Jetting help.
Posted: 08:38 pm Jul 22 2012
I bought a very nice '98 KDX 200 off a guy I know. I haven't owned a 2-smoke since I was a kid, been on 4-strokes for a while so I'm kind of a babe in the woods with this bike but trying to learn.
He said it was jetted very well, ran great and my test ride it rode well...seemed to be awesome. But, on my first trip the trails I kept stalling on hills or after being on the throttle/in gear and clutching to a stop. Dead every time. If I turned in the idle screw enough to keep me running on clutch-ins, it reved to the moon cold or in neutral. And, the idle seemed erratic all day.
That sounded to me like a fuel starvation issue, so I tore into it tonight. Fresh fuel/oil mix (synthetic 40:1, 93 octane), fresh plug, fresh air filter, pulled the tank and cleaned the petcock. Inspected the reeds (perfect), pulled the carb and checked everything out as best I could (cleaned with carb cleaner, compressed air, pulled PJ and MJ, needle and float. The only thing I didn't check was the float level, not 100% sure on this carb how to do that...the manual was kind of confusing.
The jetting seems odd to me, but here's what's in it... stock motor (no mods), good compression (top end is pretty fresh, too). FMF Gnarly pipe, FMF power core 2, airbox drilled with 1/2" holes and snorkel removed. Elevation is 1,000 ft.
PIlot Jet: 48
Main Jet: 160
Needle: Clip in 4th slot from the bottom.
Air screw was out at about 1 3/4 turns.
Does that seem about right?
I tried following the jetting sticky as best I could, but even after re-assembly it's just kind of all over the place. The bike behaves very differently at idle once you're on it and coast...and no matter how well I thought I had it sitting in the driveway, once I rode it with some throttle and coasted clutch-in, it died.
If the jetting seems ballpark, anything I might look for? How about the float...is there a good "how to" on checking the level?
He said it was jetted very well, ran great and my test ride it rode well...seemed to be awesome. But, on my first trip the trails I kept stalling on hills or after being on the throttle/in gear and clutching to a stop. Dead every time. If I turned in the idle screw enough to keep me running on clutch-ins, it reved to the moon cold or in neutral. And, the idle seemed erratic all day.
That sounded to me like a fuel starvation issue, so I tore into it tonight. Fresh fuel/oil mix (synthetic 40:1, 93 octane), fresh plug, fresh air filter, pulled the tank and cleaned the petcock. Inspected the reeds (perfect), pulled the carb and checked everything out as best I could (cleaned with carb cleaner, compressed air, pulled PJ and MJ, needle and float. The only thing I didn't check was the float level, not 100% sure on this carb how to do that...the manual was kind of confusing.
The jetting seems odd to me, but here's what's in it... stock motor (no mods), good compression (top end is pretty fresh, too). FMF Gnarly pipe, FMF power core 2, airbox drilled with 1/2" holes and snorkel removed. Elevation is 1,000 ft.
PIlot Jet: 48
Main Jet: 160
Needle: Clip in 4th slot from the bottom.
Air screw was out at about 1 3/4 turns.
Does that seem about right?
I tried following the jetting sticky as best I could, but even after re-assembly it's just kind of all over the place. The bike behaves very differently at idle once you're on it and coast...and no matter how well I thought I had it sitting in the driveway, once I rode it with some throttle and coasted clutch-in, it died.
If the jetting seems ballpark, anything I might look for? How about the float...is there a good "how to" on checking the level?