How To ajust mixture

[snookin]

Hi, how would I know if the mixture on my 2002 Yamaha 150 ( Carb,) is set right? I have been going through a lot of oil lately and the plugs have been fouling dark black. Better to take it to my mechanic or is it somthing that someone with some common sense can do? - <br /><br /> Thank you, <br /> <br /> Hope all of you have a VERY SAFE NEWYEAR's & let's see you all back next year

 

[WillyBWright]

Re: How To ajust mixture

Idle mixture shouldn't affect oil consumption. That's run by a mechanical pump driven off the crankshaft and isn't tied to carburetion. But It does pump at different rates depending on the setting of the lever on the pump, and that is connected to the throttle linkage. The adjust ment could be off, or more likely the link rod is connected incorrectly. They're designed so that if the link is attached wrong or falls off, the pump will always pump at the richest setting. You can check that by looking for marks on the pump lever arm and a mark on the pump housing. A manual would be a real help and many public libraries have them.<br /><br />On most motors the idle mixture adjustments should be the same from carb to carb. But with many V-6 Yamahas those adjustments differ depending which cylinder the carb feeds. For that you'd probably need a factory manual and you might be able to pry information that from a Yamaha dealer. If you have a plain-jane Yamaha the adjustments are probably about the same on all carbs. For the Pro-Vs, you definately need the factory specs.

 

[snookin]

Re: How To ajust mixture

Thank you Willy B Wright, I'll give it my shot. But understanding your helpful info, back to the shop Thanks

 

[seahorse5]

Re: How To ajust mixture

The 150 has a carb setting of 1 turn on the idle screws. The S and L series use 1 1/4 turn. The D, P, or V series need 1 1/16 turn on the port side and 1 9/16 turn on the stb. That is why a model number is very important when asking about service information.<br /><br />Also make sure the oil link arm is adjusted per the manual and that the thermostats are allowing the motor to warm up to about 140 degrees at idle on both cylinder heads.