Old Merc starting problems

[fishnfoollures.com]

I have an old Mercury Mark 58AE 45 h.p. It can't seem to get enough gas to the carbs to start it when cold.<br />No matter how many times I pump the bulb and pull the choke it wont start when cold. If I pull the face plate and squirt a little gas in the carbs it fires right up. Once it starts it runs great and restarts easy till it cools off. What can I do to get more gas to the carbs?<br />Tnx FNF

 

[WillyBWright]

Re: Old Merc starting problems

Welcome to iboats.<br /><br />Unless there's a carb or choke problem, I'd say it needs reed blocks. There are grooves in the inner circumfrence where they surround the crankshaft. The grooves retain leftover oil-rich unburned fuel as a kind of seal. On multi-cylinder 2-strokes, each cylinder needs it's own partitioned crankcase chamber. To accomplish this the shared crankshaft has to have seals between each cylinder. The residual oil serves that purpose on Merc inlines. As the motor gets more and more hours on it, the grooves erode and wear and the ability to retain that oil diminishes. Your grooves probably aren't retaining enough oil anymore. Lack of that sealing is allowing neighboring cylinders to exchange the air inside and not suck the reeds open to draw fuel from the carbs (it's not breathing, it's hyperventilating). Once the motor is up and running, the grooves fill and seal-up again.<br /><br />Short of an overhaul, you might be stuck with the gas shot into the carb trick. Something that might work better would be a primer system incorporated into the old motor. It would take some considerable modification and fabrication, but it would be more convenient and alot safer. A primer physically shoots the fuel where a choke relies on draw to work. You can eliminate the choke and use the same button to actuate the primer. A Johnnyrude primer would serve rather well I would think.

 

[Laddies]

Re: Old Merc starting problems

The engine is simple to lean on idle, it could be a lean idle setting, chokes not working properly, dirty carbs (low speed circuit), the float level to low. Don't over complcate the problem--Bob

 

[Clams Canino]

Re: Old Merc starting problems

Yes,<br /><br />Don't take this wrong Willy, but I get "disturbed" when people jump to the worst possible problem FIRST, it scares people. (yes, I know you said carb/choke in the same breath)<br /><br />Sure, the reed blocks are known to wear over time, but that's like a last resort cause of the problem as it involves a complete teardown.<br /><br />USUALLY, if it'll idle good under normal running conditions - the reeds aren't the 1st place to go.<br /><br />-W (I also own a Mark 58AE, Factory Burgandy - what color is yours?)<br /><br />PS: Decarb that thing at least once a year.

 

[fishnfoollures.com]

Re: Old Merc starting problems

Great news guys.<br /> As it turned out the main problem with my motor was the starter. It was shorting out and not spinning the motor over fast enough for it to start good, as well as using up all the juice for the spark. I put on a new starter and turned the idle screws out a 1/4 turn to 1 3/4 turns out and now it fires right up even in 30 deg weather. <br /> Clam, mine was the ugly cloud white but when I rebuilt my boat, I shot it in Jet black. It looks 100 times better. Now that it's running good I can't wait to get in out on the water and get me a bass or 2 this week. I hope.

 

[WillyBWright]

Re: Old Merc starting problems

So much for my assumption that you checked out the obvious first. I forget that not all people are familiar with the idiosyncracies that give Merc Classics their charm. Sorry about that. Mine was a white one that was painted black too (sand off all the oxidation or the paint will flake off, trust me!). Rope start model. Routinely started first pull after the overhaul. (Actually it wasn't mine. It was a marina toy. Boat and motor had little resale value, but it floated and ran great.)