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renegade805
04-29-2011, 07:22 PM
Seems week 05 28d slide 142 45 pod air filter screw 2 1/2 out stock motor and pipe with 15/48 gearing. Weak bottom seems to need alot of clutch and gas just to go. Mid and top not bad. Need to adjust? Jetting gearing maybe 48 pilot? ??? Any help

renegade805
04-29-2011, 07:45 PM
Doesn't seem to have that clean crisp snap barely wants to get out of 1st

FISH ON!
04-29-2011, 08:14 PM
Your jetting is in the ball park for a stock motor. Might be time for a top end rebuild. Check compression and plug chop.

renegade805
04-29-2011, 08:19 PM
Compression is 145 haven't done plug chop yet. Can't see why it takes so much effort to get rolling out of first maybe gearing?????

otteboys
04-30-2011, 07:19 PM
Gearing seems kind of tall for a stock motor.

FISH ON!
04-30-2011, 08:03 PM
I agree with otteboys. We run a 14-48 and a 14-50 in the woods.

renegade805
04-30-2011, 08:15 PM
Was thinking of running 13/48 instead of 15/48 to see if bottom wakes up. Mx application

otteboys
04-30-2011, 08:33 PM
We run a 14/48 for mx with a built 07 motor and pipe, thinking of trying 13/46.

renegade805
04-30-2011, 08:43 PM
Again that's with me on it at 210 my sons about 100 in riding gear .it pulls hard mid and top with me on it.he needs a little more bottom for coming put of corners. Maybe ill try both 14 and a 13. Don't want to sacrifice my mid or top.what chassis you running

otteboys
04-30-2011, 09:00 PM
JB chassis. Keep in mind these motors don't have a lot of low end, you really have to keep them wound up.

renegade805
04-30-2011, 09:07 PM
Blaster chassis had a 260 stroked and poked national motor.yeah 85 is a little different. I kept the motor for when he's ready

doonanracing
05-01-2011, 05:25 PM
We run 13/47 or 46 for MX on a built motor inside a Fischer mod (same as JB) and he can pull the front wheels up coming out of the corner in 3rd gear and has never had a top end power issue where he ran out of gear and that seemed to elliminate any bottom end issues. The only time we would use a 15 is for TT and that is using small cart tires where we will run 15/27 gearing and running at much faster speeds than MX. Power is also when you have these motor in the upper rpm's like stated earlier.

riding4fun
05-02-2011, 06:15 AM
Since your air screw is 2 1/2 out I would go down to a 42 pilot jet. Thats what I did when I had the same problen and made a noticible difference