Need some input, 2003 RM250 Jetting suggestions?
I just purchased an almost new 2003 RM-250. The bike has probably less than 5 hours on it, its in immaculate condition. The only mod is an FMF Fatty pipe/shorty silencer.
On the test ride, the bike left some spoog residue on the fender, but it felt strong. Once I got home I checked the plug, it was a NGK BCPR5EY. I changed to a BR8EG, drained the fuel, and mixed a fresh batch. I still got some residue on the fender.
After reading the article from Rich about plug reading, I decided to cut the plug. The carbon ring is all the way
up the insulator, with only 2-4mm's at the tip golden. I think its safe to say the jetting is rich?
What would be a good baseline to start from?
Current Jetting;
Main Jet #175
Needle N8RH-3rd
Slow Jet #48
Air Screw 1 1/2
Power Jet #50
Fuel: Sunoco 93 octane(pump super) @ 40:1 w/ Golden Spectro semi sythetic.
Altitude: 200-500 feet above sea level.
Type of riding: Mostly MX, I am about an average yet aggresive rider.
Thanks, Steve.
I just purchased an almost new 2003 RM-250. The bike has probably less than 5 hours on it, its in immaculate condition. The only mod is an FMF Fatty pipe/shorty silencer.
On the test ride, the bike left some spoog residue on the fender, but it felt strong. Once I got home I checked the plug, it was a NGK BCPR5EY. I changed to a BR8EG, drained the fuel, and mixed a fresh batch. I still got some residue on the fender.
After reading the article from Rich about plug reading, I decided to cut the plug. The carbon ring is all the way
up the insulator, with only 2-4mm's at the tip golden. I think its safe to say the jetting is rich?
What would be a good baseline to start from?
Current Jetting;
Main Jet #175
Needle N8RH-3rd
Slow Jet #48
Air Screw 1 1/2
Power Jet #50
Fuel: Sunoco 93 octane(pump super) @ 40:1 w/ Golden Spectro semi sythetic.
Altitude: 200-500 feet above sea level.
Type of riding: Mostly MX, I am about an average yet aggresive rider.
Thanks, Steve.
Last edited: