Mercury 1150 Maintenance Questions

[TNRoostertail]

Hey all, just picked up one of these old engines and want to get it back into fighting shape. It's a 1976 115 hp Thunderbolt. I don't want to add power or look for tricks to add power or anything like that. I just want it running good.
It runs good right now but it slow to start and the water pump needs changed as the stream is weak. I want to ask you all about the items needed and possible a good spot to get them.
I want to change the lower gear oil, what oil do you all recomend?
I want to rebuild the carbs and clean them up, what kit do I need?
I also want to do the water pump and any seals involved with the lower end, what do I need here?
And is there any electronics on the ignition I should replace?
And sites where I could get everything in one go would be great.
I have already purchased the 3 lead vacuum gauge to set vacuum on all three carbs, anything else I need?
Thanks in advance and I'm happy to be apart of this forum!

 

[Faztbullet]

Well you can get all the parts/rebuild/reseal kits you need here on iBoats. Use a NON automotive 80w/90w gear oil for lower unit.The ignition wiring needs inspected as it has tendency to rotten from inside out. Never disconnect battery when running as it can damage trigger.You don't need gauges to set up carbs that's for 4 stroke...

 

[Chris1956]

To add to Fazt's recommendations:

Remove carb covers as an assembly. Remove cowling support and starter (D/C battery first). Top carb is a bit tricky to remove, but will come off, with some wiggling. clean the carbs and replace all gaskets, inlet needle and seat and floats. Some motors have copper gaskets under the inlet needles. Set float height correctly. Carb idle mixture needs to be slightly richer to allow acceleration. That is to say, if you adjust carbs for best idle, she will likely stumble upon acceleration.

Inspect spark plugs wires for arcing to ground. If you remove distributor cap, remember that rotor is not removable and is fragile. It is $200+ to replace and a PIA to install. Wipe cap clean and inspect carbon electrode. Replace if it is worn.

Replace waterpump impeller, wearplate and 2 gaskets. Inspect waterpump cover for wear and scratches. Replace if you find some. Any Marine Gear oil for mechanical shift motors is fine. Wallyworld usually has some.

Use fresh fuel, mixed at 50::1 with a TCW-III 2 cycle oil.

Don't alter set screw settings on plate above distributor, and you should not need to re synch motor.

Enjoy..

 

[1960 Starflite]

The engines of the 70's have bad wire insulation. You may find that the wires are in really bad shape. My, new to me, 1975 "850", was in bad shape as the wires go. CDI has wire kits. I took my time and replaced all the wires with automotive wire. If you have to solder some wires, use flux or it wont take. Spark plug wires need to be stranded, not carbon based. The spark plug wires screw into the cap, don't pull them out.

In fact, you may not even have a distributor. I'm no expert. Mercury changed some engines over during the 70's.

 

[TNRoostertail]

Thanks for the recommendations guys. That was a big help. I will stop by wally world and pick some gear oil up. I had some redline mt90 left over but its auto grade. I will also inspect all wiring and probably just replace it. Thanks for the advice on the distributor cap and rotor. I might have tore the rotary button up if you hadn't advised me on it. Well time to dig in, thx again all. When I get it running right I will start a thread on my prop.

 

[TNRoostertail]

Would you all know the correct water pumo kit for this engine? Thx

 

[TNRoostertail]

Ok guys found the right water pump kit. Bought the the complete kit with new housing. All I need is the correct carb kit for the motor and im good to go.

 

[Chris1956]

The carb kits are pretty generic. They are made by GLM, Sierra Mallory and OEM. Make sure you get all gaskets, floats and inlet needles and seats. It should be about $50.