I am "rebuilding" my evinrude 9.9 carb. I have the kit an would like to know if a schematic is available online. Or instruction. I see many are working on these lately. Could use direction.
Matt / Miami
"Matt... The important thing is to make notes if you've never done this before. Something so simple as which way a lever might face might seem like something one would never forget, but five minutes later would be quite confusing. I still make notes and draw pictures of unfamiliar things such as say the magneto system of a riding lawnmower when taking it apart.... it does come in handy.
I don't think you've mentioned what year your 9.9hp is. If it's one of the eariler models, the high speed jet is a fixed brass jet that is screwed into the bottom center of the upper portion of the carb body. That must be removed and cleaned thoroughly, and of course reinstalled. Much of the work in self explanatory such as what gasket goes where etc. The small tab on the float faces the upper carb body, and when the float & needle valve assy are assembled, hold the upper carb body upside down and adjust the float so that the far end of it (the end opposite the hinge) is ever so slightly higher than level (on a "very" slight incline as compared to the surface of the carb body surface). If you have the later model carburetor, let me know.
After installing the carb, making sure that you have the "red" nylon s/speed needle valve retainer installed in the top front of the carb, screw in the s/s needle valve until it seats (do not force it...seat it gently). Now, back it out about 1 1/2 turns. Start the engine and set the throttle whereas the engine will stay running. Slowly turn in the s/s jet in 1/8 turn segments. As you do this, the rpms will climb. Back off on the throttle to a idle just where the engine will stay running. Repeat this procedure until the engine either starts to die out or it spits back (sounds like a mild backfire). At this point, back out the s/s jet approximately 1/4 turn. At some point in this 1/4 turn, you will find the area where the engine runs smoothest at idle. If you cleaned the carb as it should be, the high speed will take care of itself. Let us know in this thread how you make out.
" Joe-
I rebuilt. Problem. I am flooding after about 1 minute run time ( or less ). The motor bogs, dies, then will not restart until it "drains" out. Did I miss something? Any help is appreciated. "
"Matt.... Remove the plastic top cover from the carb air intake, then pump the primer bulb. If you can see fuel being forced out of the carb, then yes, you've missed something and you'll need to remove the carb to check your work as per my above instructions.
Note that the lower plastic portion of the air intake has a small circular portion that must sit within the matching hole (air vent) in the front of the carb.
If the fuel is not forced out at the carb area, then I would suspect that the fuel pump diaphram is ruptured and if so, the fuel pump will require replacing. To check the fuel pump, remove the two screws that retain the pump to the powerhead, then put nuts on the ends of the screws and tighten them. This will make the pump tight at all four corners and you will be able to view the back of it. Pump the fuel primer bulb. If you can see fuel being forced through the hole in back of the pump, the pump is faulty.
This type of fuel pump failure allows fuel to be forced directly into the crankcase area which loads the engine up excessively with fuel.
I did the "pump test" and fuel flowed out. Any quick thoughts as to why? I double checked the float valve...seems ok. >> Other thoughts? It is a 1980 model.
"Matt... When you say you did the pump test, I assume you mean that you "pumped" the primer bulb and fuel flowed out the carb. If so.... either you did not install a new float needle valve assy, or you neglected to install the nylon washer under the float valve seat, or you have the float installed upside down or off level.
With the carb off, the bottom off and the float exposed, (holding the carburetor upside down), the small flange on the float hinge should face the float valve area. The float should be ever so slightly higher than level as compared with the upper body surface.
