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AQ131 carb float adjustment?? is this required?

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beeton

Member
Penta aq131, new plugs, wires, coil, cap, rotor, carb rebuild.

I have the above model with the older Solex carb. Rebuilt the thing twice and I just could not get it to idle. My son and I were cleaning up things yesterday and took another look at the carb. We could get the boat to start and rev above idle BUt not idle.
At idle, there seemed to be no fuel atomizing out of the main jet. The accel pump worked. We took off the main jet and noticed the fuel level was level to the top of the main jet set (engine off) and the boat did idle.
Seemed there was not enough pressure pushing fuel up the main jet tube? The fuel pump was checked and the output was strong.

So, I had a look at the float... no holes. I bent the tab down slightly to increase float level and the boat idled better.

But, I do not see any reference to float level in any searches except one claiming no level adjustment is needed.

Am I on the right track here?

if I don't get this ready for the water by July 1st, out she goes as I do not need such a large lawn ornament.
 
Ethanol in fuel can cause hard deposits to form in small passages like idle jets. These deposits do not dissolve in any cleaner I've found but only respond to mechanical removal ( I use an appropriate size number series size drill bit held in a pin vise). Alternatively, I've heard that the pros dump the carbs in an ultrasonic cleaner which is effective in breaking up these deposits.
 
i O.K. Cleaned it out again. Straightened out the float arm. Starts not too bad but I just cannot get that idle right.
When cleaning it out, I dressed the mating surfaces with a file as there was some warping of the bottom flange.
I turned the mixture screw in 2 turns and this is where the confusion starts:
The diagrams I have found clearly show the mixture screws but there is no mention of the acc pump screw setting or the throttle cable setting and these may be causing problems. The "idle" screw, connected to the accell rod assembly, if I am correct, also seems way too open when I turn that out 2 turns.
I'm screwing something up here.
Pictures attached.

Solex 44 (1).jpg

Solex 44 (2).jpg
 
Ayuh,..... The 2 turns on the adjusting screws are just a starting point, not a final setting, which is done to get the best idle possible, usually by ear,......
 
Yep. I have tried in and out from the 2 turns but i am wondering if the other settings (throttle rod, pump) are off and throwing things off. If so, I can fiddle with the mixture screw forever and not get this running properly. the manuals have no reference to the correct settings for the throttle rod and pump rod.
 
The throttle rod is what sets the actual idle RPM, the mixture screw influences how smooth the engine runs @ idle so the kind of interact. The accelerator rod controls how much fuel is dumped into the throat of the carb when you want to accelerate (in gear).
 
O.K. I thought so but the setting for the throttle rod (the long one with spring) may affect the idle regardless of what you turn the throttle screw to. This is the initial setting I do not have. Similar to my motorcycle.. "adjust throttle cable so there is 1mm of slack before the throttle is affected..." for example.
 
beeton said:
O.K. I thought so but the setting for the throttle rod (the long one with spring) may affect the idle regardless of what you turn the throttle screw to. This is the initial setting I do not have. Similar to my motorcycle.. "adjust throttle cable so there is 1mm of slack before the throttle is affected..." for example.
Click to expand...
Mixture setting is fine tuned by ear or set using a manifold vacuum guage. Throttle rod is the primary setting for idle RPM even thought the idle RPM once set will vary with the idle screw.... hence the gauge. You end up resetting the throttle rod adjustment again after getting mixture set.... assuming timing and dwell are OK.
 
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