how to lean blackmx 150

[crazyhunter]

i have a blackmax 150 83 model that is running to rich im seeing unburnt oil on the plugs and its smoking more than it should. how do i lean it out just a bit?

 

[Texasmark]

Re: how to lean blackmx 150

The only thing at your disposal is the idle mixture screw on the side of the carbs. Screwing cw leans the mixture, but only for low speed operation. High speed is fixed jet. I'd consult the repair manual to do it right as some engines (like mine) are real sensitive to idle timing and carb settings. Maybe you need to clean up your engine with some Sea Foam, or do a "decarb" as detailed many places in this forum. Do you do a lot of idling, or trolling?

Mark

 

[gbrowne9]

Re: how to lean blackmx 150

i dont think the v6,s had idle mixture screws.they have air bleed jets in the center of the carb fronts.i have a 1988 135 that i disconnected the oil injection on and the cheepest way to modify the jets is to drill them out.you need to see what size they are and get some indexed drill bits for .03-.04 increments.my jets were .94 and i drilled then out to .97 and it worked very well.the motor would not accelerate out of the hole .if your motor was running well before maybe you have a carb problem,sunkin float,needle/seat stuck.

 

[crazyhunter]

Re: how to lean blackmx 150

ok ill run some seafoam through it and see what happens

 

[Faztbullet]

Re: how to lean blackmx 150

There are no adjustments on your carbs as they are fixed jet design, the likely problem is the check valves on the bleed/recirc system as stopped up or bad.

 

[CharlieB]

Re: how to lean blackmx 150

Do NOT drill out any carb jets, you will screw off thousands of hours of R&D spent getting that motor to run reliably.

I don't put a lot of value in chemical 'fixes'. SeaFoam can do wonders in cleaning carbon deposits out of ringlands, but as for cleaning carbs, there ain't no comparison to taking them apart, cleaning them, blowing all passages out with a good solvent followed by compressed air.

Remember carb kits are cheap, as is the fuel pump rebuild kit.

Check your fuel hose, older hose has a nasty habit of the clear lining half melting, sloughing loose and clogging fittings, fuel pump, and carbs.

Like Fazt pointed out, the recirc system needs attention, you can use alcohol and a hypodermic syringe to flush each line and test the check valves.

Once everything is cleaned and dialed in following the FACTORY service manual you should expect your motor to run fine.

Repost your progress and/or any problems you find.

 

[crazyhunter]

Re: how to lean blackmx 150

ok thanks for the advice ill post the results. we are taking it out sat night for a all night crappie/catfish trip.