Hard to start 115 mercury outboard

[juiceisu]

I have a 115 horse mercury outboard with 6 plugs. I have always had trouble starting the motor. I usually have to push the throttle forward to get it to start. I just changed the spark plugs recently and the last time I took the boat out I had trouble with the motor. It stared chugging and vibrating the entire boat. It seemed like it was missing a little bit, but really couldn't tell.<br /><br />Any tips?<br /><br />Thanks<br />Justin

 

[jeep]

Re: Hard to start 115 mercury outboard

I would suggest checking for spark at the plugs when running. Perhaps they are not getting a good spark going. <br /><br />Another option might be the fuel/carbs. Check that fuel is getting to them. I was told to put some fuel mix in a squirt bottle and spray each carb to see if it helped the running. <br /><br />good luck

 

[aeronutt29]

Re: Hard to start 115 mercury outboard

You didn't provide much detail about your motor, but I suspect that you have a carburetion problem. Take the carbs off and clean them out thoroughly. Disassembling and soaking them overnight in carburetor cleaning solvent works best. They will come out looking like brand new carbs. Probably work better too. DO NOT RUN PLASTIC OR RUBBER PARTS THROUGH THE SOLVENT!!! Gumout aerosol probably won't hurt the plastic parts, but the super corrosive soaking bucket stuff will dissolve them completely. Most motor machine shops have a bucket of solvent that they will soak your stuff in for a small fee. This is probably the last time you will need to do it for years, so there's really no point in buying your own bucket of solvent.<br /><br />Other things to look for include loose/old/damaged spark plug wires, corrosion in the distributor cap, clogged fuel filter, mis-adjusted choke linkages, and poor wire connections. One thing that I found on my motor was the previous owner didn't figure out that the coil wire SCREWS into the center post of the distributor. He pulled hard enough to get it out anyway, then just mashed the wire back up into the hole. If you have already broken the wire from similar rough handling, go buy a new one.

 

[mbb]

Re: Hard to start 115 mercury outboard

all those old motors are difficult to crank cold, they must turnover fast, and dont choke well. Bottom carb doesnt choke at all.<br /><br />Important thing is dont run it if it doesnt seem right. No quicker way to ruin it.