By terry harrison (Th3) on Unrecorded Date: Edit

i have a 02 max iv with the 25 kohler. the engine is running rich - sooty pipe and sooty plugs. i have the shop manual for the engine. the manual shows a pic of the carb with an arrow showing the location of the air/fuel screw. on my carb the location is covered with a metal cap that is pressed into the hole where the adj. needle should be. i cant find any adjment on the carb to lean out the air/fuel mixture. i did find a empty threaded hole at the base of the carb, to the lower left of the low idle speed adjustment cam & screw, located on the rear of the carb under the choke lever. is something supposed to be in this empty threaded hole? like the adjustment screw im looking for?

By Attex Bob on Unrecorded Date: Edit

Terry, the A/F screw is probably going to be under the cap. I don't know the Kohler at all, but it is a common trick on car carbs to do this. This was done so you can't monkey with the A/F ratio and screw up the emissions (or fix them!!!)

Maybe Fred or somone on this board can tell you if I'm right?

By Fred Sowerwine, Montana's Max dealer (Fred4dot) on Unrecorded Date: Edit

Terry, Have you checked to make sure your choke is opening all the way? Personally, I wouldn't fool with an engine that is still under warranty (I think your screw is under that cap); I would take it to a Kohler service center.

By shane forsythe (Shanefor1) on Unrecorded Date: Edit

terry,
dirty old plugs can also cause sooty exaust, have you checked them???

f#$%^* the pollution laws tune it for power, if you want power, take to a carb specialist.

or leave it alone if you want to go a long way on 1 tank of fuel.
the choice is yours.
shane.

By terry harrison (Th3) on Unrecorded Date: Edit

plugs are brand new bosch +4. the choke is operating as it should. the cable is tight, in the latch on the carb, and the butterfly is fully open.

i found out that the cap is installed over the a/f needle. the cap has to be drilled and removed with a small screwdriver to access the needle. i didnt remove the needle the first time i cleaned the carb. i guess i need to remove the needle and clean the carb again. i also found out that the empty threaded hole at the base of the carb is supposed to be empty.

By shane forsythe (Shanefor1) on Unrecorded Date: Edit

terry,
yeah there could be cr#p in the air fuel mixture area, as that wasn't taken out,
count the turns toput it back right , the slightest difference changes performance a lot , but you knew that.
shane

By terry harrison (Th3) on Unrecorded Date: Edit

after talking to my local kohler dealer i discovered i didnt have the float set correctly. the extra fuel in the bowl was sloshing around spilling into places it should not have been. the service manual states "hold the carb air horn so the float hangs virtically and rests lightly against the fuel needle. the fuel inlet needle should be fully seated but the (spring loaded)tip should not be depressed." this does not work. the fuel level is still too high. i was instructed by the kohler dealer to hold the air horn upside down and the float should be parralell with the horn casting, fully depressing the spring loaded tip. after doing this the fuel level was dropped to a point that prevented fuel from spilling into the intake and causing a rich mixture. my spark plugs burned off the sooty build up and the motor missing on hard turns and rough manuevers has stopped. BUT.........

i was able to remove the metal cap over the air/fuel needle without any trouble. used a small o-ring pick to lift the cap out. upon removing the needle i found "stuff" on the needle and spring. it was not gritty like sand, i think it was just some type of sealer that was put there to hold the metal cap in place. im still working on getting the carb set right. it runs great on top end but backfires every now and then when i get back on the throttle, and some times the motor tries to bog and die when i crack the throttle after a rev down from full throttle. i have killed the motor by cracking the throttle after rev down. im following the instructions in the service manual to set the air/fuel needle but its not working. if this keeps up i may have to adjust the carb settings with a claw hammer.

By terry harrison (Th3) on Unrecorded Date: Edit

ok,
i dont know what this carb is doing but i finally got it to act right. after taking it apart and cleaning it with b-12 , blowing it with compressed air and putting it back together , three times, it finally started doing what it is supposed to. i dont know what i did to fix it or what the problem was. all i know is that i hate it.
i went on a ride today and burned half a tank of gas and really didnt have any problems except a little backfire when i get back in the throttle during aggressive maneuvers, other than that it is running better than ever. i guess the new air filter and bosch +4 plugs make a nice difference. ups dropped off the spring kit, for the drive and driven clutch, yesterday, but since it is running so well, im going to ride it a while before i install it.

By shane forsythe (Shanefor1) on Unrecorded Date: Edit

terry,
the air /fuel needle must of had old sh#t fuel build up on it .
did it appear milky?

By terry harrison (Th3) on Unrecorded Date: Edit

no. the factory put some kind of glue or sealer on the metal cap to hold it in place. that sealer ran down into the needle treads and spring and dried. when i turned the needle to remove it the sealer flaked off into a soft white flakes. i removed all the sealer the first time i cleaned the carb yesterday and it still was acting up. im not sure what i did to fix it. the last two times i took it apart and put it back together it looked like new. i dont know......... this is why i dont like working on carbs. i cant figure them out. i guess i need to go to carb school.

By shane forsythe (Shanefor1) on Unrecorded Date: Edit

terry,
yeah that's why they put warranties on things,
if your's is still under warranty get the dealer to fix it,
if not the dealer / factory probably have a trick to fix it so pay a bit now and save yourself some trouble in the long run.
shane