Two Stroke Motocross

Two Stroke Motocross Forum => Technical => Topic started by: thorns on March 31, 2013, 09:14:15 AM

Title: 2008 RM250 jetting
Post by: thorns on March 31, 2013, 09:14:15 AM

Could anyone reccomend some jetting specs for my bike?
Its standard apart from FMF rear muffler, and v force moto tassinari reeds in it.

I have no idea what is in there at the moment, but keen to have a look.
Hasnt been fouling plugs regulary, but they are coming out pretty black.

On this chart here, they would be closest to the dry fouling picture
http://www.alfabb.com/bb/forums/attachments/anything-about-alfa-romeos-alfabb-com/9852d1100019475-spark-plug-color-chart-spkplg_colorchart1.jpg

Title: 2008 RM250 jetting
Post by: thorns on March 31, 2013, 09:16:11 AM

Should also add I am running NGK BR8EG, or BR8ES when I cant find a EG.

Title: 2008 RM250 jetting
Post by: rm250guy on March 31, 2013, 09:51:34 AM

are you in a hot climate or cold?  Sand or hard pack?

Title: 2008 RM250 jetting
Post by: thorns on March 31, 2013, 07:28:00 PM

Will be running in temps from 10-20 degrees celcius, and both sand and hard pack dirt.
ALso, running near enough sea level 95% of time.

Title: 2008 RM250 jetting
Post by: rm250guy on April 01, 2013, 05:53:38 AM

damn that is pretty cold..   I am at sea level here and ride in 20-40deg temps.  yep, it is the desert here.

for the 20 deg I run a 168 main, with a necH needle in the 3rd position, stock pilot.  the bikes both have vforce and PC pipe and silencer.  In the hot summer i usually drop the main down to a 165.  for your 10 deg weather you may need to richen the main to a 170 or 172.  the bikes both have a flywheel weight which helps with hook up on the hard pack and overrev...  the flywheel weight is the lightest available for the RM from steahly... 6 or 8 oz i think.  I hope this helps

Title: 2008 RM250 jetting
Post by: thorns on April 01, 2013, 11:55:39 PM

Thanks for that.   Yeah we are just about to enter winter (sigh), otherwise summer is 20-30 degrees.
Are needles marked on them what they are?   I have no idea what the current jetting is, so be interested to get my hands dirty and have a look.
Bike is going to be out of action for a couple of weeks now anyway as I need to do fork seals after easter weekend riding.

Title: 2008 RM250 jetting
Post by: rm250guy on April 07, 2013, 08:58:25 AM

no prob for that... yes, the needles are marked down the side.  Do you have a manual for the bike?  If not it would be good if you could get your hands on one.  There is a lot of good info there,,,,  Also MXA and Dirk Bike magazine have some good articles on the 08 Suzukis.

heading into summer here so it is already in the mid-30s, soon it will be in the mid-40s....