CT 1600 coughing, popping and picking up slowly

[Mona]

Hi all,

My CT 1.6 air cooled has started to hesitate and pop at lower revs, coughs a bit then picks up slowly. Especially going into 2nd or 3rd. It is idling well. 

We've changed the plugs, HT leads, coil, dizzy arm and cap, fuel pump, renewed vacuum pipes, and it recently had a new tank and all fuel lines changed. It initially ran much better, but after a couple of weeks the hesitation and power loss started. After a short journey yesterday, three new plugs were sooty and one was completely clean. The dizzy has two vacuum tubes, one has a vacuum and the other doesn't (when taken off the dizzy end). The carb is a PICT 34 4. The return pipe to the fuel tank had been blanked off before I bought the van (1.6 replaced a 2.0 and the return was not connected to the tank) which we connected it when the tank was replaced.

We looked at the timing, but don't have a timing scale, and wondered which one I should get?





If anyone has any suggestions as to what we can look at next I would be grateful. I'm trying to avoid having to send the carb for a rebuild at the moment.

Thanks

Pete

 

[TONYT25T25]

Has this coincided with the introduction of E10 fuel, also fuel and air filter etc.  Many comments on here ref adjusting timing with regards to using E10 Fuel.

[Mona]

Yes it has. I've been mostly using E5 but think I've used E10 a couple of times.

Will check the comments you mentioned regarding the timing.

Thanks

[sarran1955]

Hello,

Here are your timing marks: Cage and turbine.


I take it you are running the original ignition system, but by your post, the 2nd vacuum pipe is disconnected from the dizzy.

There is not much to go wrong with the Pict 34/4 carburettor. Check all pipes and flexibles, including the vacuum take off  on the rhs inlet manifold, also the vacuum take off on the lhs for the servo assist.

I would suggest you upgrade to a Powerspark distributor and coil, here is a little video to show how:






This is using a SVDA capsule, because I have reduced the system to a minimum, you wlll want a 2 spigot version. Get the coil that goes with it.

I have supplied many of these from Simon BBC on that well known auction site.

As for the timing in general, use a Tippex or similar pen to mark the notches. Since I have run this carb/dizzy set up for years, the petrol has changed, so that on B7 (98 RON no ethanol) I ran at 8* BTDC, then when E10 came along I advanced to 10*BTDC.

If you are really stuck and can wait my return to France at the end of the month, I have several Pict 34/4 carbs, set up and ready to go
and I have set up the carb and dizzy on my workshop engine to post to the UK...

Cordialement,

Air-Cooled Bliss....












 

[Mona]

Thanks, we've sent the carb off now - it was full of grit and dirt.

There was a slight issue as the choke diaphragm appeared to be from a later carb model, pict 5, 6 or 7, as it is square rather than triangular, so had to get an extra kit for that as well. It does say Pict 4 on the carb itself.

[Mona]

Hi again,

I've ordered a powerspark distributor and have been watching your video.

Where did you get the D profile ring from?

Also, if swapping from a dual to single vac, which vac pipes are no longer needed?

Thanks
Pete

[sarran1955]

Hello,

Glad to see you are making progress....

Is the distributor you have ordered a SVDA  1spigot or  DVDA 2 spigots  ??

If DVDA then replace like with like. Use new hose (5.5mm IIRC). Time to about 5* ATDC

As part of another project, I have some 34/4 and 34/5 carbs on the workbench.

I will try to photo these so you can see where you have to blank for SVDA, timed at 10* BTDC

Don't forget to get the coil with the dizzy.. the 'D' ring I get from SK, so should be available in the UK. If not, let me know and I can send one in the post.

https://www.serial-kombi.com/en-GB/spli ... eal-n32644

Hope this helps...

Air-Cooled bliss....
 

[Mona]

Thanks again,

I got the SVDA version with a 3 ohm coil. I hope that is the right one, I didn't see any references to spigots when I ordered it. 

[Mona]

I understand what you were referring to now! The vav tubes on the dizzy.

[Mona]

The part is €0.95 but shipping €14 from SK, will have to find a UK supplier

E D I T. JK have them

[Mona]

This photo shows the engine as it is, I have circled the vac pipes to blank for SVDA, or parts to remove.

Does this look correct?

 

[sarran1955]

Hello,

So if we go from left to right..

Nr 1: idle control...remove
Nr 2: amplifier.......remove
Nr 3: cold start enricher....blank off
Nrs 4, 5 and 6 blank off
Nr 7 remove and blank off ( I used rivets)

You can also remove the throttle damper.

Your crankcase breather tube is kinked..

You will probably have to fit the coil on the tinware as the leads from the distributor are rather short.

Does your thermostat and wongly flap mechanism work??

Cordialement,

[Mona]

Thanks again. 

I noticed the kink in the breather tube but can't find the part to buy. Can something generic be cut to size? 

Cheers 

Pete

[sarran1955]

Hello,

Thanks again. 

I noticed the kink in the breather tube but can't find the part to buy. Can something generic be cut to size? 

Cheers 

Pete

Yes, Cut the tube in 2 and insert a piece of per plastic tube to stiffen. The tube is cut in 2 to make removal easier.
Cordialement,

 

[Mona]

Does your thermostat and wongly flap mechanism work??

Cordialement,

I'm not sure what and where these are?