help bad flat spot

i need to make it to sawtell
and my bug is running bad
1600 tp sbug
timming is spot on 7.5
dwell is 50.4
valves are 6 tho
new plugs
new points
new coil
new filter
pulled the carby downand cleanded it out was good
i think it's carby tuning or heat riser for carby
as it is very cold at the base
it idles not bad the dies then if you power it
it comes good
please help
and hints on tuning the 34 pict or has anyone had probs with the heat riser
thanks everyone

come on craig help me 🙂

we have the exact same problem with ours
also think it could be heat risers as ours doesnt have them(been cut off) and it seems to run better on hotter days.

vacumn adavance on dizzy working?

You shouldn't "need" the heat riser in warmer conditions? We had a 1640 with NO heat riser (blocked off) & standard 34 PICT-4 carb, & it ran fine, tho' it took a while to warm up when weather very cold.

Is the accel. pump working -- or blocked/broken? Easy to check.
Is the fuel pump pumping consistently? Had a failing pump a while back which caused intermittent stopping/stalling. Had been checked by RAC, & thought "OK" though it wasn't! This may be hard to check unless filter is after pump (not a good spot).
Is vac & mech advance working? Failed vac diaphram? Vacuum leaks?
You may be able to set about 10deg initial advance instead of 7.5

Had another standard 1600 that ran OK then suddenly played up at & just off idle -- suspected Carb probs -- pulled apart & cleaned = all looked Good but still wouldn't run/idle. Garage "couldn't do anything". In desperation pulled out idle jet, idle mixture screw, idle speed screw in turn (not at the same time!) & any other bits; got engine started & squirted Carb cleaner, via a tiny pipe that comes with the can, into those holes while revving. Filled driveway with smoke. Problem gone for good! There must have been a blockage that just couldn't be raeched by 'normal' means.

thanks dudes
vac on the dizzy is working
acc pump work
not sure about the fuel pump what the best way to test
and it's cold here about 12 today
and about -5 over night
was -11 over night a few weeks back
i might try to get another fuel pump??

OK at -11C you "could" have problems with poor heat risers :P

Does your left hand heat riser get warm?

Have you read the Rod and Dave articles on tuning the 34 Pict.
http://www.vw-resource.com/

make sure youstart tuning at 2.5 turns out

Also for $10 but a can of carb cleaner and check for leaks at EVERY gasget.

You will surprised what leake.

Check manifold boots as well

left heat riser goes a little highter then the right about 3cm more
i have new mani boots all done up tight

hey fixed it 🙂
sweet sweet sweet
sawtell here i come
it's running better then ever
had to change the main jet to a 145
with the new extractors the old jet was just to small
so are the jets size im mm's ie is that 1.45mm?
thanks all

Yes all the jets for Solex are in mm x 100, eg. "X 132.5" = 1.325mm diam. approx. The mains are a different size to the airs and have a bigger head with a line inscribed around it. Some jets have been damaged by drilling or maybe careless cleaning, so the size printed size may be misleading.
145 sounds very big for a standard-type 1600 motor even with extractors. Maybe the old jet was partially blocked.
The biggest I've ever needed was 135 in the warmed up 1640 (and I think it would probably be fine with 132.5). Standard 1600 engines have been happiest with 127.5 (as per manual) or 130.
Is it possible that the change to a much bigger jet is covering up a problem elsewhere? (and what is fuel consumption like?)

If it really is -11 to -5 you should definitely need the heat riser. (Where does it get that cold?)

Have ALWAYS found I've needed over 3 turns out for Idle mixture screw on every 34 PICT-4 (various ones from average to very good condition) for good idle & transition off idle.

[ Edited on 15-8-2007 by ACE_76 ]

back when i had a 1600 with a standard carb and 4into1 header with a straight thro turbo muffler i got my best performance and fuel economy from a 140 main and 55idle
i had removed my inlet manifold and got the preheater pipe spotless inside and had no real icing problems even with extractors
i was averaging 12km/L on the highway
my bug doesnt do much city driving
but yes i agree a 145 does sound a bit large

-Joel

Well I got really desperate to try and get rid of my flat spot by getting some heat in the manifold in my Manx. Here is what I have now, the last photo is my previous setup on my old exhaust. Muffler for the heatriser is from a lawnmower.

yeah it was -11 here over night
but it's getting warmer now about 15 in the day atm
i got the jets last year at valla for peter richards
and i told him what i had stock 1600 and way going to put on extractors which he said you use a 145 or with out the extractor would be a 140 main

geez brent thats quite a setup u made there thumbs up for ingenuity
the only other alternative ive used (other than keeping the preheater unblocked) is an electric heater element on a twin throat weber i had with no heat risers
these arent availble anymore not is aus anyway so im working on trying to manufacture my own
theyll probably be ready just in time for summer

-Joel

I was desperate and desperation breeds ingenuity. I had a new 1600 but it was an absolute pig in cold weather.

it doesn't get cold at mackay 🤓

Not like down south, but enough to upset my motor🙁

Its the pre heat tube if its blocked you have to replace it twin or single ???

Also the accelerator pump in the 34 pic is shit now matter what u do its unfixiable

Uralla to Sawtell FARK u could push it there and still beat all of us