QUOTE(porschetub @ Sep 3 2023, 04:51 PM)
Thanks for all the replies and sorry for the delay, I can get them very close but critical to have idle screws even for normal idle and upping engine speed for balancing .
Spent a lot of time dialing the length of the drop links and have replaced many worn out ball cups ,strangely nearly all RH thread ones were worn out ? .
When I first rebuilt these before I fitted the 2.2T motor I noticed both side cam rollers had seized @ some stage and there were area's on the rollers that had flat spotted and there was a lot of wear on the throttle cams which I have since replaced.
Both the carbs were in very poor condition,I had no history when I bought this engine but the seller on behalf of the owner did say that "it ran like shit" this turned out to be a blessing as I knocked the price down and it turned out just to be the carbs and I had bought a strong engine.
Working on more carb repairs as our crap fuel has buggered several parts just waiting to hear back from alfa 1750 on ebay,will update ,cheers.
Click to view attachmentI usually increase the idle to 1200rpm or so for tuning, as it smooths out the pulsing of the readout. I have the overrun correction circuit disabled, as I suspect most do. As you point out, once achieved, the balance is pretty consistent across a range of RPM (which is of course the goal!)
The accel pump cam rollers on my TIN40s (when I got them) had their bearings crumbling; so they would have flat spotted if I'd used them as is. Getting replacements seemed impossible at the time, so I modified some from McMaster-Carr ones to fit, which was tedious. If Alfa1750 has these available that would be good to know for sure.
My carbs have been gone through recently - twice - as I foolishly let them stand over winter without flushing or draining them; and the the Ethanol based fuel wreaked havoc on the entire fuel system! Weeks later: new stainless fuel lines, new fuel pump, new fuel regulator - which leaked once plumbed in, so waiting on a replacement from PMB. The car's summer was spent up on jack stands; annoying...
On a positive note, to help alleviate future embuggerance, a couple of local places here in Oregon, USA do sell Ethanol-free gasoline. That'll be the main fuel choice once I get everything running again.
- Tony