Merc 9.8hp year 1980-81

neerajsus

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Jun 15, 2017
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Hey guys! I have a merc 9.8 hp serial # 5639882. Has a tillotson carburetor with a built in fuel filter attached on side. The carburetor has 1364-7397 stamped on it. The fuel filter body has 1364-4928 and 1364-4929 stamped on it. The carb started gushing out fuel from intake whenever I hit the primer bulb. Also if somehiw it starts before dying after 20 seconds or 10 seconds or a minute, it starts on very high race....as in at the throttle revved up (no I don't do it it starts like that). I changed the impeller few days back since there was no pee comin out....but now it dies pee..except..its coming very hot...and I believe thats cuz the motor starts in high rpm's. Its very hard to find parts for this motor...atleast for me. Googled the net upaide down and can order carb kit, fuel filter kit with diaphragm, seat/needle and float. I was trying to find this carburetor if somebody has it but ebay has the later yrs as in from 1999 or so..as in the body assembly. How do we take the seat out of it cyz it seems like its just embedded in the body of carb. All input (constructive) welcome.
Thnx!
 

flyingscott

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Apr 8, 2014
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8,291
The seat is probably permanent because they have a needle with a soft tip. The carb kit i found only comes with the needle no seat. The last year they made your motor was 1985 so carbs any newer than that are for the 9.9 hp a different motor. Check the throttle linkage to make sure it is closing the carb all the way.
 

mercurymark

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May 31, 2003
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21
In my experience, it sounds like the the float needle is stuck open. That would account for the gas squirting out.
 

neerajsus

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Jun 15, 2017
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Mercurymark..yes the float was not only stuck hard but it was an old foam.style plastic coated float...plastic shell was cracked and the foam had been absorbing gas for who knows how long...i recently got the motor. But I did ordered the correct part number of float and now they make it all plastic moulded one piece. I put it in, put the carb back in the motor...primed the bulb and I could hear the gush sound....i took the head off and coud see fuel squrting out from intake valve.

I tried blowing in the tube which is attached to the motor (and the other end goes to the fuel filter which is built in and on the side of carb), it seems like the air won't go anywhere...I tried suction as in siphon out with a lil pump, some fuel came out from the tube. Is it one way only? Not sure if I'm making sense...but its the tube which goes from carb to the motor and NOT from fuel supply to carb.
The first pic is the brass nozzle on the carb from where this tube or hose i'm talkin bout goes and rhe second pic is that hose or tube goin to the bottom of motor and it goes over same kinda brass nozzle which is attached to motor....third pic is to give an idea what the motor in general on that side for above said refrences
 
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neerajsus

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Jun 15, 2017
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Its not letting me attach the pics....dayibg i'm not authorised to attach or remove attachments...how am i suppose to show pics
 

mercurymark

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May 31, 2003
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21
I think that little black hose you're talking about is a drain for any extra gas that?s left in the crankcase. It still sounds like your float needle is stuck open. When the fuel bowl on the carb is full you won't be able to pump the primer bulb. It will be hard.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Its not letting me attach the pics....dayibg i'm not authorised to attach or remove attachments...how am i suppose to show pics

in the rules you read and agreed to, you need to have a minimum of 3 posts under your belt prior to being able to attach pics. however in the rules and guidelines forum, there is also a tutorial on uploading pics using 3rd party photo storing sites like photobucket
 

neerajsus

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Jun 15, 2017
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in the rules you read and agreed to, you need to have a minimum of 3 posts under your belt prior to being able to attach pics. however in the rules and guidelines forum, there is also a tutorial on uploading pics using 3rd party photo storing sites like photobucket


Gotcha...I guess lil too impatient....
 

neerajsus

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Jun 15, 2017
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I think that little black hose you're talking about is a drain for any extra gas that’s left in the crankcase. It still sounds like your float needle is stuck open. When the fuel bowl on the carb is full you won't be able to pump the primer bulb. It will be hard.

Yes you are correct. However the fuel start gushibg out through the intake valve in just 2 or 3 pumps to primer ball....I've taken the whole carb apart this time and will clean it by dipping in berryman's chem dip...soak it for 24 hours.....and put new gaskets, seals, diaphragm (diaphragm doesn't look beat up...but some gaskets and seals were meshed into the body of carb...
I'm nit much of motor guy but in my prime use to have several motorcycles 2 strokes 100 cc and I did all carb cleaning and idle adjustments to get rhe swret humm of the engine ☺ but donno boat motors that well.....can you explain lil bit more about this drain pipe (mine is a like 3 inch pipe or hose or tube....goes from carb to the bottom of the motor where it slides over a nozzle built in the motor. I'll appreciate it ☺
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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your needle and seat are not working if you can pump fuel past it.....period

you have to run a wire thru the passages to make sure they are clean. simply soaking and re-assembling isnt cleaning the carb

the crank case vent is the line your referring to
 

neerajsus

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Jun 15, 2017
Messages
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your needle and seat are not working if you can pump fuel past it.....period

you have to run a wire thru the passages to make sure they are clean. simply soaking and re-assembling isnt cleaning the carb

the crank case vent is the line your referring to

So this crank case vent us one way only..like fuel cones out but won't go back...cuz when i tried blowing air it seemed it won't go....
 

neerajsus

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Jun 15, 2017
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Also..besides running a fine wire straight through tbe seat, there's no way to clean it since it doesn't come out of the carb body..
 
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