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hi guys me again,just rebuilt engine rebore 1.25 over ,all gaskets seals bearings and the only way she will run is if i kick her with 1/4 throttle fires up every time but she wont idle choke doesnt make any difference what so ever.i hav pro circuit pipe and everything else is standard including carb, im at sea level temp around 10c and 40/1 mix any ideas i know your going to say clean carb but hav done that once,when she is running she is sweet

Idle speed adjustment does nothing? Can't crank it up far enough to stay running?

What size is your pilot jet?

When you cleaned the carb did you remove the choke knob and blow it out? Also the idle knob takes a shitload of turns to raise the idle, its something like 20 turns from the stop.

pat do you know what the airscrew is? do you know where it is? put it at 2 turns out for starting point- turn idle knob up- see if it idles at all. typically from what ive seen the pilot is rich if it wont idle at all- if pilot is leean it idles eratic, run on, etc

mine would idle w/ a 55 pilot but would weeeze when i let off after a hard run and was a bitch to start.. I tried a 58 was a little better to start but a bear... so im going back to the 60 where it was 2 kicks to start regardless of where or what the conditions were and doesnt idle. Im going to give the mikuni powerjet a shot when i get the funds here this summer and hope it helps cure my problems

as i said all standard air screw 2 turns idle all way out/choke,wont start but will with 1/4 throttle and then wont idle defenitaly pilot circuit problem,plugs are soaked with fuel when i take them out.

go down on pilot jet size

right guys determined to fix this issue as i hav spent lot of money on this bike,spent few hours last night on getting good understanding how carb works,stripped carb again noticed wear on float valve so am changing that and going down couple sizes on pilot,choke has no affect when cold but can get it to work if i use throttle adjustmen to pick up the revs,but feel this is only masking other issues,any of you use throttle adjustment to get them to run right ?

Usint the throttle adjustment to make it idle is the wrong way of doing it.

yep thats exactly what i though ,its just masking another issue i can start her 1/4 throttle easy but as soon as i let of throttle she dies,i hav been told that these carbs were not meant to idle,she will fire when cold with choke on then thats it hav to use throttle and wont idle just dies of throttle

sounds identical to mine... except my plugs werent soaked.. However i did foul one about every 4 trips to the sand dunes..

hav you rectified the problem,getting relly pissed off now.looking at new carb maybe

nope i just deal with the no idle.. i rode it for an entire season that way and was fine with it... It wasnt until i rode with bob and mfdb that made me start fiddling with it then i just gave up adn am goin back to where it was

we get a big fat hookup from sudco on pwk's

I know you said the carb's been cleaned but sounds like the pilot is plugged up.

But what size is the pilot jet?
Weither its a 50 to a 60 it should get some idle out of it.

i hav cleaned this carb so many times every hole is clear,theres no way pilot is blocked,using 55 pilot tried variouse others still wont idle with throttle shut of it just dies

seriously sounds to me like a rich pilot circuit. instead of switching the pilot, first try messing with the air screw. with the bike running and your hand on the throttle, try to get it at as low of a speed as possible without it dieing. then start turning the airscrew while holding the same throttle position. turn the screw a little and try to tell if the engine speed changes. the idea is to have the screw at the postion where the rpms are the fastest, but no further. your target should be around 1 1/2 turns, so, lets just say it goes at the highest rpm at 3 turns out, than go down in pilot size, if it runs best at 1/2 turn, go up in pilot size.
once all that is sorted out, then try turning the knob to get it to idle.

running 43 pilot now still wont idle but runs like a bloody steam train

patgas wrote:running 43 pilot now still wont idle but runs like a bloody steam train

What is a 43 pilot? Is that like a custom job?

Good eye Mojo....

ya, put a stock sized genuine keihin pilot jet in there and start with the air screw as I previously posted.
BTW, how does it run from 0-1/4 throttle?

sorry 42 .runs good at 1/4 throttle with 42 and seem to get revs a lot lower before she dies,tried 55 but had to hav air screw right out to get the idle to pick up,like 3 turns tried 50 was a bit better with 42 throttle hardly open but still hav to start her 1/4 throttle,but she still wont idle.shes a little spluttry low down but not bad.tried the 55 and the air screw was nearly removed to get her to run fast,thats why i started to go down in pilot sizes.any ideas any one would be greateful,same issue as before rebuild,is carb knackered ? spoke to other people with this issue and only way they rectified was by replaceing carb with pwk 39 ,what do you think

carb slide and body are probly worn out

yep thats what i thought.

I wouldn't htrow any more money at that carb.
Get a PWK. Easier to tune, runs better.