1972 MERCURY 115 hard starting cold

[Matt O]

Hi guys and gals, I just found this forum and I think I can read for days. I am fairly new to boating, and I just recently purchased a 1976 Hydro-sport that has a 1972 Mercury I6 with Thunderbolt ignition, distributer type serial number 3271699. This engine has great compression 130 on all cylinders warm and cold. The problem I have with it is cold starting. This thing is nearly impossible to start cold. I have checked the chokes on the two lower carbs and even tightened the screws that hold the cover on so they seal better. I have checked spark when it wont start and it has spark. I have to play with the choke and the high idle/ignition advance lever and takes a while and than it starts. Warm restarts are generally less than 1 second of cranking. If it sits a few hours it will start fairly Ok but if I leave it over night or through the week its a bear to start. My question is, is this common, what effect does the lever have on actually starting it seems like at times the engine won't crank unless I wiggle the lever, does this incorporate the neutral swtich in this and are these common failures that ca cause voltage problems and make em hard to start. I am sorry if I am rambling but like I said I fix cars for a living and these are new to me. Any advice on what to do? I have changed the plugs, it had Split fires in it, the cap, coil and wires look OK, and the owner I bought it from said he had the carbs redone. He said that if you hit it with some carb cleaner it fires off, I realize that thats not good as the fuel lubricates the engine as well. So I won't do it. I may have burned the starter up this AM getting it going, so I am scared to take it out on the water, I haven't had it there yet, but want to next weekend. Any and all advice welcomed. <br /><br />Matt

 

[ZmOz]

Re: 1972 MERCURY 115 hard starting cold

Most of the old ones are a little difficult to start cold. I have an inline 6, 150hp, and when I first got it I had a hell of a time starting it cold. Make sure you have the engine either level or "tucked in" a little bit. Then prime it until you see gas running from the carbs. (keep pusing on the primer even after it gets hard) Then put the neutral idle all the way up, hold down the choke, and start. Should fire right up. If you have it connected to a hose, make sure to put the neutral idle lever back really quickly, all the way up is waaaay to fast out of the water. If it still is hard to start you probably aren't getting enough juice to the starter. Could be the battery needs charging or replacing, could be loose or dirty connections, or you could need new battery cables if they aren't in the best condition. Also it does have a neutral start switch, if it's not engaged it won't crank at all.

 

[Gold Bear]

Re: 1972 MERCURY 115 hard starting cold

drive camp <br /><br />It also helps to tilt the engine all the way down.<br /><br />My 1972, 115 is also hard to start. I made a primer system with three squirt nozzles, 1/4" hose, primer bulb and a 1 gallon plastic tank (cost about $10). Now my engine starts great.<br /><br />You can also use a premix / squirt bottle, but then you have to pull the cover off.<br /><br />Good Luck,<br /><br />Gold Bear

 

[Matt O]

Re: 1972 MERCURY 115 hard starting cold

Thanks for the replies and the suggestions. I think I am going to get me an old oil squiter and try priming th carbs if that works I will make a permanent primer system. Does anyone know if starter bushings and brushes are available anywhere. Local Mercury shop says NO longer available. Thanks again,<br /><br />Matt aka drive camp

 

[ZmOz]

Re: 1972 MERCURY 115 hard starting cold

That's a good idea, Gold bear. What did you use for the squirt nozzles? And did you just use a regular outboard primer?

 

[Gold Bear]

Re: 1972 MERCURY 115 hard starting cold

ZmOz <br /><br />I used a short piece of copper tube approx 3" long. At the end of each tube I soldered it closed, then drilled a small hole through it. (use a small file to rough up the inside of the tubing - to make sure the solder never comes out!)You can use the copper to bend the last corner so you can route the direction of spray into the carbs. Fit the copper tube through the mesh of the plastic "grids" over the carbs, through a location that wont interfere with the operation of the choke blades. The copper tube sliped nicely into the 1/4" hose I used. I went to Wal-Mart and bought a 1/4" primer bulb. I used clear plastic hose so I could see the fuel flowing. As it works, you can hear a squish sound when the fuel sprays out the nozzles. About two or three good pumps on the bulb, and she starts right up. I do not even use the fast idle lever any more.<br /><br />Regards,<br /><br />Gold Bear

 

[Matt O]

Re: 1972 MERCURY 115 hard starting cold

OK I tried it a few days, here is how I got it starting great cold. First I did run the Sea Foam deep creep through it adjusted the idle mixture screws richer for a dying when going into gear, but that didn't help the cold start. What did? Just what was suggested, I went and bought me a little oiler like was used back in the day, I put 50:1 mix in it, I take the cover off open the throttle, pump 3 small squirts into each carb, close the throttle, pop the cover back on and turn the key. Thats it, no choke no high idle nothing, just fires off. Thanks alot guys I will be making a primer like suggested this winter, but for now, my little oiler will do just fine. Thanks alot. And Happy boating.<br /><br />Matt