Carb setting on 1600 SP

[jimbope]

HI Guys,

Just thought Id run this past you lot and see if any one has any ideas..


Running std solex carb (single adjustment screw) which I reconditioned with new gasket set etc.. when I did engine last year. I aslo decoked the heat risers

Now the bus runs sweet as a nut on the move and It starts on the button. Its just to get her to idle I have the screw that faces you as you look at the engine screwed all the way in flush with the arm. You would expect it to rev its tits off because of this but it doesnt. When its warmed up fully it does idle a bit high - If I back it off it cuts out when driving when the engines cold after the choke has come off.

I`m thinking of buying a new carb - it seems that theres mixed opinions about the new EMPI/BOCAR ones?

I think I will get hold of a good used carb of known quality and try it. If anyone in the camb area has one for sale/loan that would be good.

Does anyone else have their idle screw all the way in? Is this masking a fault elsewhere within the carb?

ANy ideas would be greatly apreciated!!

 

[crede999]

this may help

http://www.vw-resource.com/34pict3.html" onclick="window.open(this.href);return false;

regards
chris

 

[Ands1]

Make sure your accelerator cable is adjusted correctly on the carb,
refer to Haynes manual on how to set it.
Andy

 

[jimbope]

OK, my carb only has one mixture adjusting screw on LH side. This apparently just adjusts mixture at idle - as soon as the carb comes off idle circuit the main jet takes care of fueling.

I will however try adusting the accelerator cable - my pedal is quite close to the floor - i e doesnt seem to have much travel.

It just seems odd - if I set the idle screw against the choke cam as per set instructions the engine just cuts out straight away. The only way to get it to idle is to screw the screw all the way home.

 

[Ands1]

Set the cable first mate.

Disconnect the cable & carb throttle return spring.
Pull the throttle all the way back (screw the idle screw approx 1/3 out) & then push it back up 1 mm.
The accelerator pedal must then be pressed all the way down & held in place (I used a cary battery).
Connect & tighten the cable in place, remove battery from pedal & refit carb spring.
Do all this making sure the idle screw returns onto the lowest step of your throttle thingy :lol:

Warm up engine & set revs (when choke is off) with idle screw
then turn in screw on side until revs drop
then turn the same screw out until the revs pick up again again.

Job done

Andy

 

[Justin & Muttley]

Set the cable first mate.

Disconnect the cable & carb throttle return spring.
Pull the throttle all the way back (screw the idle screw approx 1/3 out) & then push it back up 1 mm.
The accelerator pedal must then be pressed all the way down & held in place (I used a cary battery).
Connect & tighten the cable in place, remove battery from pedal & refit carb spring.
Do all this making sure the idle screw returns onto the lowest step of your throttle thingy :lol:

Warm up engine & set revs (when choke is off) with idle screw
then turn in screw on side until revs drop
then turn the same screw out until the revs pick up again again.

Job done

Andy

Sound advice!

I had similar running problems when I rebuilt the Solex on my '67 bug - the idle control jet solenoid was faulty as it turned out; I replaced it and the carb idled and ran like a dream (you deffo need to set the cable up properly first, though).

Let us know how you get on...

 

[jimbope]

Thats great advice chaps - I usually just pull the cable thru and fix it to the carb!!

I have just put a standard exhaust back on so need to have a fiddle with the carb anyway.

I will try and have a go tomorrow night after work and report back!!

 

[jimbope]

Ok - last night I reset the cable - TBH it didnt end up much different to where it was before.

However the air screw on LH side of carb appeared to be turned right in! After unscrewing it 2.5 turns the revs rose and then i turned it back till they dropped a little.

The idle screw is now not screwed right in anymore but still further than it should be I think.

I have noticed that Timing plays a big part in idling.

Now my puley has a single notch which assume is the 7.5BTC mark and a dent on the front face of the pulley (to the left of the notch which I believe is the TDC mark.)

Now I always set the timing so I get a `click`from the points when the little notch is in line with the crank case join. I the put a strobe on No1 lead and check the timing dynamically. Now this is a stupid question I know but with my gun set to 0 deg which mark do I line up with the crankcase join? If Ik new this for sure then I can set the gun to 30 deg and rev the engine to 3200 and then tweak the dizzy to get the notches in line. Im just not sure whether I should be alligning the TDC or the 7,5 mark.

The engine seems to run sweeter/smoother/faster the more advance i give it at idle - but obviuosly dont want pinking. I have a 009 dizzy.

Any help would be greatly apreciated!!