azzurro

Mine dont quite go that lean (22 = no gas?) , but there is a definite stumble and AFR peak on some low throttle transitions How did you solve it? Reading my new books suggest a range of potential causes/solutions: - idle jets to small, (45 fitted - i recon they will be slightly on the side of too big if anything) - idle mix too lean (AFRs say 12ish at idle, yet to plug chop to see what they say, and all the books say 'give the engine what it wants' to idle best ) - throttle plate position relative to 1st progression hole at idle incorrect The last two only require a screwdriver and time, the first one requires $ and new jets, and i dont think 45s are too small on a very mild 1600.

I will count them soon, they are all in the 1.5 to 3 turn range, idle AFRs are in the 12-13 range with small adjustments either way was making a big difference. I will richen it up a bit no longer an issue after remove, trim and refit 'is it possible it might be messing with me' he asks! "possible"? POSSIBLE!!!!111!!1 (shakes head walking away, throws arms up dramatically)

For Future reference: Weber 40 DCOE 151 on Fiat 1585cc twin cam: Main Jet 125 Main ET F9 Main Air 190 Idle Jet 45 F9 Accell Pump Jet 45 Chokes 32 Venturi 4.5

these ones had equal length shafts so i left them where they were and trimmed them Good Question! Mainly cause I used up my car time and had to do something else. Next day i did go for a hoon, went ok (better than the single carb!), but rich and lean spots and hanging on idle, etc, carbs not going back to idle in balance, etc So, I pulled off the carbs tweaked/ground back the linkage a bit more (master and slave levers were interfering with each other a bit), drilled the carbs mounting holes to 9mm (from 8.5) for that little extra bit of slack, reset the float levels, (12mm for these newer ones with a 26mm droop vs 8.5 and 15mm for the older style) pulled all the jets and gave them a clean out - two main jet stacks were not fully seated, and one accelerator pump jet was blocked ground some of the dizzy scoop on the manifold some more (while i could feel how thick the wall was with the carbs off) installed carbs and rebalanced/set idles etc hooned Great success, but does have a lean point off idle (progression holes?) and is a bit rich elsewhere esp on WoT, thinking of upping the mains to the 135 i have (up from 125) but also increasing the air corrector to reduce the richness at higher rpm (190 currently, no spares), but that is for later. Engine runs and pulls much better than with the single already, sounds great on song and has a pleasing burble at idle, and near silent on cruise with an instant response to stabs of the jandle. reccomended

Rerouted the fuel line to how i planned it, with the fuel pressure gauge between the two carbs In a timely event, these turned up from @ul9601 and so after reading the relevant section i tuned my MAN-O-METER to 11 and made this very very boring and poorly shot video, which is pretty much the 2nd start after getting it to fire and idle and me tuning it by how tall the rod is on my MAN Engines really tappy! ill redo the shims soon. Next day i tuned it a bit more, 1. balancing the barrels on each carb to each other using the air bleed screws (bleed the highest reading to match the lowest) and idle (small adjsutments), then 2. then balancing the carbs to each other (bleed the highest to the lowest side), then 3. adjusting the idle mix (leanest smooth idle, turn 1/2 turn one way at a time until it slows, then back the other way until speed drops then keep halving the difference until you find the spot 1/4 turn above the lean speed drop point) and back around to step 1 again, etc Turned out the timing was pretty retarded too, but also found a better dizzy spot. Had a dig though the filters stash to see what would work. The big factory thing is the Strada Abarth manifold (fwd) and the blue line is wehre i would need to cut it Tuned out only the worlds greatest filter will fit. Even then the (K&N) bases needed a tweak to fit (My 125 Belina has socks over trumpets) RACE MODE (now i see it in the photo, I dont like the look of those trumpet retaining bolts just waiting to wiggle out and fall into the carb. NO SIR) However, small children and animals no longer in danger of ingestion. Check the clearance to the shock tower. Be a real faff to make the Strada filter thing fit unfortunately, would need a custom airbox and a cut and shut, but would also be better than the Ramflows Test drive soon

