Jetting Recommendations for Weber 44s

fido · Post by **fido** » Sat Oct 21, 2006 8:34 am

sounds like a problem with the progression from idle to main circuit.

Try putting the 1.75 air correctors back in - will fatten up the main circuit.

Post by **Sluggo** » Sat Oct 21, 2006 10:42 am

The stalling turned out to be the fuel pump relay. I went with a cool little round German Hella relay from the 50's. Apparently the base rotates in & out of contact. I'm gonna try crimping it down. I'll carry another relay just in case.

I misplaced my extra jets! I've looked everywhere. I'll have to tear apart the Bus & workshop today and try to find them. I'll close off the Air Adjusters and see how that plays out.

I figured this would alter the timing but I checked it out and I'm still at 7.5 BTDC with 32* advance. Idle at 900.

Post by **Sluggo** » Sat Oct 21, 2006 2:32 pm

Changed out the 60 idles for 65's. Closed the Air Adjusters. Straightened out the arms. Readjusted the idle.

NO BOGGING!!!!!!

I only took it on the streets up to 45. But I had loads of power, no bogging & no popping! I'm gonna take it on a short freeway run to Burbank and see how it goes. I'm sure I'll have a little more tweaking to do but I am happy as hell right now!

Thanks for all the help to everyone here &Jake and everyone else at the Shoptalk Type 4rum
http://www.shoptalkforums.com/viewtopic ... sc&start=0

fido · Post by **fido** » Sun Oct 22, 2006 1:24 am

Thats great :)

Now you want to get that 32* max centrifugal advance down a tad - 28 to 30 at most - will help with the top end a bit and help keep those heads a little cooler.

Post by **Sluggo** » Sun Oct 22, 2006 9:54 am

fido wrote:Thats great :)

Now you want to get that 32* max centrifugal advance down a tad - 28 to 30 at most - will help with the top end a bit and help keep those heads a little cooler.

Actually, it's 32* with vacuum. I'll check the centrifugal advance today. So it's okay if I'm at 5 BTDC (for example) as long as it keeps me from going over 30* advance?

fido · Post by **fido** » Sun Oct 22, 2006 11:55 am

Your stock distributor shouldnt have that much advance. It'll probably end up somewhere around 5-8* BTDC at idle (I'm assuming you are not running vacuum retard) with a max centrifugal advance of 28-30.

32* with vacuum sounds a little low - although I have never run 44's with a vacuum distributor to know if that is unusual or not. Certainly on my 36 DRLA's I get >40* with vacuum, just like the stock carbs (my mac centrifugal is set to 29). I use an in-line anti-pulse valve on the feed to the vacuum can - this smooths the pulses you get from feeding from just 1 cylinder and helps the signal acheive a full 12 degrees vacuum advance. If you dont have one, I'd suggest getting one. I imagine most good carb shops carry them. Got mine from www.dellorto.co.uk - although they are in the UK, so maybe no use for you.

Post by **Sluggo** » Sun Oct 22, 2006 12:35 pm

It's not a stock dizzy. It's the Aircooled.net SVDA (check my tagline). They said it may take a few months of driving to get full advance. Something about breaking in the diaphragm. I'll time it to 30 max centrifugal advance today and see how that goes. I'm getting much lowere temps except at freeway speed. Maybe that will help out.

I can't believe the power and torque this thing has now! Proper jetting & exhaust makes all the difference in the world.

vdubyah73 · Post by **vdubyah73** » Sun Oct 22, 2006 5:27 pm

Sluggo wrote:It's not a stock dizzy. It's the Aircooled.net SVDA (check my tagline). They said it may take a few months of driving to get full advance. Something about breaking in the diaphragm.

Thanks Sluggo you probably just answered a problem I'm having with my buggy popping every so often at a very lite throttle position. Partial throttle is where vacuum advance kicks in. I have an aircooled.net svda on my engine with about 2500 miles on it and this problem developed slowly over the summer.
Note to self check timeing at partial throttle.

Bill

spiffy · Post by **spiffy** » Sun Oct 22, 2006 6:12 pm

My ACN dizzy took about 3K to "break" in....now she feels like buttah.

Post by **Amskeptic** » Mon Oct 23, 2006 9:25 am

Sluggo wrote: I'm sure I'll have a little more tweaking to do but I am happy as hell right now!

Randy, I am glad to hear you have power now. I really enjoyed how smooth your engine was when it was just trundling around surface streets. The thought of that smoothness and power as well. . . makes me jealous.

Total centrifugal advance with a Type 4 engine can go up to 32* without any problem if you need to get 7.5* squared away at idle.

