'81 Mercury 50HP Questions...

[pyro225]

Hi all - i'm sure most of you have seen my posts...

Basically quick lowdown...

I got a new to me merc 50 '81 outboard that ran but needed the gearbox oil and impeller doing...but the problem was the box wouldn't come off...

Anyway so got the box off, new impeller, pump housing and oil...

So i then got it together at the weekend, started it 3rd pull, not bad for not running for 9 months... i then left it running for 5 mins no problem... it was on muffs so not too high revs...

Ok so come today, we dropped the boat in the water, it was a 10 mile driver from where the boat was... got the boat in the water went to pull start it, must have tried 30 times, no joy, in the end had to use a little easy start and still another 10 pulls until it fired... i then had to do another 5 pulls before running...

So my question? why was it that hard to start? when running it ran fairly well? any ideas?

also when idling at tick over it seems to stall after about 30 seconds - bump up the rpm 500 and it seemed fine... ideas?

flat out with a 14p prop on i was hitting 28mph on a Glastron ssv151 is this about right?

finally when i was flat out about once a minute i could here a ting kind of light metal on metal sound from the outboard... any ideas?

thanks in advance...

 

[Texasmark]

Might be a pre ignition ping on the tick caused by carbon fouling. On the starting problem after running and sitting for 9 mos, you probably dislodged some crud in the carb(s) and it clogged up your venturi supply port in the carb. Berryman's Chem Tool (WM has it) and compressed air and new carb kit is what I would suggest.

Then new fuel, with some Sea Foam to clean up the cylinders....directions on can but first 6 gallons I'd dump a whole 16 oz can in it......it doesn't affect your oil gas ratio so continue to put one pt. of oil to 6 gallons of gas (50:1).

Mark

 

[pyro225]

Cheers Mark, sorry as you mentioned it i forgot to, i gave the carbs a full service prior to putting them back in - looked like new? any ideas? anything on the idle - and the metallic sound at full throttle? thanks again!

 

[pyro225]

also is it with doing sea foam still iv ran with new fuel for about 3 miles

 

[Texasmark]

Don't understand your last post but I think you said you have run new fuel for 3 miles didn't understand the rest. So assuming that you were asking about the sea foam anyway, my answer is yes do it anyway. I came to this site about 10 years ago where I heard about the product, never heard of it before. The big guns on here raved about it. I used it on several 2 stroke engines of different functions over the years and loved what it did. I had a chain saw and weed eater (string trimmer) that I thought were dead and revived them. Was amazed. Have used it ever since.

So yes dump a whole can in a tank of gas and run it and then keep it in your fuel at the can recommended rate of 1 oz per gallon. I never had a carb problem with the engine I have had since joining and never did a carb kit on the engine until it was 10 years old. Even at that long period, the interior of the carbs and the piston crowns were spotless.

If you had a constant ticking then you might worry about it. But to me, being intermittent, not anything serious especially on that engine.

HTH,
Mark

 

[pyro225]

Ok brilliant can I use the boat at full speed after dumping a whole can in?

 

[Texasmark]

Why not? I am assuming that your cooling system is operating properly since you have been into the water pump. Tell you what, just to be sure, remove the cowl so that you can put your hand on the top rear of the engine block. Take her out and run it at WOT for several minutes and shut it down. The block should be warm to the touch such that you can hold your hand on it without having to remove it. If so, fine go for it. If it's hot, water pump needs servicing again or something else in the cooling loop is not functioning.

Mark

 

[pyro225]

Ok i will have a go but easier said than done as i have a pull start and choke in the cowling.