfer cover and inspect the #3 cylinder. I think you will find the rings are all scratched up as is the cylinder. If so, you need to tear it down and bore out the cylinder and install oversize piston and rings. If the scratches are light, you may get away with hone and new std rings.

Re: 1974 Merc 1150 power of tower no spark

Thanks Chris for the input, I'll have to figure out where the middle transfer cover is shouldn't be to difficult. If I have to rering that will the whole head have to come off. I'm somewhat mechanicaly inclined I've did motor swaps, head gasket on a v-8, piston and rings on my v-max hopefully I can figure this out as I don't want to put the cash out to have it done.