9.8 hp merc carb cleaning/ tuning

[TKnittel]

Ok so.. have a 9.8 hp mercury outboard.. no idea what year... but its old.. and im sure were not getting enough power out of this motor.. it seems to skip occasionally while running, almost like it misses ... should we clean out the carbs?.. if so.. how do i do this.. and how/what would be the best way to "tune" this motor to pur like a tiger?...Thanks !!!

 

[jerryjerry05]

Re: 9.8 hp merc carb cleaning/ tuning

On the motor someplace is a sticker/tag with a mod# and serial# always include these.That way we can figure out the year and get the right parts and repair manual.
Done a compression/spark check??While your at it rebuild the fuel pump andreplace all the hoses. Ethanol is not our friend.
The miss at low speed could be the air screw needs adjusting.The miss at higher speed could be water in the fuel.
Cleaninmg the carb.Take a couple of pics before disasembly.Then removed the carb and take it apart. The front/side has a screw that controls the air/fuel mixture.Remember the setting for that screw.Turn it in(gently) till it just stops(gently).Remember the setting.
Use any off shelf cleaner.Then use tip/orafice cleaners on the jets.
Reassemble and put the air screw back where it was.
Final tuning is done in the water.Engine warm and in gear.
Turn the air screw in till it makes the motor cough/buck/stutter.Then out 1/2 turn
RPM's 750-800 in gear. Good luck,Jerry

 

[pikefisherman]

Re: 9.8 hp merc carb cleaning/ tuning

I have the same motor I think . I am not able to give you pro. advice like some of the others but can tell you that their dosent seem to be much to this carb. I'm looking to get a kit for mine today.You cant get some parts any more.

 

[jerryjerry05]

Re: 9.8 hp merc carb cleaning/ tuning

Most times the parts in the carb can be reused.Ethanol is not a frien.Replace all the hoses and any inline connectors.J

 

[TKnittel]

Re: 9.8 hp merc carb cleaning/ tuning

Sounds good.... Ok the serial number is A111853... And is model 110.. I believe it's a1985.... The impeller was replaced yesterday...and the water lines for the water pump seem clear... The tail tell is not pissing water in a stay stream.. It's intermentently coming out... Any reason as to why?... There's nothing clogging the lines either.... Just put new impeller in yesterday...thanks for help!!!!

 

[TKnittel]

Re: 9.8 hp merc carb cleaning/ tuning

Another question... Does my motor have a thermostat??? And will it only spit water when it heats up?... Thanks!