weber 44 fuel mileage

[bugcollections]

A bit of background: Have a baja that is set up as a beach cruiser and runs a VW roof rack with a surfboard mounted on it. This baja has been driven about 160,000 miles and has been to both coasts several times. Neeless to say it gets lots of highway miles. Currently running a 2007cc engine with CB 044 heads, Engle 110, and 8.5:1 compression ratio. Had been running a set of weber 34s on this engine which now has about 40,000 miles on it. The 34s had about 100,000 miles on them, and I decided to try some 44s. In all my travels with the 34s and with all of the non-aerodynamics of a baja with a roof rack and surfboard it normally ran 20-21 miles per gallon fuel mileage cruising at the speed limits and maybe a bit more. Backing off on the speed a bit and cruising at 60-65 would result in mileage as high as 23-24 and sometimes 25 which I always thought was very acceptable for a baja set up as this one.

I just installed the 44s and made my first trip to a VW show: 155 miles of highway cruising at speed limits and barely managed 15 mpg. Carbs are brand new, came from CB supposedly jetted for my engine. Main jet 1.85, idle jet .60 and air correction 2.00. Engine runs great with the new 44s, smooth as silk and excellent throttle response. Very happy with performance, very disappointed in fuel mileage. I am not an expert on Webers, but they have been adjusted properly and synced. Appear to run perfectly except for the fuel consumption.

Asking for suggestions before I start tinkering. One thought: these things came from CB with a "new" type of airfilter. Not like the old style of Weber and Dellorto filters, but a wire mesh sort of structure which is wrapped with two layers of heavy foam, instructions for which call for soaking in oil and then squezing out the excess oil. I now have about 400 miles on them and the foam is still very oily and it appears to me that the foam is so thick and soaked in oil that the carbs are being choked down and not able to breath enough through the filters. Almost like you were running with a choke on. Initial thoughts are to go back to the original style air filters and see if that helps. Engine appears from exhaust to be running very rich but my initial thoughts there were that there is so much oil in the foam of the filters that it is simply sucking in a lot of oil from the filters; that and the fact that the carbs are working hard to breath through all that foam.

Any and all thoughts that someone may have would be appreciated. 15 mpg gallon on a car driven on the highway a lot is not really acceptable. I was happy with the mileage with the 34s for a baja, but not with 15mpg.

[Slow 1200]

185 main jet

[Quokka42]

Both idle and main jets seem a bit big to me. Scoot on over to aircooled.net and read their jetting instructions a few times. Try their suggested jets as a starting point and be aware you might need to play with your ignition tiiming a bit too.

Some people are going to be upset if your mileage is not as good as the 34s, and it may never be, but I suspect you can get it a lot better. You should notice an improvement in your engine's response as it gets closer to optimum tune as well.

If you get the jetting right highway mileage should be as good or better than the 34s, around town it will depend a lot on how you drive.
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There has only ever been one man who was perfect, and they nailed Him to a cross.

[madmike]

I agree with Q42,un-soak the filters ur not running the Baja1000 store the roof rack & board, and should be around ?? 55 idle and 155 mains
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'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[drumbum68]

I would start with 50 idles, 135 mains, and 200 air. Maybe a 180 air.

[Dale M.]

I agree with others the mains and idles are to big... I run 2000cc motors and use idles around 55 and main around 135....

Dale
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“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
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All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[bugcollections]

OK, went back and looked at the note on the box from CB. The note says the jets have been drilled to: Mains 1.55 (when looking at the handwritten note the first 5 looked like an eight), so I am now assuming it is 1.55, not 1.85; and the idle is .60 and air correction says 2.00. I am going to pull the foam cleaner elements and go to the more standard filters for the webers and see how much improvement I get there. Since the note says they have been drilled for sizes I am assuming whatever it says on the jets is not correct.

Next step is to experiment with jetting. And Dale; at what altitude are you running those settings. I am basically at sea level.

[modok]

I do not see any reason your engine would require extra large idle jets.
Go down to 55 at least!

[bugcollections]

I changed out the air filters today, back to original style Weber/Dellorto and will see if that has any impact. Next step is to go down to .55 on the idle jets. Depending on what happens there am going to try 1.45 mains.

[bugcollections]

Changed the air filters. Not much help. Just changed the idles down to .55. Going to go out and run it tomorrow and check the plugs and see what we have now.

[bugcollections]

OK, now changed idles down to .55 and mains down to 1.45. Still appears to be running too rich. Going to run it a bit and check, but guess the next step is to decrease the mains down to 1.40 or even 1.35.

[Teeroy]

Double check your float levels and fuel preasure.
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Pres. Rivercity VW Club www.rcvwclub.org
Founder Derr Wheat Panzers (DWP)
ARR #3
www.autosportsnorthwest.org

[flyboat]

[bugcollections]

[veedubcrazy]

Sammy, I have 44IDF's as well so maybe it will help. Clean filters, check float levels, try 55 idles, 140 mains and 180 airs. Also, make sure you have the F11 emulsion tubes. These were set up by John at AC.net for me and they do fine.
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1967 Deluxe Sedan

[ALB]

[bugcollections]

Just checked the plugs after about 20 miles of running with the 1.45s and .55s and they look pretty good (compared to the 1.55s and .60s they look great) but could probably stand to run just a bit leaner. Am going to drop the mains down to 1.40 and idles down to .50 and see what they look like.

In the meantime I decided to check the Beck 550 out. Haven't had it long and haven't really put enough miles on it to see what it was doing; but pulled the plugs, richer than heck. It is a Beck turn-key car and has a CB Pat Downs turn-key 1915 with 44s. Pulled the jets and they are the same as the 44s that I got from CB. 1.55 mains and .60 idles. Next step in this process is to work on the jetting in the 550.

[flyboat]

[MURZI]

Buy a wideband o2 sensor. Best tool I have bought in years. I don't guess at jetting anymore, I tune it to exactly where I want it. What I have found by using it is that every engine tunes differently.
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62 vert
2276
Tim’s welded heads
45 Dells
A1 sidewinder
Fk44 cam

[bugcollections]