Does anyone know if the BSR Mikuni carb on the Predator 500 have a adjustable fuel mixture screw? Putt

 

Just in case anyone was interested, yes it does. I got brave and took the carb to the drill press and drilled out the plug where I thought the adjustment screw is. Plugs gone and adjustment screw is there. Factory has it three and a half turns out . I'm going with the W/B slip-on, Jet Hot Coated head pipe. Carb mounted K&N air filter with outerwear, 160 main jet, 4th groove on needle, 2 1/4 turns out on the mixture screw. Well see how it runs (as soon as my header gets back from Jet Hot Coating [img]i/expressions/face-icon-small-sad.gif[/img] Later, Putt

 

G'day Puttnutt. Mate, that takes ***** to do what you did to the carb, I admire that & carn't wait to hear all the results. Thanks from down under Geoff.

 

Most of the 600/700 owners who ride in below freezing temps know about the problems encountered by not readjusting the idle fuel mixture screw you are talking about. On the 600/700 it comes from the factory at 1 1/2 turns out and needs to be at 2 turns for proper operation in the cold. I really would like to know, WHY THE #$%^ DID THET PUT AN ANTI TAMPER PLUG IN. I also had to drill mine out to adjust it, runs fantastic now.

 

Excuse my ignorance, but what exactly does this screw do? Does it adjust the amount of fuel is mixed with air? Could you get better fuel mileage from the ATV if this is adjusted?

 

It is an idle mixture screw and adjusts the quantity of fuel to be mixed with air and will only have an effect on idle and a little above. I doubt it can improve your gas milage. My symptoms were: (don't forget, I'm talking about below freezing temps) Started no problem, would'nt hold idle during warmup(yes I know how to use a choke) Took 20mins or more of riding before it had good throttle response.(flatspot when giving it the gas, sometime very severe)

 

is it on the left side of the carb or the right?

 

Under the float bowl Part#31 600/700 Carb
Unfortunately you can't get to it without turning the carb 90 degrees or removing it.

 

So this could explain the raw gas smell I seem to get every dang time I take my 700 out? It seems the speed at which we travel does not matter either. My wife took me out on it last week, and the bike reeked of gas when we got home again. I took it back toit he dealer...but he has no way of testing it...and says it is due to the WINDSHIELD!!! grrrrrrrrrrrr

Has anyone else experienced the smell of raw fuel after driving it?

am I driving it to hard?

could it be the windshield?

 

Drain the carb bowl first. Do this by backing off the Philips screw on the bottom of the floatbowl. It's the screw just above the smaller diameter clear hose. You can catch the fuel at the hose outlet so it doesn't go all over. By taking the carb loose from the boot (loosen the hose-clamp). You can rotate the carb. With a 1/8" bit in a drill, drill the small brass plug just in front of the floatbowl. Drill carefully, and before you're through, the plug will normally catch and spin itself out. Works for adjusting the mixture in the idle-1/4 throttle range. Turning out leans, and turning in richens.