Mercury 9.8 Will not Get Up & Go

I purchased a 16' aluminum boat with 9.8 HP Mercury 2 stroke outboard (serial number A176839 - not sure what year).

I had to use some starting fluid to get it started at first but now it starts fine but will not seem to rev up to speed. It idles fine and goes maybe 5 mph but when I go from 1/2 gto full throttle there is no real change and it feels like it is struggling or running rough. Also - when I prime the pump balls on the gas line once they are primed it will squirt a little gas out one of the ports on the carb?? (I did install new plugs and am using new gas)

Please let me know if anyone has any idea's on what I should do to get this running correctly.

Re: Mercury 9.8 Will not Get Up & Go

have you cleaned the Carb, you may have a bit of trash hung in her.... did the boat sit for a while if so i would pull the carb and give her a good cleaning and maybe a rebuild kit... not much cost and a do it yourself project if you have a bit of smarts lol.... maybe it just needs some adjusting.... I just had a 25 hp merc do about the same thing that yours is doing, i could pump the bubble and gas would squirt out of the front of the carb ...cranked up easy but wouldnt run full throttle. i took the carb off.... took it apart real easy like and cleaned everything with some carb cleaner even put it back together with the same gaskets and she runs Great.... i would suggest a carb kit... IM NO MECHANIC I JUST FISH lol.. good luck...

oh yeah .. do you have spark on both plugs... maybe she is just kickin 1 and thats the problem have you check the spark ?

Re: Mercury 9.8 Will not Get Up & Go

Thanks for the note - I was heading towards the carb next. Any easy way to check spark on these outboards?

Bign71 said:

have you cleaned the Carb, you may have a bit of trash hung in her.... did the boat sit for a while if so i would pull the carb and give her a good cleaning and maybe a rebuild kit... not much cost and a do it yourself project if you have a bit of smarts lol.... maybe it just needs some adjusting.... I just had a 25 hp merc do about the same thing that yours is doing, i could pump the bubble and gas would squirt out of the front of the carb ...cranked up easy but wouldnt run full throttle. i took the carb off.... took it apart real easy like and cleaned everything with some carb cleaner even put it back together with the same gaskets and she runs Great.... i would suggest a carb kit... IM NO MECHANIC I JUST FISH lol.. good luck...

oh yeah .. do you have spark on both plugs... maybe she is just kickin 1 and thats the problem have you check the spark ?

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Re: Mercury 9.8 Will not Get Up & Go

heres what ya do partner... pull the plug ... put the plug wire back on it ... get your wife to hold on to the spark plug while you pull the rope.... if she screams and smacks the #@$% out of you... that one has spark, repeat same for other side. lol.... actually all of the above except use some insulated pliers to hold on to the plug and look for a spark while you pull the rope, you may need 2 people to do this.... thats how i checked it on my engine ..good luck

Re: Mercury 9.8 Will not Get Up & Go

You can also buy a cheap in line spark tester for $3 or so.

I'd also suspect carb trouble but it could be something simple. Had a 4 hp johnson that had identical symptyms . Turned out that the cable that advanced the spark ( by turning the plate under the flywheel) had popped off.

Re: Mercury 9.8 Will not Get Up & Go

Thanks for the laughs - wife would have held that plug years ago but she is a little smarter now. Will need to anee up for the tester. Thanks for all the help to everyone.