# Mercury 9.8 Spark Plug gap and other questions



## Honky Tonkin (Apr 4, 2011)

I bought new plugs for the motor and they come gapped at .040. The guy at the store says that I will need to adjust that gap for my motor. Does anyone know what the gap should be on a NGK (3626) B9HS-10 sparkplug for my 1984 Mercury 9.8 outboard?

Also have a QuickSilver 6 gallon gas can with a fuel gauge and it seems to build up pressure and force fuel into the carb when not running. It seems to seep out into the motor comparment a little. It also seems to force fuel out of the valve when I have the line disconnected. The only way i can get it to not leak too much it to leave the valve open on top of the cap. Should I just get anew can? Would it normally leak in the compartment with pressure?

Last question, the motor starts fine every time, but doesn't seem to be running as fast as it should when wide open. When it first takes it runs strong, but the motor seems to slow after a few minutes. it will also die if I "gun it" to fast, but if I slowly throttle it up it is fine. Any ideas for a resolution to this? 

I am not a motor person by any means, just don't have the money for someone to look at it, so I gotta figure it out myself.

Thanks!

-Joe


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## crazymanme2 (Apr 4, 2011)

Looks like .040.

https://www.dixiemarinesales.com/Spark_plug_Reference_Mercury.aspx


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## Honky Tonkin (Apr 4, 2011)

Well, thanks a bunch! I guess that guy just wanted to get the 2 bucks i paid for the gap tool out of me. I will be running it tonight and seeing how it does.


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## Honky Tonkin (Apr 4, 2011)

Well the motor seem sto run smoother, but a new issue has come up. The Carb seems to be getting to much fuel, and it is very wet. When it is running it seems to be dripping fuel and it then dies out. I couldnt' get it to run consistently without unplugging the fuel line and starting it few times. Once I got it running it would then run until it was out of gas. Is there any way a carb would be getting too much gas? Don't punch me if that is a dumb question. 

What are some basic carb troubleshooting tips?

Thanks!


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## crazymanme2 (Apr 4, 2011)

Could be a couple of things,but easiest would be take the carb off & give it a rebuild or just clean it.(sounds like floats stuck)
Unless I miss it when was the last time this motor ran good?


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## Honky Tonkin (Apr 4, 2011)

It hasn't ran great since I have had it, but it has ran consistently. I have only had it on the lake twice, this past weekend and the weekend before that. It seemed to run weak, but ran none the less.


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## crazymanme2 (Apr 4, 2011)

If you plan on keeping the motor I'd put a fuel pump kit in also.

When was the last time the impeller was changed?


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## Honky Tonkin (Apr 5, 2011)

I actually can't find any fuel pump kit online for this motor. Would you know the model number?


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## Honky Tonkin (Apr 5, 2011)

Took the carb off, cleaned it. Took the fuel pump apart nd cleaned it a lot! Found the float was stuck down in the bowl, so I moved it upward. It may be mis shaped, because it hits the bowl on the far side. I am not sure if that is supposed to be the case, but I put everything back together and it ran better than it has since i have owned it!!!! It starts first pull everytime , and to top it off there was a glog of hardened grease that was limiting the throttle. I removed it and the thing sounds twice as fast!!! I will find out this weekend.

I am going to try and find a new float to install since it is so easy to work on these things.

Thanks for the help!!


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