34 Pict 3 Carb Tuning

I Folks

I have seen many posts regards carbs, advice on rebuild& jetting

Have just completed this myself and having trouble setting it up.

Carb is 34 Pict 3

Stripped, fully cleaned in ultrasonic bath.
Ne 130 main Jet
New 55 Idle Jet
New Main Spray Jet
Cleaned up the bypass screw all the other jets replaced all diaphragms, needle valve, New volume control valve. and replaced the throttle spindle bushes with new. New fuel shut off valve.

Followed instructions of Rob & Dave regards tuning the only think haven't done is set the tappets.

Timing set to 7.5 btdc
Using a draper clip in tacho to try and get the setting right.

When I try and adjust the Volume control screw seems to be out too far and the bypass seems to have to almost shut off to get the revs down.

Do the tappets make that much difference?
When setting starting at 850 rpm what should it peak at when adjusting, before reducing tick over again?

I got to around 1300 revs and then backed off a bit

Have not touched the fuel adjusting segment at all and it is set in the middle.

When I put my foot down it hesitates big time.

I have also cleaned the dissy and it is fitted with ingnitor, engine is AD 1600 twin port.

 

Sounds like it`s flooding . Did you set the accelerator pump to where it was prior to rebuild - assuming it ran ok before ??

 

Didn't move the linkage at all went back just the same as it did before.

It ran Ok before but always had a big bit of hesitation when trying to put foot down, especially when pulling away from a junction had to feather the accelerator to get away.

I also haven't seen much info in the way to adjust the pump

 

id do your tappets , set everything else up right , ie points gap , plugs , timing warm it up then set carb as per rob n dave , dont put to much onus on tick over ,better to have it a bit rich too .

 

Adjustment is on a quadrant , with a locknut , on the right . you don`t really adjust the pump - it`s the mechanism that adjusts to give a longer/shorter stroke .
Just seen your post trying to id the distributor - if that`s a 009 (no vac) it`s probably the cause of your problems . I can speak from experience as i plodded on for 20 years with a 009 and `sort of ` got it sorted out but then fitted a £60 SVDA ebay special last year which instantly transformed the pickup and smoothed it all out ...

 

Did you set the position of the throttle butterfly ?

 

Yes set the butterfly, its a bit fiddly, 003 feeler gauge + half a turn

 

Did you examine the barrel to see it the plate has worn a groove it it?

 

not that I had notice but is possible photo before cleaning would that make a big difference, I assume I could polis it out if there is, carb out to examine

 

I did have one that was worn here over-exposing exposing the vacuum hole for the distributor advance which made both the timing and carb impossible to set up.

 

Well, checked valve clearance, timing, set the mixture, ignoring the fact that I seem to have turned screw out a lot further than expected. Next needed to set up the accelarator pump, tried manually adjusting got nothing, so took the top off to measure the amount sprayed, as per suggestions, only to find it is not spraying at all, despite the fact it's a new diaphragm. Guess there must be something stuck. So carbs off again, just as well I ordered another gasket set.

 

One day you will get to be cynical and put back any gasket that hasnt actually fallen apart. Especially if it is brand new and has not stuck to anything properly yet.

 

Anybody any idea is there a non return on this circuit, I am wondering if it got stuck when, it was ultra sonic cleaned

 

have you got an alternator ? if you have you may find your accelorator pump linkage is catching on it ? some put spacer gaskets in to raise carb up a tad to clear it ?? worth checking ?

 

No Alternator looks like the tubes blocked on the accelarator circuit, game managed to free the ball in the non return at the bottom of the chamber but am having problems with the line to the spray jet

 

You can pull out the spray jet.

 

Yes have removed the spray jet, and blown through again, I can now hear the ball that works as non return between diaphragm chamber and the float chamber, so hopefully got that one sorted, and am now getting some air through between the diaphragm and the spray jet location, will run up the compressor again and bang it through, canned air is a probably a bit low pressure to get it all clear.