The mixture screws are all backed out to the point where the O rings are no longer seated in the housing. Is this an indication that the jet is undersized?
Yours are about 10 turns out.
Jets probably 2-3 sizes too small.
Wait until after you swap the vents and check again.(shouldn't matter, but try anyway.)
2 turns is the accepted reference point, less might work better with bigger idle fuels, more can go smaller.
I had best results with larger than "optimal" idle fuel jets and screws at ~1/8 turn, but that was with 44IDF/36s on an otherwise stock 1700.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
I took it for a spin after installing the 30mm venturis & it accelerates better without hesitation but it now snaps & pops a lot on deceleration. When the book says to go up a jet or two, what increment would they be suggesting? the main jets are now @ 140
If you had EFI the fuel cut would eliminate that, but with carbs you are still sucking fuel through the idle ckt.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
Not a single snap or pop in 60 miles with the 34mm venturis though. I don't think it developed leaks in the mile or so that I drove it with the 30mm's. I think the Delorto book said that this could be a symptom of an over lean condition - I'll check tonight
The lean condition popping & snapping reference that I recalled reading about was only at idle speed. The Superperformance book describes that the mains are sized in relationship to the size of the venturies installed. With the 30mm in, I should be using approx. a 120 main. I guess that was what all the popping & snapping was about while running the 144 mains with the 30mm venturis. This morning I plugged in the 122 mains that were originally installed with the carbs & what a difference! The thing has buckets of torque & accelerates smoothly through 4500rpm. Even with the 35" rear tires that I know are way oversized, it is still hauls ass. I think it lacks the aggressive top end that it had while running the 34mm x 140 combo so maybe down the road, I explore the larger venturies (maybe 32mm). I am not sure how much a vacuum advance distributer will help me but I have heard that installing one may help to make it a little more driver friendly while increasing gas mileage.
So if I have the mixture screws backed out further than 2.5 turns to achieve the highest idle, is this an indication that the idle jet should be larger? I am not sure if the screws affect both circuits. My main concern is that the screws are so far out that the O rings will not seal out dirt. The screws are also a bit on the loose side without the friction of the o ring & I am afraid that they will vibrate out.
Mains won't affect idle characteristics. You will need to up your idle jets since a) they are too small and b) you have them turned out because they are too small. There will be an idle jet for each circuit.
The idles and mains interact somewhat at the transition, but its not necessarily a bad thing.
Get or drill out your idles if yu have a jet reamer/drill kit, then order a set in the size that works.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
I checked the oil @ 250 mi. & the dip stick came out with crème colored foam on it. Oil pressure is good so I hope that things haven't been compromised. I haven't ever seen this before on any of my vehicles but from what I have read, it is caused by water in the oil. I removed the filler cap & also noticed a small puddle of condensation on the ledge inside.
I have breather tubes from each valve cover & from the stand pipe that go to a breather box but I wonder if the condensation is making it out with the length of the tubing and lack of blow by? Any condensation left in the tubes would gravity flow back to the engine since the box is located above everything. Has anyone else had this issue?
Oil is Brad Penn & it is supposed to have anti-foaming agents added.
My breather tube running from the alt stand to the elevated box, had a low point that had filled with fluid thus creating a vapor barrior. After re-routing the tube so it was continuously gaining elevation, the barrier is gone the foam has dissapeared. I also noticed that the piece of foam that EMPI put in the box does not breath at all. I replaced it with some foam from a shop vac element & sprayed it with foam filter oil to keep contamination in the box & out of the tube & engine.
Last edited by evernon on Tue Jun 09, 2015 8:28 pm, edited 1 time in total.
Update - I have installed the larger idle jets & it does run a little better. Still has a bit of a stumble between limited & moderate throttle. Wow though, if I get on it, the thing is very torquey & even with 35" rears, it easily breaks free in 2nd on dirt even in a straight line. One thing I have noticed is that it has always had a bit of a hesitation while cornering to the right. A few days ago, it had this cornering hesitation & then it seemed to be continuous following exit of the turn. It idles perfect but when you accelerate, it lugs and hesitates but no backfires or misfires. My 1st attempt to fix involved pulling all the jets & making sure they were not clogged but no luck. I then proceeded to replace the cap, rotor, points & condenser but this also did not help. I am thinking that my next move would be to try & isolate the bad side & disassemble, clean & re-install one of the DRLA's. I have read that they do get clogged easily & that there is an update kit that improves this problem. After looking over my filter elements, I believe that there could be some contamination as I can actually see daylight through pores in the cloth elements. I just checked the valves as part of the break in service & the only other thing I can think of is that maybe it is related to a clogged fuel filter or poor fuel supply from the pump. I kind of doubt that though this early on.
This is a good one - the hesitation & loss of power at high rpms was not related to carburation. I had routed the spark plug wire for #1 cylinder over the top of the shroud & it was being pulled into the edge of the cooling fan when the airflow got strong enough or when I turned sharply to the right! The friction had cut grooves into the insulation on the wire & it only grounded out when airflow or gravity caused it to contact the edge of the fan.
Engine is going strong now with 1500 mi. I am thinking of giving my son my 009 and replacing it with a SVDA. I actually borrowed the 009 from my rail & now my son wants to revive it! Regardless, from what I have read, I would get better performance & fuel economy with an SDVA. Right now, the engine runs great if I give it a lot of throttle. When I drive normally though, there is a very noticeable hesitation just off idle to about 2000rpm. I mostly notice it in 1st gear but it also can be felt in 2nd & 3rd if I am driving conservatively.
Aircooled.net is advertising a Petronix SDVA which says it is compatable with DRLA's. Has anyone tried this combo? I have read that the vacuum ports on the Dellortos do not work well for this application. They also make an SDVA which uses real VW cores & costs another 50
I also have a 231 167 070 Bosch in my resource pile. Not sure if it would be worth re-building & trying out.
I've been driving this for several years now and am finally getting a round to refining things a bit. The 36 DRLA's work pretty good overall running the 30mm venturies with 122 mains. Performance is very torquey off the line if i give it some pedal but if I just normally accelerate like in traffic, there is a bit of a stumble off the line, only noticed in 1st gear. With less pedal off the line, it actually feels better than with moderate pedal. The carbs have 50 accelerator pump jets and I am wondering if increasing these will help?
To get more power at higher revs, I am thinking of increasing the venturies to 32mm and upping the mains to 130. Im not sure how this would affect the stumble zone. I don't really need more top end but if I can gain some there without losing low end, more is better right?
I'm also looking into replacing my 3.5" cloth filters with 6" foam 2 stage UNI filters. The cloth filters don't do a good job of keeping dirt out and the increased size will maybe help with flow patterns from what I have read.
