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1992 9.9 carburettor problems

E

Eric Hoare

Contributing Member
I have trouble starting my engine even after it has warmed up and ran previously. when it is running it is great. i have had the carburettor off several times and checked most of the valves and they seem ok. It does not have a manual choke but does have a small rubber pipe going into the lower left hand corner which I thought to be an automatic choke but have been informed that the engines either have a manual or electrical choke.
Sometimes if I put my hand over the air intake it starts but not every time. The lean/rich mixture screw is of the finer thread which I was told has to be turned out 4.1/2 turns unlike the course thread which is 1.1/2 turns but even altering this has had no effect.
What is this small rubber pipe for?? it's not fuel as that is a larger one a little further up the casing.. Most confused Please, can someone explain.. Many thanks... Eric
 
Eric..... Your initial post which listed no year was inserted under another members 1979 engine post which had me quoting that your engine would have either a electric or manual choke. Now I see that your engine is a 1992 model 9.9 which is a different fuel setup as follows.

Your engine does not have a choke per se at all but rather has a fuel primer solenoid.... a BLACK solenoid with a RED lever on one end of it (explained in detail below). That RED lever must be set so that it points at the other end of the solenoid which puts it in the "automatic" mode.

(Fuel Primer Solenoid Function)
(J. Reeves)

The RED lever...... The normal operating/running position is to have that red lever positioned over top of the solenoid and aimed at the other end of the solenoid, gently turned to its stop. This is the normal/automatic mode position. Pushing the key in opens the valve within the solenoid allowing fuel to pass thru it in order to prime and start the engine. Looking upon this solenoid as a electric choke results in a better understanding of it.

Having that red lever turned in the opposite direction, facing away from the solenoid, allows fuel to flow thru it to the crankcase area. One would only turn the red lever to this position in a case where the battery might go dead and the engine had to be started via the rope pull method. Look upon putting the red lever in this position as moving a choke lever on a choke equipped engine to the full closed position. Either one would supply fuel to the crankcase/engine for starting purposes BUT if left in that position while running would flood the engine.

The later model primer solenoids are equipped with a schrader valve, used for attaching a pressurized can of fogging oil etc, available at your local dealership with complete instructions.

Pumping the fuel primer bulb up hard fills the carburetor float chambers of course, but that process also applies fuel pressure to the primer solenoid.


The two small hoses leading from the primer solenoid branch off via tees to each fuel manifold section that would feed fuel to the individual cylinders.


Pushing the key in activates the primer solenoid to allow fuel to flow thru it to the intake manifold passageways. Cranking the engine over causes the fuel pump to engage which in turn sends fuel pulses to the primer solenoid via the 3/8" fuel hose.


Some engines incorporates the "Fast Start" feature which automatically advances the spark electronically so no advance of the throttle is required for starting.
Engines that do not have the "Fast Start" feature will be required to have the throttle advanced slightly.


Starting procedure: pump fuel bulb up hard, crank engine and push the key in at the same time. When the engine fires/starts, release the key so that it falls back to the run position.


Bottom line..... Look upon the primer solenoid as an electric choke.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:

http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
********************
 
You are a star Joe, we hadn't a clue what that red leaver was for only that if we turned it the engine would stop. We also wondered why there was, what looked like a car wheel valve cap on it. I will check all your information when I go down to the workshop, maybe then it will start properly.
Was I right about the lean/rich screw???
Thank you once again.
Eric
 
(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.


When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
 
Eric Hoare said:
We also wondered why there was what looked like a car wheel valve cap on it. Was I right about the lean/rich screw??? Thank you once again. Eric
Click to expand...

That valve stem thing (car wheel valve cap) is for spraying in various chemicals for fogging (winterizing) and/or getting rid of carbon build up etc... stuff available at any dealership.

The slow speed (lean/rich) needle valve info inserted above somewhere.
 
Hi Joe, The key switch didn't press in due to there being no keys when I bought the engine and had to drill it out although the purple wire that feeds the solenoid is there attached. i also checked the primer solenoid but that wasn't working either even connected direct to the battery. The internal plunger didn't retract to allow the fuel to travel up the small pipe. So I will need both the key switch and solenoid. Do you have any? even second hand providing they work?
 
Sorry to say that my remaining stock was sold out of most electrical items rather quickly.

If the primer solenoid ground wire is attached to the power-head and you apply 12v to the hot lead of the solenoid, you should hear a click. Note that the electrical feed does not cause the RED lever to move, the movement is internal.

To check the solenoid, there's a small feed hose that leads from that solenoid to the carburetor or the intake manifold. Temporarily remove it from the carburetor or manifold, pump the fuel primer bulb up hard... no fuel should leak from that small hose at this point.

Apply voltage to the solenoid's feed lead. It should click and fuel should shoot out of that small hose.

NOTE: Do Not have that small hose aimed in the direction of the sparking voltage jumper wire! BOOM! :cool:
 
I did try all that and it didn't click or squirt any fuel, do you know if you can removed the internal parts? the little rod and springs that move down to open the small hole in the top. I am thinking that the metal rod may be rusted or stuck which gives the click sound. Its only an electro magnet that when activated with 12 volts causes the mechanism to drop down. I have seen them in sites but they are about $200 which when posted to UK (where I live) with our greedy government adding another 20% would cost me a fortune..
 
Eric Hoare said:
I did try all that and it didn't click or squirt any fuel, do you know if you can remove the internal parts?
Click to expand...

Yes, everything that makes up that fuel primer solenoid can be purchased separately. I just checked my remaining stock for the assembly and parts... sold out of course (never fails). However, all of the components are available.
 
I finished up having to replace the solenoid as when my mate (so called) drilled out the key switch he left it in the prime position so power was going into the solenoid permanently which overheated the coil and melted the internal parts. Parts should arrive today so should have it working by this afternoon. Will post how I get on..
 
Well, thanks to Joe and his expert advise the engine is now running perfectly, the minute I replaced the key switch and primer it started up straight away. it is now back on the boat and performs like a dream..
Thank you Joe...
 
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