Juddery on full throttle

Aki · Post by **Aki** » Fri Apr 28, 2006 9:19 pm

When accelerating hard my L1 gets very juddery from about 7000-10,000 rpm, Over about 10,000 revs its perfect and pulls hard. its completely de-restricted and has a K&N and sports can.

Anyone know why it would judder so bad?

It feels a bit like my old suzuki Rg 125 when the power valve was opening, went rather juddery.

Im a bit baffled!

Thanx, Guys+Gals!!

Post by **masterofinsanity** » Fri Apr 28, 2006 10:07 pm

had it been dynojetted??

Post by **Xphyral** » Fri Apr 28, 2006 10:10 pm

dunno what kind of juddery sensation you mean, but sounds like you got a flatspot from that race can. Re-jet and tune it out and things should be fine, if it is a flat spot it's not causing any harm other than probably a little annoying

Aki · Post by **Aki** » Fri Apr 28, 2006 10:26 pm

it is very annoying and i've only been riding it today!!!! lol!

I dunno if its been dynojetted to be honest, the previous owner was a bit unsure of whats been done to it.

the_avenging_bucket · Post by **the_avenging_bucket** » Sat Apr 29, 2006 9:57 am

i get exactly those symptoms when i forget to replace the 2 blank-off plugs in the top of my airbox, or if i remove the little snorkel/ pipe thingy in the front of the airbox (removed it coz i thought bike would breath better, got nice torque low down but ran crap above 6000 7000 so put it back immediately)

basically the whole induction, exhaust system is very sensitive to changes.

the_avenging_bucket · Sat Apr 29, 2006 10:00 am

also check that you have a proper gasket/ seal between carbs and airbox.
don't jet the bike before you make sure the airbox is properly sealed.

the_avenging_bucket · Sat Apr 29, 2006 10:07 am

read somewhere that the snorkel thingy doesna fit if u have the k&n filter, if that is the case, see if u can borrow a standard filter plus the snorkel thingy, testride with that to identify prob.

Aki · Post by **Aki** » Sat Apr 29, 2006 12:10 pm

Thanx a lot for your help, I've got someone to have a quick look at air box and there apears to be a little gap where it joins too carbs so could be that?

I'll keep my eye on ebay for a new air filter box

the_avenging_bucket · Sat Apr 29, 2006 12:20 pm

yes.
makes a big difference. when i got my bike had same symptoms as yours, cause 1 of the blankoffs were missing as well as was sucking air between carbs and airbox...
i made a gasket out of 5mm foam camping matress material (tested it was fuelproof by leaving in fuel for a few days). i needed to use thick material cause my airbox is slightly warped where it joins the carbs.
after sealing box revved sweetly all the way through... but like i said make sure u have the pipe in the front of the airbox as well, removing that causes same symptoms...
good luck.