Review all of the advice you have been given.
What advice helped?
What advice hindered?
What advice didn't make a difference?
Did you have people advising some fancy exhaust system
to go with your honkin' carbs?
Did the stock exhaust improve anything?
If so, what do you say to those who claim it causes overheating due to back-pressure blahblahblah?
Colin

Post by **Sluggo** » Mon Oct 23, 2006 10:42 am

Amskeptic wrote:
Sluggo wrote: I'm sure I'll have a little more tweaking to do but I am happy as hell right now!
Randy, I am glad to hear you have power now. I really enjoyed how smooth your engine was when it was just trundling around surface streets. The thought of that smoothness and power as well. . . makes me jealous.

Total centrifugal advance with a Type 4 engine can go up to 32* without any problem if you need to get 7.5* squared away at idle.

Review all of the advice you have been given.
What advice helped?
What advice hindered?
What advice didn't make a difference?
Did you have people advising some fancy exhaust system
to go with your honkin' carbs?
Did the stock exhaust improve anything?
If so, what do you say to those who claim it causes overheating due to back-pressure blahblahblah?
Colin

You're the second person (with knowledge of Type IVs) who has said they are jealous!

Bottomend said the same thing! I really am proud. Especially for a first build! It wouldn't have been possible without Bottomend.

My centrifugal advance is 24*. Should build up as I drive more.

The jetting advice given by Jake, Twysted1 & Piledriver over at shoptalk was invaluable.

vdubyah73's advice about closing the air adjuster and straightening out the arms was a major key.

Fido's advice was also very helpful.

No one's advice hindered me at all.

Jake and several others recomended the Econo Header. I just don't have $450 right now. + whatever $ for the muffler.

Stock exhaust improved everything. Vacuum, smoother running, Head & Oil Temps, road clearance, exhaust smell being sucked into the cabin. It's even easier to tune, just like I was told.

The Econo Header may be better for my carbs. I haven't used it so I have no idea. But I am very, very happy with stock. Converting from that piece of crap to stock is an amazing difference. The only think lacking is the cool factor. Of course I'd only be cool until I was stranded on the side of the freeway with a dropped seat or cracked head. I could easily see the EMPI causing back pressure. The stock set up appears to breath fine.

I'll be cutting open the EMPI to show what the inside looks like. Now that I've taken it off I can see even more rust. Especially around the welds and seams. After only 1 year and less than 500 miles of use. I even stripped off the original paint (which was flaking off before I ever installed it) and painted it with VHT. Everything else I've painted with VHT has held up great. Started coming off the muffler after a few weeks.

Post by **Sluggo** » Mon Oct 23, 2006 9:31 pm

Update:

Everything is still just so much better and I'm still very happy. But a few things have arisen. I'm dieseling a little when I shut down. I think I'm running it a little rich because I'm trying to eliminate this little pop I get when I let off the the gas to shift from 1st to 2nd. It also happens when I rev in neutral. When coming down from a high rev (3000-3500), I get 1 pop just before it reaches idle. I turned out the mixture screw trying to remedy this and now I think I'm running rich. Which would probably cause the dieseling.

A pop in this new muffler is amusing. It sounds like a popcorn kernel popping inside a thin aluminum pot when I was little.

vdubyah73 · Post by **vdubyah73** » Tue Oct 24, 2006 3:53 am

You may never get rid of the little pop! fast as i can , gotta go to work. When you let off the throttle the butterflies slam shut. The fuel in the runners now doesn't have enough air to burn efficiently. they hit the exhaust and as they exit they ignite.In the '70's, for emmissions car makers put a solenoid on the throttle linkage to slow the closing of the butterflies to remmedy this. Not all the fuel would pop off on the way out and it was a way to reduce emmissions. Imagine that, reducing emmissions by allowing more fuel/air mixture to continue thru the engine without any demand for it.

Bill

fido · Post by **fido** » Tue Oct 24, 2006 8:12 am

24 max centrifugal will build alot of heat in those heads. Up it to 28-30 and you'll be alot cooler, and have better power too.

THe centrifugal advance will not increase with more use of the distributor. Hot heads may be contributing to the dieseling.

Post by **Sluggo** » Tue Oct 24, 2006 7:33 pm

fido wrote:24 max centrifugal will build alot of heat in those heads. Up it to 28-30 and you'll be alot cooler, and have better power too.

THe centrifugal advance will not increase with more use of the distributor. Hot heads may be contributing to the dieseling.

With centrifugal advance at 30 my static timing is at 10BTDC. Turned the mixture screws back in. Now thay are at about 1 1/2 turns out each. It did seem to get a little more power and I haven't had any dieseling since. I think I might change out the 65 idles for 60s.

Itinerant Air-Cooled

Itinerant Air-Cooled

Jetting Recommendations for Weber 44s