Dirtman500

Member
Jan 8, 2004
70
0
What kind of oil are you running?
What mixture ratio? Are you measureing oil with say a ratio rite cup?
Are you fouling plugs?
*** Your better off running a little rich rather than to lean!
For starters look at the type of oil you are running! I have seen alot
of bikes foul plugs left and right with decent oil then with hardware store
2 stroke oil foul a plug in as little as 10 minutes. If fouling sparkplugs is an issue try a different oil first and also make sure your using the correct sparkplug! NGK or ND! Try this first: Forget the carb and make sure your airfilter is clean, replace plug with brand new plug, and now for the kicker... The different oil! Oil of choice that I run @ 32:1 is Maxima 927.
What a change it made for me and others. Now run you bike and don't be suprised if you go all day on the same plug! Ok if you foul the plug start by moving your needle clip first. (One Groove) Leaner! *** Check this out:
A person that rides with me on our weekend rides is a very very very slow rider. A YZ250 can't be rode like a moped all day! Well I told him to drain the garbage gas/oil mixture out and even drain out the float bowl and then we filled it up with my 32:1 mixture of 927 and low and behold he rode that
complete tank through his YZ at the same slow pace and never fouled a plug!
*** When I took my engine apart I couldn't beleive how clean it was! Real Clean! Give it a shot you'll see!

moped (oops!)YZ all day on the same plug!
 

HOMEFREE

Member
Jan 13, 2004
3
0
The bike is all factory. I live in Northern MN so i'm not sure what the ALT.is up here for carb adjustments. The bike came with a 195 main and a 50 piolet, I'm also running Justice Bros oil mixed 32@1. I'll tell ya there is no west nile virus up here when i start this bike up it's just like a crop duster no bugs around for miles.
My friend has a 2001 RM 250 and his bike flies so i put the same size jets in mine that he has in his (170 main 48 piolet)and it made mine better but it still fouls plugs.
Before i did any carb changes the bike would spit black spooge all over the back, down the pipe every were, I went thru a box of plugs in like a week. The plug # is a NGK BR7EYA if this helps. My friend said that he read in a magazine that if you own a 2003 RM 250 to trade it in for a 2004 because the 2003's are to much work trying to dial them in. Has any body else seen this? The only thing that i don't like is the seat it's like sitting on a 2x4.
 

Okiewan

Admin
Dec 31, 1969
29,555
2,237
Texas
You can't possibly get jetting close without knowing altitude, temp, using consistent quality fuels, etc ... jetting changes from typical winter to summer temps.

As far as dumping a 03 RM ? Never heard of such a thing, sounds like typical magazine spew. The mags also recommend jetting to match their So-Cal location, no matter where you live. Tip number one, look at the pics in mags, do not read anything.
 

zookieman

Member
Jul 7, 2003
118
0
2003 SUZUKI RM250
Main...165
Pilot...45
Needle...stock
Air screw...1 1/2 turns

These adjustments worked well for me I live in Michigan. Don't listen to those Magazines, the jetting isnt that tricky. My 03rm250 was spooging like hell and fouling plugs like crazy until I made these adjustments. Now I have nearly no spooge and have not fowled a plug since. Next season im goin to move the clip to the 2nd position on the needle to lean it out more. Trust me once you get it dialed in it will RIP.
 

210zook

Member
Jan 14, 2004
9
1
I have an 03 RM 250 and live in Arizona, but the problem I have is my bike runs lean. I've got a Pro-circuit pipe/silencer, No Toil air filter, run 91 octane pump gas mixed at 32:1 (Yamalube). Elevation is about 1500', temps are between 60 and 70 this time of year. The bike seems to run lean from 1/2 throttle to full throttle. I am 1 step leaner on the pilot(45), one leaner on the clip(2nd), and way rich on the main, from a 175(Stock) to a 185/190. Any suggestions?
 

HOMEFREE

Member
Jan 13, 2004
3
0
Thanks every body I'm going to try that 165 main like zookie has I think that will work a little better than what I have in it now (Main 170) Just because with the 170 I still fouled plugs. It RIPS good now and at top end it don't sound like it's starving for fuel, so I think the 165 will work o.k. I have a buddy that lives by Justice Bros. 2 cycle oil. Is this a good oil? kinda expensive though, like $4.00 a shot
 

zookieman

Member
Jul 7, 2003
118
0
Actually thats cheap compaired to what I use, ands it may be a little bit overkill, but I use BELRAY synthetic @ 32-1. It is supposed to be the best. It is about $8 a Qt. also I use %50 race fuel from Sunoco 110 octane. and %50 percent regular high octane pump gas. Just in case you wondered I use the stock pipe and a FMF silencer with spartk arrestor.
 
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