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Timing questions again

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A

aroostok

Jedi Hopeful
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Have a '76 B converted to dual AUD326 carbs (from a 1969, I believe with spring loaded needels, recently rebuilt and shafted). Have had a persistent miss as if carb balance was wrong (checked and set) or not enough fuel. Electronic fuel pump (has plenty of fuel). Am contemplating changing to a 25D distributor since I really can't get the darn electronic sensing unit to stay put on a Crane electronic conversion. Even if I don't, very confused about initial static (and strobe) timing. Bently manual states that the vacuum advance is present but not connected (for 1976 18V801 engine)and gives me various centrifugal advance readings at different rpms. If I put in the 25D4 points distributor which has also been rebuilt it gives me once again a number of readings for different rpms but much different and with the vacuum tube disconnected (and I'm assuming plugged). Can anybody explain what I should do here. I know I sound dumb on this but I have tried everything and just don't know which settings I should be using with the dual carbs and points distributor, or even with the electronic. I just cannot seem to get the kind of response I should be getting, especially at higher rpms.
Thanks
 
With the 25D, points gapped at 0.015" and a static light I set mine at 8~10 deg. BTDC, but I've an 18GB so compression is a bit higher than the later ones (not to mention the tweaks I've done). Shouldn't make that big a difference tho. The later dizzy had a vacuum RETARD unit IIRC... Somebody in here will soon straighten me out on that... but: as I'm an Old Fart and like to SEE my electrons flow I keep the 25D with points and have the mechanical advance curve dialed in to that of the "Special Tuning" chart, with NO vacuum tube. Weber DCOE and no stumble. Sounds like you've an advance issue to me.
 
I installed SUs on my '76B when I lived in New Mexico at about 7,500 ft. Got it tuned up and it ran well. Moved to TN (West Knoxville) and had a slight miss. Remembered reading about people installing K&N airfilters which provided more air than stock which caused a lean-miss. The cure was co contact Joe Curto and get AAA needles. I did so, finally got it retuned and it runs great.

Larry
 
Larry....you also dropped several thousand feet - thus the different needles?
 
Aroostok, Why not shift to a pertronics system. your timing will stay steady as a rock. Plus it is simpler and all contained under the cap.--Fwiw---Keoke
 
Hey DR-E! them not electrons you seeing them just sparks cuz you can't see electrons they only live in electronic ignitions.---Keoke /ubbthreads/images/graemlins/yesnod.gif /ubbthreads/images/graemlins/laugh.gif
 
Sparks GOOD! Sneaky, Hidden 'lectrons BAAAD!

If'n it's sparkin' it's runnin' in my book.
 
Tony,

I don't claim to be a mechanic, but I think it was almost too lean at 7,500 ft and when I moved to TN and lost altitude it got worse; bad enough to try to fix. With the denser air I needed more fuel. The car idled fine at both altitudes but at road speed in TN there was an erratic miss. Changed from AAE to AAA needles and I no longer have the miss.

Side note: this is about the time I got Des Hammill’s book “How to Build & Power Tune Su Carburettors”. The tune up procedures in this book are much simpler than others and they work!

Larry
 
Well, the next time you're out for an hour cruise - that's about how far you are from me!
 
Tiny,

Getting down to your place is one of the things on 'my list', I just don't know when I will get time. I have a house in TN, my wife is in TN, but I will be spending a LOT of time in the DC area or on the road for the next year or so. I must have missed something when I retired in July !???
 
Hey, Larry - I retired from the Army in 1993 & retired as a high school teacher in 2004....this year I've already traveled 22 weeks for the Army!
 
TDY by any measure.

Must be nice to be loved. /ubbthreads/images/graemlins/wink.gif
 
TDY every time, Doc...& they treat you better as a retired colonel than they did as an active one!
 
<green>

Is my envy showin'?

</green>
 
Tony ,

(Sorry for “Tiny” in my last post; must have been late)

Don’t know about you, but 20 some years of TDYs tends to take the fun out of it for me; just something you have to do.

Some day I would like to hear about your transition from Army colonel to school teacher! That must have been an experience!

Larry
 
Larry - you wouldn't believe it!

Actually, now they ask me if I want a king-size room, which seat on the plane I want, gave me an AMEX to pay for everything (can even draw cash out of ATM for meals, etc), provide rental car...its almost like going on a egular business trip for whatever corporation!
 
heh... I remember bein' TDY about anyplace and able to get 'per diem' for off-base accomodations. Used to be a coups: We'd ask the poor shlub at the BAQ if he'd SIGN for all the MoPic equipment, to be put in HIS safe... Usually they'd baulk and give us the "chit" for off-base accomodation... We thought we were livin' in high cotton then!

Tony has apparently taken that to a new level /ubbthreads/images/graemlins/wink.gif

shhhh.... sorry!
 
I get my orders, an airplane ticket & hotel/rental car confirmation in FEDEX about 48 hours before I fly...or, if I want to drive, that authorization...stop by the ATM on the way to the gate, grab a few hundred bucks....if it had been this easy, I might not have retired when I did!
 
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