Just spent another 40 bucks to rebuild these damn carbs. Put them back on and I still have the same problem of carbon building up on the plugs. Could the PO of the the carbs made the hole in the jets bigger? Can I have this problem because the rings haven't seated yet? I know the valves need adusting could any of these be the cause??

yes. jet guages are made for this purpose. it's fairly common to ream small, lesser-used jets to bigger sizes.

it's also possible that your plugs are simply way too cold. what kind and flavor of plugs have you got? are you using the stock ignition system or something else ? are you using the proper grade of gasoline ?

it could be a ring seating problem, i suppose - it is oily or just sooty ?

i wouldn't suspect the valves of this but if they need adjustment, do that.

have you run any kind of exhaust-gas analysis? what do your CO and HC look like ? is your timing correct ?

exactly what sizes of idle, main, and air correction jets do you think you have (pending gauge verification...)? what is your altitude ?

OK lets see if I can answer all these questions:
Champion plugs from flaps, crapy 005 dizzy, regular unleaded gas, plugs were oily untill most resent rebuild, mixture screw o rings to big now they are sooty, was getting black oily crap out of the tail pipe, now seems to be clean, my jets are Main 115, Idle 50 not sure the air. Also dual weber 40 IDFs.

Champion what plugs? The heat range is what's important to know. If the plugs are too cold, you're never going to get it to run well. Is the carbon only building up on the rim around the center electrode, or on the ceramic portion of the center electrode, or is it covering the whole electrode (black sooty fluffy looking stuff)? Plug reading is something of an art, and some of the stuff you read about plug colors was written 30 years ago, and only applies if you're running the same gasoline that was available 30 years ago. The addition of oxgenators and the removal of lead since then have both altered the colors seen on the plug.

Unless you're really wanking on the engine and doing a plug chop (that is, killing the engine while it's at high revs, and coasting to a stop, then checking the plugs), the color you see is also completely unaffected by the air corrector jets, which really only kick in at high revs. Idle or run at light throttle for even a few minutes and the color you see is dominated by the idle mixture screws and the idle jets.

Try this: engine warmed up, screw in the idle mixture screws half a turn at a time (doing all four), until the engine starts to stumble. Back them all out a quarter turn. Drive around the neighborhood for a few minutes at light throttle. Check your plugs now. If they're still covered in soot, the plugs are way too cold, or you have a major leak internal to the carbs (much less likely if it's all four plugs), or your idle jets aren't really 50s anymore (possible, but easy to fix, though it will cost you another $20 for a set of idles). Pull the idle mixture screws out all the way and look at them, too, and make sure the tips aren't buggered. If the plugs AREN'T covered in soot, then you've found the problem: you just have the idle mixture set too rich. 2.5 turns out from lightly bottomed is the usual starting point, but if they soot up at that setting, you need to lean them all some.

well - there are lots of Champion plugs and i (personally) don't like any of them ... find yourself some nice Bosch W7 copper plugs or the NGK equivalent ^6, maybe) - nothing colder. -- sorry, i can't remember the reach code and interestingly, there are no spark plug designations in the Spec Book. for some reaon, i'm remembering W7BC...

on the distributor i'll assome you meant 009 - an 050 would be a good choice, and a stock dizzy would be some flavor of 205...

all bets are of until you get the right O-rings for the mixture and air pleed screws ...

50 seems pretty small for an idle, if correct, and 115 sounds small for a main -- but i don't know your displacement, nor what kind of cam you're using.

i will assume from your location that you're near sea level ...

The PO put it the cheap dizzy you see in Tweeks, I did replace the O-rings with ones that fit. My engine is a 70 1.7, with 96mm big bore and a 71mm stroke. I haven't had the car on the road since the new rings, have just let it idle.

The carbon covers the entire electrode. The mixture screws are nice and sharp at the ends.

rings are never gonna seat at idle; you need to build some cylinder pressure ...

Breaking-in your rings properly is one of the most important to do. Many people don't know how.

Read this artical: Break-in Secrets

I bought a new Harley back in 99. Did everything the owners manuel said. "Don't go over 2,000 rpm for the first 50 miles" it said. After 1,000 miles I had the H-D shop put the Big Bore Kit on. When I got my old P/C I noticed there was a good bit of blowback showing on the piston and alot of black carbon on the piston top. I asked the mechanic why this happened. He said (off the record) if you baby it the first 50 miles the rings won't seat completely.

The above artical is very good reading. Not only for rebuilds but for new cars too.

Ralph

74 2.0

Most carb problems really are timing problems.
Post a pic of those plugs and I'll tell ya what the issue is.

BTW you don't have a 1.7L no more You got a 2056. What heads not that it matters other than smaller valves.

I agree with all posted above.

I will be firing up a 70 1.7L this weekend D-jet FI.

I will pull the plugs and post a pic this Friday. Saturday I will take it for its maden voyage. I have the original 1.7 heads, with these tri racing rocker springs (will be replacing them with more reliable ones this winter).
Thanks all.