Stage 7 - gosh! getting it going i would start with the basic factory settings (8-10deg seems about right) and adjust (via dyno?) from there - high power engines are generally set up based on the maximum all in timing (just back from pinking) with idle timing adjusted, if required, to suit However you want it to just run first if its cranking not firing you might have the timing 180 deg out - but start with the basics - got spark Y/N? - got fuel Y/N? - Got air Y/N? if yes to all the above, then check its at 10^deg (static) and once running, tweak from there

i suspect your are 100% correct, but i dont have or have ever seen carbs with that style throttle shaft , and it would complicate both the linkage requirements (two separate pull points) and carb balancing significantly. What is even more silly is that if both barrel pairs were angled the same as (or more, for better dizzy clearance) as the front pair, they would fit perfectly, and there almost no space restrictions towards the firewall that justifies the choices they made. These were NZ designed and made specifically to fit sideys to the dealer developed 125T , with the advantage over the factory LHD models in that the carbs dont compete for space with the steering shaft and brake master/booster (all LHD RWD twin cams had twin downdrafts, or single carbs), so it seems weird to design it in such a way as to require special unicorn model carbs (both dellortos and webers were fitted), and to invite ignition timing/shorting issues eg if i was designing some to be made i would have designed them like this "\\\\"* instead of like this ")\||" *which is ironically pretty reminiscent of the /F/I/A/T/ corporate logo at the time

Finally went and got ol mate @EURON8 to ally weld the holes in the already hacked up side draft manifold so i could space the carbs apart about 4mm from where they were but without fouling on the dizzy or loosing room to seal or flow. some careful 'linishing' later Without any trimming the inner barrells will be 49mm apart, manifold spacing is 40mm, min i can get away with on the carbs is 45mm, max on the manifold is 44mm. its pretty flippin tight and doesnt add up... shaft need trimming by 3 to 4mm and the nuts thinned down a bit as well - i ended up spinning about 3 out of the vice, so i need some more M7 nuts to fit back on the venturi retainers i stole my spares from! no need for retaining washers :/ You can also see how offset the carbs are to the manifold Redrilled and tapped - had to open a old NOS packet to get a 5/16 NSP tap out that had been floating around in my grandads too box for who knows how long before that Fitting the o ring holders show where the manifold needs a smidge of smoothing, about 15 seconds with the belt file. The outer edge of the o-ring diameter is just inside the edge of the manifold face. linkage mod, toyota corolla cable from the old single carb set up to twin weber linkage, all this is sandwiched between the carbs boom AS mentioned in a previous post, these carbs came from a very hot mini, and apart from the drilled and soldered main jets, they all looked very close to what various books and setting tables suggest would be ok for 1500-1700cc engines. 32mm chokes, F9 tubes, 45 idles, 185 airs and random sized but soldered and redrilled mains I had previously ordered 125,and 135 mains so popped in the 125 to start with. old manifold off. Removed the (pretty new) old leaky mechanical fuel pump for good, and installed a factory engine blanking plate. Dumb photo cause it shows the old pump. installed and with new linkage mount and brake vacuum routing, both way better than before. Fuel hose routing will eventually be jiggled to look better (i had orignially wanted to have fule coming in from the firewalll side, but the double ended banjo is a bit long to have the hose make the remaining curve without a kink or rubbing. May try bending it a bit, or maybe just buy a bent one. Clearance is ok, but I cant install the bell mouth into cylinder 3, nor will the air filters i have fit - i will look into making an airbox - i have a Strada 125TC airbox with 'ABARTH' and a scorpion stamped on it that i really really want to make work some how but whatever, lets worry about that after! plugged the fuel in, then spend an age jiggled the timing around and carefully power filing the manifold, then trying to find the best combo of a limited ability to clock the dizzy (it fits in only two more or less fixed positions, maybe 5 degrees rotation?) and dizzy drive tooth alignment , and then it fired up and idled. and revved. Sounds good, and AFRs are ball park YAY! DOORTS!

Probably depends where you are. I use north shore metals in rosedale. They have offcuts and etc of bar stock but dont cut sheet steel on site. The ususly have some half sheets tho. I think a full sheet (1200x2400) of ~1mm zintec was $45 or so last time i got one.

Stupid back shit man, I compressed my spine about 10 years ago (hit the bottom surfing) and it gives me the gyp if I push too hard doing stuff that tweaks it etc (like surfing, sitting, lying down, standing up, excersize, doing garage stuff etc), but its manageable. Worst part is it makes me cranky, not just because its sore and achy but because doing stuff i like to do makes it sore. That xray looks bung, and as your medical professional I recommend doing a cut and shut from the parts body. Get well soon big guy

So, so good. Well done man

What a mission, and in a field find city car too. Top FIATing! Or is it a Zavasta or FSO?

Back firing is indicative of a lean condition. But also too much advance. And your sure that new cam is lined up right? Does it run with some throttle at all? Or on the easy start or a squirt of gas in the manifold?

keen, have an older car that works and needs a drive, and a hankering for aoili with my hot buns on a steamy summers eve

I love it, i was actually looking for one of these, but prices were a bit steep (for me) so i ended up with my blue 125, and it was all downhill from there i guess.