Merc 9.9hp Carburation

[AndyL]

G'day All,<br />I have inherited a 9.9Merc. Ser No 9472893.<br />Not sure what year it is.<br />I can get the motor running but it will not idle no matter how I set the mixture screw. I believe the carb has been apart before and am looking for the setup info regarding float height etc. No, I have not bought a manual as it would likely cost more than I paid for the motor. Any help/ advice appreciated. Thanks. Andy

 

[steelespike]

Re: Merc 9.9hp Carburation

First if you are going to keep this motor get a manual, it is worth almost any cost.<br /> This is from a 72-84 Clymers manual<br /> Float drop measurement with carb inverted should measure 1/4 inch +/- 1/64 from float bottom to casting.<br /> with carb upright should measure 1/16-1/32 from bottom of float to fixed jet.<br /> I was lucky but I paid only $4.00 + shipping<br /> for my unused Clymers manual.<br /> Check ebay for an after market manual it might surprise you.Also the library may have one.<br /> Good luck.

 

[AndyL]

Re: Merc 9.9hp Carburation

Good on you Spike,<br />I am going back into battle. Should I be able to get it going I will promise to invest in a manual. There has been so much else wrong with the motor that leads me to think it is a lemon.And that investing in quoted prices of $60+ of your money for a manual was a bit over the budget range, if in fact I should not waste my time in the first place.<br />Thank goodness for people like you taking the time to look this data up.<br />All the best<br /><br />Andy

 

[AndyL]

Re: Merc 9.9hp Carburation

Update>><br />Had the motor going for a while but then fuel started pouring into the venturi throat. Dissassembled again and replaced the needle valve and float. Does not have seemed to cure the problem. I assume the seat in the carb must be damaged in some way as I cannot constantly get a seal. Suppose that really is the end of it as the seat does not appear to be renewable. Hey Ho. Stress is a 2 stroke!!