Just picked up merc 115 been sitting for years

[badbowtie]

I just picked up a 1974 starcraft with the original 115 outboard on it boat is from original owner and always been garage kept. About 14 years ago raccons got in and destroyed the interior and has been sitting since then. I would like to see what you guys recommend to try to at least get it to run before I start spending money on rebuilding the carbs and all that. I did pick up a can of stabill fog so I can spray it in cylnders thru plug holes and thru carbs. Or should I spray fog thru carbs and spray engine oil in plug holes. Looking for tips and tricks that you guys have had work. I would say as long as it cranks and has good compression then safe to say motor would be okay right.

 

[GA_Boater]

Cranks and has good compression says it cranks and has good compression. Fuel and spark are the rest of the equation.

I would squirt a little TCW3 in the plug holes and spin the motor a few times by hand with the flywheel with the plugs still out.

Check the spark and if good, squirt some pre-mix in the plug holes, put the plugs in and crank her over. If it spits or pops, hook up a tank of fresh pre-mix and give it a shot. Put muffs on first in case she takes off.

 

[Chris1956]

I am with GA-boater to a point. Squirt some TCW-III 2 cycle oil into the cylinders (spark plugs out) and turn her over by hand. If she spins smooth, with some resistance due to crankcase compression, it is time for a compression test.

Jumper the starter from a battery using jumper cables directly to the starter. If she spins, check the compression. All cylinders should be even or within 15% or so. If that passes, the motor MIGHT be worth saving.

I say Might, because the ign components are very expensive, and the raccoons may have damaged them. I expect the raccoons have damaged the wiring, or it just fell apart which is usual for a motor that old. That motor will have battery-powered CDI ignition with a distributor. The wiring needs to be in good shape for the motor to have spark.

Replacement parts, if they can be found, are aproximately: Dist cap $100; rotor $220; Plug Wires $6ea; Switch Box $250; Trigger $220; Stator $150.

 

[badbowtie]

Well I sprayed some tcw3 in all the plug holes first thing this morning then did several other things to boat and with plugs still out grabbed flywheel and turned nice and easy. So I put plugs back in and unhooked fuel hose and hooked it up to a smaller 6 gallon boat tank with some fresh fuel and it fired right up. Sat and ran great no problems and starts right up. Here is a video. Thanks

 

[racerone]

Now is the time to intall a new waterpump impeller.-----Yes this MUST be done.

 

[badbowtie]

Yea I will install one before spring for sure time to start setting up interior and got the rest of the winter before fishing season starts.

 

[mr 88]

NAPA has the spark plugs if need be. The plug wires are screwed into the distributor and boots ,just so your aware of this.Run some sea foam with your gas and maybe you wont have to touch the carbs,the engine sounds good. These motors loved to be primed when cold,something you will notice more when your trying to start it in the water,more back pressure so she doesn't spin as fast. I ended up putting a 3/8 ID one way check valve between the bulb and the engine to eliminate the bulb from having to stop the back flow,they seem to seep. Then I over prime the bulb,forcing some fuel into the system,this helps the cold water starts. Once she fires up your good for the day as far priming goes and she usually starts at the first click of the key.

 

[badbowtie]

Yea I have a can of sea foam for the new tank of fuel once I get the tank cleaned out and installed. I also assure it is 50:1 correct? The only other thing I noticed while it was running the tach doesn't work so not sure what up there yet.