Mariner 5hp smokin bad/model year ?

[Pete E]

Hey just jioned this site. I just got my 5 hp Mariner going and it smokes like a heck. I'm running 50:1 and air screw is 3.5 turns out. Seems like alot to me. Atleast from my dirtbike stand point. The plug is black instead of the mocha color I like. Any idea's? The plug is a NGK B7HS. With that plug motor can run for a half hour and I can pick it up. It's only warm. I'm thinking I need to go to a hotter plug mabye. Also looking to find out what year it is. Serial #155122 ,Model 5M, code 6E3S. Any idea's.
Thanks Pete

 

[rickdb1boat]

Re: Mariner 5hp smoking bad/model year ?

Re: Mariner 5hp smoking bad/model year ?

Hi Pete,

5 M 6E3- 154262 -159029 1988 Model

B7HS gapped at .024 is the correct plug. I don't know if that motor has a thermostat or not, but if so, it could be stuck open and causing it to run too cold. Might check it out...

EDIT: Looks like it does have a T-stat from the diagrams...

 

[Pete E]

Re: Mariner 5hp smokin bad/model year ?

Thank you, thank you, thank you. Now I the year is a big help. Where did you find a diagram ? I would've never guessed it had a t-stat either.

 

[rickdb1boat]

Re: Mariner 5hp smokin bad/model year ?

http://www.mercruiserparts.com/mercruiser_parts.asp ] Click Here [/url]

 

[Texasmark]

Re: Mariner 5hp smokin bad/model year ?

Most engines of today have fixed high speed jets and still have adjustable low speed jets.

The normal setting for a low speed jet, that hasn't been ruined by turning in too far and bottoming out, is 1 1/4 turns CCW open for starters and if too lean, a quarter or two more opening.

Start with that and lets go from there.

Mark

 

[Pete E]

Re: Mariner 5hp smokin bad/model year ?

Someone on another site asked if I was running it in a barrel which I was and he said that they tend to smoke alot. He also told me to tune it on the boat which I'm going to do tomorrow. I turned the air screw back in some but will start at 1 1/4.

 

[Pete E]

Re: Mariner 5hp smokin bad/model year ?

1 1/4 out did it8). What a difference running it on the boat made. The plug is a light charcoal color and I'm sticking with it. Didn't smoke like it did in the barrel either. My nexted problem is with me and family in boat and throttle wide open it seemed like it was boggin down. I should think a 5 horse should move a 12 ft aluminum boat along at a good pace. Any idea's ??
Pete