300 Big Bore installed on DRZ 250
Posted 04 August 2008 - 09:51 PM
I've *nearly* finished sorting my jetting out (after alot of waiting for jets to turn up in the post and a few rides with a terribly tuned bike)
02 drz 250
300cc wiseco 11.5:1 and LA sleeve
removed snorkel and opened up air box
ground down header welds
opened up tail pipe on stock exhaust.
TM33p carb upgrade.
So with the above set up the jetting i am running is a 30 PJ, but i am waiting for the next 2 sizes smaller to arrive in mail so i can get a bit better off-idle responce. (yes thats right with a bigbore kit your pilot has to go ALOT smaller) I have just gone up to a 132.5MJ and riding on street today seemed quite good, but i will do a WOT check on way home from work today to see if i should go richer.
but for anyone else doing it these are good ball park figures or maybe do as i am about to do and go PJ 27.5 and MJ 135
Oh yeah the power is f%^&n brilliant!!!!!!!! I'm concidering going taller with my gearing because it pulls so well from idle.
Posted 06 August 2008 - 11:16 AM
ALWAYS when you go leaner with the jetting check plug after a decent run just to be sure you are not running too lean!! Also try going back one richer until you note a drop off in performance.
Posted 24 August 2009 - 12:22 PM
The carb swapped over very nicely. I did have to wiggle it a bit to get it in the boots, but it went in without drama. The throttle cables were too tight, as has been mentioned in this thread. I just Dremeled off a bit of the bracket, as it is solid and beefy; with that done, the pull and return cables fit fine and work fine.
I left the PJ with what was in there (I didn't note it, but it idles dandily); I put in the 132.5 MJ proactively, as I had seen this post, but it surges rather a lot at mid-throttle.
There's a fellow here in NorCal who does carb tuning and did miracles for my CRF150R race bike; I might just throw this puppy at him, as that's a pumper as well.
Posted 28 June 2012 - 11:32 PM