Cheers GTorph, This is very much the conversation i had with you over the phone about 2 months ago. The problem is making sense of your wisdom and working it out myself. What you're saying is that the GT is negative earthed. Which means the neg wire from the coil should go to the dizzy and the positive wire runs back under the dash to the key.
If this is the case, then i have those two around the wrong way !?!

And thanks Izzie. When I put the reconned dizzy in the same way it came out and attached the leads the same way it wouldn't even start !!
Then i put the leads on 180 degrees and it fired.

Could have been truly blonde in a former existance !! Not going to test anything tonight. Too late, just got home from debogging some weirdo deep in the pines in the dark.....that was an interesting excersise.

B.

Yeah, that's a mongrel when you get faulty new bits, but it happens. (Had a new globe in the Sube that lasted 1 day last week - Narva!)
I agree with all Greg said, EXCEPT black with red trace is negative, on sedans at least.
No question is Dumbass mate, no one knows it all! I think of the points as a switch for the primary circuit of the coil. When the ignition is on, current is supplied to the + side of the coil, runs through the winding, out the - side, through the closed points to ground. This creates an energy field within the secondary (High Tension) circuit of the coil. When the points open, the primary circuit is cut and the field colapses, sending a 36,000 volt spark down to a plug.
This happens 33 times per second @ 1,000rpm in a 4 cyl motor. This is where the gap width (and Dwell angle) matters. The points need to be closed long enough for the field to build up, and open long enough to let the spark escape. It becomes more important as revs rise.

AND I've made the same mistake (reversed leads), and not so long ago!
Hope were helping,
Cheers, Matt.

GT2, you spoke on your first post of backfiring and carrying on out of one of the carbies.
could your problem not be electrical but fuel or carbie related?

i know it can be difficult to isolate but worth a thought


OZ

Thanks everyone for staying with me on this problem 'cause it hasn't gone away yet. The info is all good and I'm starting to make some sense of my limited knowledge. So please keep the info coming if you have any ideas.

Tried a few things last night, and think i've eliminated some potential issues.

Pulled the tacco wire off the coil ( neg. side ) and still firing like a pig. Also took off the wire from coil to dizzy and replaced with home made test wire with spades on both ends. Again ran no differently.

Then took off air cleaners and reved engine by hand. Also deliberately half stalled the engine by covering carbie hole with palm, and then revving it up afterwards. Carbies sound like they are getting fuel ok but when it back fires through the carbs under revs, it does this through both together. This possibly happens because of the build up of unburnt fuel due to the lack of ignition intermittently during rotations. Less likley to be fuel / carbies.

So here's the theory. It could be some sort of elecronic miss or short or arching. I say this because when I put a timing light on each spark lead it blanks out intermittently when I raise the revs.

The other possibility is I haven't set the new dizzy up correctly. Will phone the dude who rebuilt it tomorrow. He said he had many years experience setting up and tuning race motors and would be happy to have a look.

After that it'll be a mobile auto electrician, who can be patient enough to look at the mess of old wiring and attempt to find the short if there is one.

Cheers for the support again people. When it's going again there will be cause for a mass Bellett party !!

B.

GT Too,
These things can at times to be the simplest issue, make sure your fuel filter is clean also!
We all tend to look for the most difficult problem, in place of starting with the most simple, keep on it you will resolve it eventually, soon hopefully!!!!
Dave M.

For what it's worth B i would disconnect the linkages to the carby's and crack one open and when it comes back to idle crack the other one ? it should rev on each carb. Then maybe a compression test might give you some answers.

for all the info you have been telling us, the ignition is breaking down under load.
as the wiring system of the Bellett is very simple, and you seem to have covered most everything i can think of, then its coming down to a new part thats faulty or not suited.
What type of coil is being used? is the distro cap centre pin spring moving enough to contact the rotor center?
if you remove cap and rotor and dis connect Vac advance from carbi end and suck it (hard) can you see the distro base plate move? what brand and designation spark plugs are you running
has there been any change at all through the whole process and if so, where and what did it?

