Upgrades

[JONATHANSANDERS]

I recently upgraded our stock 2010 drr 50. I eliminated the oil injection bike ran fine. Installed a new top end( polini)and a koso pipe . The squish is at .6mm and the compression is 140 psi. The needle is the stk 68 pilot is 38 and the main is 112. The spark plug is a ngk Br8es. This thing will not run smooth it seems like about 1/2 throttle it is sputtering like crazy and full throttle it has a heavy bog. I changed the main in small increments from 105 up to 125 with no change. Please help I am desperate and not sure what to do next and the rider is getting mad.Thanks for any help.

[fomospede]

crack open the cvt and replace the torsion and clutch shoe springs
adjust the clutch springs to a stall of 6k at a minimum
this is just a starting point and needs to be set to your engines working rpm range

[jerkyboy]

What size carb? what is the position of the clip on the needle?
What weight rollers are you running?

[JONATHANSANDERS]

Stock 21 carb and the needle is 4th from the top. The rollers are 2.75. This issue even shows on the stand. I really don't think it's a clutch issue. I am running a green heblo spring red clutch springs and a 782 belt.

[fomospede]

hook a tach up and prove me wrong and go from there
its easy and will rule out the clutch
those rollers are little light maybe your not shifting either
id check belt travel by marking the variator with a line id to od and run it it should move right almost to the top

a tach is a must have item

if you want any hair left after tuning that 50!

[JONATHANSANDERS]

The belt doesn't get to the top of the variator. It seems like the motor doesn't get that high of rpms.

[fomospede]

make sure variator moves freely
i use graphite on shaft it slides on being dry or using oil is inconsistent

if all free move up on roller weights

but once again you need a tach

trust me ive wasted hrs only to come down to the cvt area
low stall
blued bell, out of round bell
weak springs

does it rev clean with no cvt ?

[RCR_531]

Do you have the unlimited RPM cdi box (small one) or do you have the one with the two bolts that you can jump? (longer one)

[jerkyboy]

Could be hitting the rev limitter. Stock ones only let it turn 11,000
Like said above you need a tack.

[JONATHANSANDERS]

I have the unlimited one with no screws. I have two and tried both with no change.

[fomospede]

we live pretty close im in rockford il. if you need a hand

[redonkulousruntsracing]

The 1/2 throttle bog sounds like the needle clip position and I would try leaning out the main to address the top end bog. Are you blowing out blue smoke? Rollers do seem light but I would leave them in there until you get the carb right, with them being that light you probably wont get full belt travel. 3.5's are a good starting point. Even properly adjusted you still may have 1/8 - 1/4" of mark showing. You said you unhooked the oil injection, are you running 40:1 premix with a good oil?

[selbygirl]

check all your wireing and grounds .. i have had problems with the factor conections.. the wires going to the coil and cdi box i allways hard wired them my self ... or just clean them and make shore ther tight ,, if you can swing it get a pvl ,,, and i had a shoe spring go bad it felt like carb problems .. and if you still have the stock kill switch upgrade to a better one check your spark plug wire on the spark plug i zip tie them together sometimes they shake loose.. end if it is bogging at top end try a smaller main jet... but keep an eye on your spark plug color.. and all our bikes we run 100 octain 32;1 , when ever i run pump gas they run like poo,, take some carb cleaner and spray around intake to see if your sucking air when its running , if the the rpms rise or lowers then its leaking

[JONATHANSANDERS]

Not 100% , but I think we've got it nailed down to the bike is hitting the rev limiter . I guess the next purchase is a PVL. I did have a slight air leak and that would explain the unresponsive bog at the mid range. I really appreciate everybody's suggestions with this issue. I was getting real frustrated. Thanks again