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Juddering

Posted: Tue Jun 12, 2012 10:41 pm
by RX_EJA
wondering if you chaps could help me, the bullit is juddering along at times there is no rythm or rhyme to it althought of course when ive got my foot down its fine, so its mainly when your pottering around setting off slowing down, i stripped the distributor down the couple of weeks ago, and was surprised there was no points some electronic gubbins, anyway cleaned and rubbed the contacts in the dizzy cap and on the rotor arm and wire brushed the plugs, also adjusted the timing (no gun just by adjusting and trying it on the road to see how it felt) also adjusted carb and it seemed fine but its started doing it again! shes pulls and sounds perfect!

ah should also mention noticed something today, when shes idiling the revs sort of fluctuate not massviley but rev counter needle is defo twitching ide say between 750 and just under 1000 rpm its not noticable prob cos of the sound of the exhaust and fan!

My immediate reaction is new distributor, plugs and leads! but wondering if i could be overlooking something???

Re: Juddering

Posted: Tue Jun 12, 2012 10:59 pm
by myatt1972
Before you do anything set the timing with a light.
Hunting is a sign of the mixture being wrong.

Re: Juddering

Posted: Wed Jun 13, 2012 7:21 am
by TOOL
Define "adjusted the carb".

Re: Juddering

Posted: Wed Jun 13, 2012 10:08 am
by RX_EJA
TOOL wrote:Define "adjusted the carb".
set the mixture and then checked it on the emission testing equipment readings where almost zero, idling a lot better!

Re: Juddering

Posted: Wed Jun 13, 2012 1:08 pm
by TOOL
I run quite high HC readings. Zero doesn't sound good.

Re: Juddering

Posted: Wed Jun 13, 2012 1:29 pm
by RX_EJA
oh dear, thanks chaps will have a look at it on the weekend!

Re: Juddering

Posted: Wed Jun 13, 2012 2:49 pm
by MelloYello
Do you mean the drive shaft/axle union joints?? When your foot is of the gas and you are slowing down- it kind of bunny hops along??

Re: Juddering

Posted: Wed Jun 13, 2012 11:46 pm
by RX_EJA
silverarrow wrote:Do you mean the drive shaft/axle union joints?? When your foot is of the gas and you are slowing down- it kind of bunny hops along??
yeh it does kind of bunny hop along but it can do it just as often when i put my foot down, or slowing down either with my foot on the brake or just off the acclerator, but it feels like the engine not the transmision or anything like that! well i hope it isnt as it sounds expensive!

im trying to find my timing light i know i have one somewhere!

Re: Juddering

Posted: Thu Jun 14, 2012 2:23 pm
by mullins
Sounds like what we used to call "pig rooting" back in NZ. Pretty common, especially on ported rotors where you pretty much have to slam it into neutral when coasting.

Re: Juddering

Posted: Thu Jun 14, 2012 3:41 pm
by TOOL
mullins wrote:Sounds like what we used to call "pig rooting" back in NZ. Pretty common, especially on ported rotors where you pretty much have to slam it into neutral when coasting.
Common on IDAs (hence progression hole mod) but a 4 barrel Nikki running primaries and secondaries should be smooth as silk.