OZ

Hello again.
Now you can say "DURRR" to me if you like, but it's occured to me that the last time I saw carbie backfiring the cause was wrong firing order. The dizzy shaft turns ANTI-CLOCKWISE , but he had them arranged clockwise. This makes the 1-3-4-2 become 1-2-4-3. So. 1&4 hit in the right place, but 2&3 fire with the intake valve open.

Yeah I know, basic stuff, but I had to add it just in case.
Hope it's all smooth real soon!
Cheere, Matt.

That's ok Farmer, no "DURRR's" from me. Just keep the suggestions coming. I've had the leads off so many times in the last few month's I reckon could put leads on correctly blindfolded, hahah.

having said that, I ran some more tests yesterday just to eliminate possible faulty new or old parts. Swapped new dizz cap for old dizz cap. New rotor for old rotor and compared. Changed new leads for old and in every possibly mix and match to eliminate leads.

And yes Oz, good observation, the centre prong on the new dizz cap is about 1/2 cm shorter than the old one and looks different too. But this also made no difference to the running as I think it still touches the top of the rotor.

All the above variations made no difference. Today I"ll run a test wire directly from the + on the coil to the + on battery when it's running and then disconnect the + lead on coil to bypass the ignition. This is more or less what GToroh is suggesting though I have crude or no testing equipment.

My good mechanic from down the road is also coming to visit today (like a doctors house call) time permitting for him. From most of the info I've told him he is still convinced it's electrical and possibly my set up of the new dizz may be incorrect somehow. Hope fully he can pin point and fix.

B.

I think you shoulkd just give up and I will buy it off you? Not going should be woth $50 or so? Geoff

Wondering when one of yus Bellettians was gonna make me an offer Did I hear 50 K Sorry Geoff, not finished with her yet.

In ya dreams.....and mine as well

Cheers, B.

I thought it was a good offer.
Do hope your mechanic can throw some light on it, very frustrating when they do this to you, trust me I know with Isabitch.

MEGA ANNOUNCEMENT

IT'S ALIVE, IT'S ALIVE

The great "Martin the mehanic" from down the road didn't take too long this morning to put his finger on it. A little amp meter testing and dizzy fiddling showed the new coil I was sold wasn't the correct one. it was supplying too much voltage to the dizzy, touching up the points and consequently breaking down the spark.

Whooohoooooo !! Just come in from setting up timing mixture and idle. Time to thank all for staying with me on this one. The support was just as important for my sanity as was countless good advice. And i may have learnt something........PATIENCE

There should be a prize for the closest correct info. I think you get it Oz, you did ask what sort of coil i've got in there

Time for a test run this arvo.....Yeeeeeeehaaaaaaaa

B.

GT2

I dont mind who was closest, just glad to hear its back on the road



OZ

great to hear the blue beast is back on the road!

Thanks guys. And running well too. A little harsh since sitting in the shed revving the bejeezzas out of it missfiring, for the last few months.
But a good couple of runs should smooth things up. Also idles sweeter that it's ever done, even tow through the revs, and starts easy.

Conclusion : Possibly faulty original coil to begin with. Was told by the shop assistant to buy a GT40R coil and that i would not need to run a resistor off it. WRONG, WRONG, WRONG !! The correct coil is what is in there now, a GT40 (C 80 fuel miser from repco, $37). This has a 12v input and delivers 8 to 9v out the other end to the dizzy.

The bonus was finding some other crucial bits which needed attention, including leaky master break cylinder, and internal workings of dizzy just about had it.

B.

Sounds like she will be ready for the B2B after all.

Got my Blue Deluxe doing the run this year. But alas i will not driving as i have a previous family commitment on that weekend. i think my Daughter will be driving it and i have just had the Carbi fully recon so should be running sweet as.

Not happy about the double booking but what can you do...


OZ

Great news mate!
I Should have thought of that, The Florian has a GT40 coil fitted - no 'R'.
At least everything is new now! Should be good for a long while.
Cheers & enjoy the B2B,
Matt.