I requred pictures of a 1A-c and 2A-c head

[AJRGale]

OST, I got "hotter" ones thinking that it may have been my issue with the sparkies getting to much heat, but going by that 2nd chart, I may have got that wrong.
so colder sparkies can run in hotter combustion, and hotter ones for cooler?

the last lot i took out look closer to oil fouled

hah, always thought the whole lot to be white as lean, since the thread crown is blackened and the Ground Electrode is, well it looks damn white there, I would of called it gray.

ah well, time to take the carby down again, check to see if I have the jets in the right place.

reason why I say that, last time I built the carby, I didn't pay to much attention to what jets I was putting it, im sure I had them laid out in the right order, but I didn't double check, and I think that is my fail there, the mix screw is out passed 5 turns..

Also, ask me stupid question, I'll give you an answer if I can, I don't mind looking like a fool..

And I was going to attempt to move this to General car talk, since this has little to do with Conversions, but I cant see how.

[Dazza]

If the mixture screw is out 5 turns to get it to run then the primary idle jet is too small. Idle mixture screw should be somewhere between 3/4 and 1 1/2 turns out when you have the correct size idle jet. Check that the secondary butterfly is fully closed when the throttle is at idle position. There is an adjustable stopper for the secondary throttle shaft that screws in from underneath. if the secondary butterfly is slightly open you will have trouble getting it to idle smoothly.

[AJRGale]

yeah, the secondary is closed till about 1/3 throttle. If I got the right jets in, but the wrong air jets, that'll lean it out too yes? I'm thinking if I had the secondary jets in the main, they are larger by default, so that will richen the mix, the air jets adds more air to the mix, leaning it out before the emulation tube.. or am i wrong in my understanding on how these work?

[Dazza]

Air jets really only come into play at high revs. Main jets affect mixture under load. My Hilux with a 4Y engine has a bigger main jet in the primary barrel to make it run right. The secondary main jet is a lot smaller. I think this is because the inlet manifold is too small to flow as much air as the carby can. Something is not right with your idle jets if you have the mixture screw 5 turns out. I would try a 45 primary idle jet and 40 secondary idle jet. Not sure what your mains should be. I would just take it for a run and if it surges or backfires through the carby under load it is too lean. If it falls on its nose it is too rich. You need to test it at part throttle to get the primary jet right and then test at full throttle to get the secondary jet right.

[AJRGale]

Well, just popped out the jets:
Primary side:
Fuel Jet:130
Air Corrector:135
Primary Idle:55

Secondary side:
Fuel Jet:135
Air Corrector:175
Secondary Idle:50

So looks like I'll have to find a kit, unless someone has them laying around?

[Dazza]

What emulsion tubes are you using. I would have expected it to be a bit rich with those jets

[AJRGale]

you know what, I could never get them out.

[Dazza]

Emulsion tubes usually jam in there. I screw a small wood screw into them to pull them out. just screw it in enough to get a grip on it but not too tight and give it a bit of a wriggle and the emulsion tube should come out. Also check that your aux venturi's are not loose. I have seen them loose enough to rattle around and suck air instead of sucking the right amount of fuel through the jets. They just lift out from the top once you have the top of the carby off. If they are loose you can tighten them up by jamming a bit of beer can in the end opposite the emulsion tube well. Also the early aux venturi's had a brass sleeve pressed into them that could come loose and spin around so it blocks off the flow of fuel. The opening needs to be at the bottom. Another thing to check is the power valve. It could be blocked if the carby has sat around for a while and corroded. This should only open up when the engine has low vacuum. The jet is not in the power valve in the bottom of the carby. It is in a passage under the power valve that runs back toward the main jets. It is only tiny about .7 of a mm so it can easily be blocked if the carby is dirty. You should be able to spray carby cleaner into the power valve passage and see it come out where the primary main jet screws into.

[AJRGale]

Right'o, I'll see what i have to get em' out. The venturi is almost a pressed fitted, its tight fit but I'll double check it juuust in case.
The power valve, replace last rebuild (about 3 moths ago), checked it was still working when I opened it up to get to the jets. With the last PV, the diaphragm was stretched out that if filled the vacuum chamber, basically useless.

and on that note, im going to pop it open again, and i'll edit this with the tubes numbers.

Both are F66

I have noticed that these carbs have a anti-dieseling valve, mine doesn't it has a port to be dilled out, that isn't hard to do? or do I need to tap it as well?

[Dazza]

When the power valve diaphram leaks your mixture will be extremely rich at idle and part throttle. I would have thought that your engine would be running rich with the jets and emulsion tubes that you are using. I was kind of expecting F50 emulsion tubes with the jets you are running. I think you might have to go back to the proper heat range spark plugs and check the colour again. Its possible that you had a build up of carbon in the combustion chambers from running rich that was causing the pinging and you will need smaller main jets.

[AJRGale]

so you're just as confused as much as me on how strange this thing runs?

Last owner took it to a shop to be rebuilt for the engine size, but about $1000 later, all it looks like is they just replaced the gaskets, and some of the clips were replaced with wire. i went to ask them if they still has the jets they replace it with, they just looked at me stupid.

so, lets round this down:

Carby came off 4A
1A head on 2A: probably not it nothing, to say otherwise
I did mentioned 4A dizzy, possibly not balanced for 2A (the advance curve is for 4A, hence foot off for second to get vacuum again after gear change)
all pinging can be negated with retardation of the dizzy.
Sparkies showing leaning/over heating, Gotta say though, been running new sparkies for about 5000KM
jets show to be on the leaner side
maybe carbon build up casing pinging, gonna get an inspection cam to look into them chambers, I suspect minimal though.

[Dazza]

Yep i am starting to run out of ideas. Have you checked compression to see if it is too high for regular unleaded Has i got an EGR valve that is stuck open or something stupid like that

[AJRGale]

its got the old style pipe cross over, not the pipe to air filter. and yeah, it still works. I have not done a compression test with it, I have no idea were my kit went.