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Running like sh*t after a needle change

Posted: Fri May 02, 2014 2:42 pm
by iDemonix
Hi all,

Here's the facts:
- I've swapped the original needles for RO needles.
- Originals were:
- Front Right: 115 J51B
- Front Left: 115 J51B
- Rear Right: 118 J51A
- Rear Left: 115 J51A
- All emulsions/pilots in the correct holes
- New float gaskets
- Have *not* done the 2.5mm hole in the slides
- Have balanced the carbs, one of them was really out
- Pilot screw is 2.75 turns, it was quite different to that before...

Anyway, the bike has never ran perfectly as I've never adjusted the carbs. Completed this mini-rebuild and she's running worse. The revs are hanging, but after spraying some carb cleaner about I've found one of the front rubbers has a very slight air leak as the revs rise for a few seconds. Took fooking ages to get her to start this morning, several bump starts got her going, but since the mods, after she's got slightly warm, she cuts out! Here's a video of the issue:



https://www.youtube.com/watch?v=OaVQ7lZDUyo

Bit of a petrol smell about (but they always do), can't decide if it's more than usual. I know there's a slight air leak that I'll fix on Monday if I get time, but I thought an air leak would make the revs high, not cut out? So I'm thinking the air leak is responsible for the erratic revs, but not sure why the cut out - possibly running too rich? I put a sheet of paper at the can and revved her (free flowing full tyga system with a maggot can for now), after a while the paper was a bit moist with what looked like dirty black water or soot.

I'm going to whip the tank off on Monday, hopefully I don't need new rubbers and it's just a case of re-seating, but I'm not sure how to lean out the mixture with the carbs in place.

Re: Running like sh*t after a needle change

Posted: Fri May 02, 2014 2:44 pm
by iDemonix
Oh and yes, I've played about with choke and idle for ages trying to get her settled but this stalling seems to happen every time...

Re: Running like sh*t after a needle change

Posted: Fri May 02, 2014 4:21 pm
by Neosophist
pilots out a lot, only 2 turns is ok

Re: Running like sh*t after a needle change

Posted: Sat May 03, 2014 11:29 am
by iDemonix
So turn them all the way in then back out 2 turns? Are they accessible in place on the bike? Although I suppose they need re-seating anyway...

Re: Running like sh*t after a needle change

Posted: Sat May 03, 2014 8:41 pm
by Neosophist
iDemonix wrote:So turn them all the way in then back out 2 turns? Are they accessible in place on the bike? Although I suppose they need re-seating anyway...
yes long screwdriver

Re: Running like sh*t after a needle change

Posted: Sun May 04, 2014 2:27 pm
by royster81
Is it not 2.25 turns out ?

Re: Running like sh*t after a needle change

Posted: Mon May 05, 2014 10:21 am
by Neosophist
royster81 wrote:Is it not 2.25 turns out ?
Depends on your bike, 2 turns is the base setting. upto a 1/4 each way.

Re: Running like sh*t after a needle change

Posted: Tue May 06, 2014 8:55 pm
by iDemonix
Thanks for the help guys, no idea where I got 2.75 from but it's what I wrote down.

Backed them all in half a turn to make it 2.25 and she's running 10x better and starting instantly. There's still a slight air leak causing the revs to hang a bit, but I'm sick of taking the tank/carbs on and off so it can just stay until the next time I'm doing work (probably soon!).

Just the rear brake and then it's MOT time hopefully!