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> Okay, help with my motor, was: "carb dial in help? (webber IDF 44)"
VaccaRabite
post Jul 5 2008, 12:31 PM
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*edit* Note, cylinder bank 3/4 is not firing. Plugs are oil fouled. All four cylinders have decent compression, considering that the rings probably are not set yet. Carbs are fresh rebuilt, I have yet to check spark.*/edit*

I have set my idle at 1K rpm.
Idle adjustment screws for the 3/4 bank is almost all the way out.
Idle adjustment screw for 1/2 bank several turns in.

Both carbs are idling at 5 kg/h according to my flow meter.

Mix screws for all 4 carbs are 2.5 turns open.

When I open the throttle to ~3K rpm, the 3/4 bank only sucks slightly more air. The 1/2 bank jumps up to about 15 kg/h.

So, where am I off.

I have my weber tech manual too, but thought I would ask here to see if I got a faster "ah-ha" type answer (like usual).
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VaccaRabite
post Jul 6 2008, 08:51 PM
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Okay, so I got a break in the weather and ran out to do some tuning.

I took some pictures for Jake. His guess is that my vents are 34mm.
(IMG:http://farm4.static.flickr.com/3148/2642903679_3dfcbc4d84.jpg)

I took the carb off the manifold and inspected the venturi closely, but could find no marking, so it must be engraved on the under side (which at the moment I can not get to).

I put everything back together and started really examining the linkage. I noticed that the geometry from the pushrod that worked the throttle was steeper on the 1/2 bank then the 3/4 bank - seemingly by design. I am guessing this is why the 1/2 bank is doing most of the work.

So, I mounted the 3/4 pushrod farther back on the linkage arm. I also turned the turn buckle to lengthen the arm a little. Then I powered up the system, and let the fuel pump run for a few moment to refill the float bowl on the carb that I had pulled off.

Suddenly I smelled gas. I must have bent the float arm a little, as the 1/2 carb was overflowing with fuel. *DAMMIT* I sopped up as much as I could, and took the carb apart. Reset the float to 10mm to closed.

Not knowing what to do about the gas sitting in the intake manifold, and not having a baster to suck it out, I ran the starter without fuel or spark and pumped it out. I suppose I need to remove my exhaust and drain that fuel out before I blow mu muffler off. I'll have to do that tomorrow.

I'll test to make sure that my carb float shuts off as it is supposed to first though.

I do not think that these carbs have choke circuits, but thats something that I will look for tomorrow.

Zach
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Posts in this topic
Vacca Rabite   Okay, help with my motor   Jul 5 2008, 12:31 PM
Vacca Rabite   Freshly rebuilt carbs, by the way. All the passag...   Jul 5 2008, 12:36 PM
Vacca Rabite   Well, all things considered, for an engine running...   Jul 5 2008, 01:21 PM
ArtechnikA   When I open the throttle to ~3K rpm, the 3/4 bank...   Jul 5 2008, 01:21 PM
Vacca Rabite   Compression numbers - keep in mind, this is a fres...   Jul 5 2008, 01:39 PM
ArtechnikA   What do I want to be looking for? Spark next I g...   Jul 5 2008, 02:25 PM
Vacca Rabite   Engine is a 2056. Don't know the venturi size,...   Jul 5 2008, 02:35 PM
SirAndy   The 3/4 bank is still sucking less then the 1/2 b...   Jul 5 2008, 03:11 PM
Vacca Rabite   Its raining now, so I can't run the engine w/o...   Jul 5 2008, 03:32 PM
ArtechnikA   you're seeing a huge difference in airflow, an...   Jul 5 2008, 06:13 PM
!   Ya needs a UNISYNC..... Disconnect the linkage an...   Jul 5 2008, 06:25 PM
Vacca Rabite   Ya needs a UNISYNC..... Disconnect the linkage an...   Jul 5 2008, 09:35 PM
ArtechnikA   I am using a syncrometer, but it is not Unisync b...   Jul 6 2008, 07:17 AM
Vacca Rabite   BTW - as long as you are checking everything - ba...   Jul 6 2008, 02:32 PM
Gint   You did measure the airflow with the linkage remov...   Jul 5 2008, 06:53 PM
Jake Raby   Why are they oil fouled? Carbs won't cause tha...   Jul 5 2008, 07:31 PM
craig downs   Do they have the old cold start thingy on the side...   Jul 6 2008, 11:52 AM
rhodyguy   while there may indeed be other issues, here's...   Jul 6 2008, 12:08 PM
!   :agree: One thing I have found...and it really p...   Jul 6 2008, 12:16 PM
Al Meredith   I had a lot of trouble with #3 oiling up and not h...   Jul 6 2008, 08:01 PM
iamchappy   Over the years i found that for some reason i foun...   Jul 6 2008, 08:16 PM
!   No but I CAN Tuna Fish....   Jul 6 2008, 08:17 PM
Jake Raby   Al, go ahead and bolt on the Chinese carbs and tha...   Jul 6 2008, 08:25 PM
Vacca Rabite   Okay, so I got a break in the weather and ran out ...   Jul 6 2008, 08:51 PM
craig downs   Your carbs have the choke circuit as I can see the...   Jul 7 2008, 01:35 AM
ArtechnikA   Your carbs have the choke circuit as I can see th...   Jul 7 2008, 06:12 AM


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