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View Full Version : Help me jet my 250r...just a little off???



blubyyou
09-21-2006, 10:12 PM
I need a little help jetting my 250r out. It's an 88 engine. Mods include a paul turner race pipe, fat boy silencer, boysen reeds, kn filter with outerwear and open air box, and a 38 mm A/S carb from ESR. I had to turn up the idle screw a little to speed up the idle to keep it running a litttle. The bike feels good and doesn't miss or anything at all...it just feels like it has a narrow powerband and falls off on the very top and doesn't keep on revving out. It came with a 50 pilot jet and a 178 main ...the plug was a little black but not wet after an hour of riding. I jetted up to a 185 main and rode for a couple of minutes and realy didn't notice a change. My friend recomended going up on the main size. I almost think I need to step down below a 178 main a size or two? I run maxima 927 oil at 32:1 with 93 octane and I'm right at 2000 ft. elevation. Maybe it's just the nature of the beast with an R ...this is my first one. I used to have a banshee. Also I was thinking maybe it was just the pipe and set up I have...I want it set up for MX so it's mostly mid range....but I'd like to be able to rev it out if I need to on the track if I needed to just a little extra. I'm running a br9es ngk plug...I have a couple of br8es plugs if this would make any difference at all. Please help me in the right direction....I gotta get this thing dialed in for this weekend! Thanks in advance!

EXtreme-
09-22-2006, 05:59 AM
switch to the br8es

running 927 at 32:1 is like running molassas thru your piston. I wouldn't be suprised if you have black crap dripping from the tail. I run it 50:1 with excellent results. Used to run it 40:1 and still was too heavy.

the 178 is close. I'm using a 175 with almost the exact same setup. splitting hairs, that close. I ride 1200 to 2000ft

any idea what needle they gave you for that carb? I'd like to know if you can pull it. Very curious!

blubyyou
09-22-2006, 05:20 PM
I'll swich plugs to a br8es and go to a 178 at 50:1 and hope this help....I'll check the plug and see what's up. Hope this helps a lot on my topend power dropping off.