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Posted by: NineOneFour Nov 7 2008, 01:49 PM

I bought a carb sync on eBay for my 44's. I was looking at the Synchrometer STE SK, they were all about the same price and shipping costs. I found a place that was close to me and would only take 2 days to get the sync to me at no extra cost through USPS so I chose that vender.

2 days later I'm unwrapping the sync and going to work. I do a prelim check and the barrel for #1 is drawing half as much as the other 3. I do a little adjusting the motor smooths out a bit I check again and #1 still drawing WAY less than the other 3 (That'll be the question part) ANYWAY As I pulled the syc of the #1 again I here the sound of something metallic bouncing on the tin. I look around and find the small brass counter weight that's on the inside of the sync... I was soooo luck that the weight fell out just outside of the carb and not inside carb with the motor running.

This is the weight.


And this is where it goes in the sync.




I checked the sync and upon close inspection it was not a made in Germany STE SK, it was a knock off made in China. They looked EXACTLY alike with the exception of the "STE" in the right hand bottom corner, which was missing from the one that I purchased. I looked at the site that I bought it from, they use the same SK or BK designation with the same model numbers but never said it was a STE. I called the vendor and he agreed to refund my money.

I called around to a few shops in So Cal and they said that most shops are selling the knock off, instead of the real thing. More money in it for them...

My suggestion is that if you own one of these knock off sync's... get rid of it. It's better to go out and spend $40 bucks on a real STE than rebuilding your motor.

Now, back to the question part. Why do you think the #1 barrel is flowing half of what the others are?

Thanks

Posted by: SirAndy Nov 7 2008, 01:53 PM

Did you adjust the valves first? Because otherwise, syncing the carbs is a waste of time ...
Andy

Posted by: messix Nov 7 2008, 01:54 PM

valve adjustment?

Posted by: NineOneFour Nov 7 2008, 02:14 PM

It's had maybe 30 minutes on the motor since the valves were adjusted, but we'll check it again

Thanks!

Posted by: jmill Nov 7 2008, 02:20 PM

I assume your doing this at idle. If so there is an air adjustment screw you need to tweak. First make sure that the butterflies are all closed the same - check with a feeler gauge. Check that the holes in the butterfly are the same size and not plugged up. Adjust the air adjustment screws. You may have to turn 3 down and one up.

I never really liked that style of syncrometer. I like the kind with the little red plastic ball.

Posted by: NineOneFour Nov 7 2008, 02:24 PM

I am doing it at idle, these are new 44's but I'll check butterflies. When you said to check with a feeler gauge, is there a specific gap it should be at idle?

Rodger

Posted by: jmill Nov 7 2008, 02:34 PM

My Weber tech manual is at the house and I'm stuck at work. I believe there is a specific gap. That gap isn't as important as them all being the same. The gap changes as the shaft on the butterflies wear. With new carbs it should be fine. Adjust your air adjustment screws. Set them all the same amount of turns off the bottom and tweak till they flow the same.

Posted by: NineOneFour Nov 7 2008, 02:36 PM

Thanks Alf

Posted by: jmill Nov 7 2008, 03:03 PM

Remember that as you adjust the air you have to adjust the fuel. Lean pops to the face are no fun. As you're waiting for the new syncrometer to show up I'd invest in the Weber tech manual. It's a great source of info.

Posted by: NineOneFour Nov 7 2008, 03:37 PM

I've got the PDF version on my computer, but I haven't had much experience working with carbs. Before I've always taken it to someone to do the work, but I figured I need to learn so when we start AXing or doing track days I'll be able to take care of problems on the spot.

What I could REALLY use is a teener in the LA area that does there own carb work and syncing to help/show me what to do. I learn quicker when it's shown to me than when I read it by the manual.

Posted by: DBCooper Nov 7 2008, 04:15 PM

Find somebody, that's the best. If you can't, and carburetor guys are getting fewer and fewer, try the articles on aircooled.net, they're the best I've seen. Lots more straightforward and understandable than any manual. At www.aircooled.net in the "Technical Articles" section.

Posted by: Cap'n Krusty Nov 7 2008, 04:16 PM

Funny, carb experts prefer the synchrometer over the Uni-Syn because it causes less disruption and restriction of the air flow, giving you more accurate readings. The Cap'n

Posted by: Eric_Shea Nov 7 2008, 04:17 PM

Chinese brass counter weight stuck in the butterfly.

I'm with the cheesehead here. I think you need to adjust your idle bypass screws. Recalling from memory it's one of the first things you do. All of them should be seated. It sounds like you may only have one seated.

Loosen the lock nut and lightly seat them all... then check the flow and back the rest out to equal the cylinder with the greatest flow. Tighten the lock nut when they're equal.

Next set your mixture screws.

Posted by: Drums66 Nov 7 2008, 05:34 PM

What the hell is a carburetor? LoL

Posted by: Cap'n Krusty Nov 7 2008, 05:40 PM

Uhhhhhhhhhhh, like , wow, man .............................., you weren't around in the 60s, were you.................? Far out ...........

The Cap'n

Posted by: 9146986 Nov 7 2008, 05:47 PM

Do a search on carb tuning??

Posted by: Drums66 Nov 7 2008, 06:28 PM

Uhhhhhhhhhhh, like , wow, man .............................., you weren't around in the 60s, were you.................? Far out ...........

The Cap'n
[/quote]

Oh! that kind of carburetor.....I hit a few of those in the 70's, no but on a serious note.......I was alluding to the fact of DB's quote, technology is pretty much phasing out the carb's...no shops will desire to work on them for lack of business.
the future is FI........it is more efficient....just my opinion.

Posted by: jmill Nov 7 2008, 07:33 PM

I dont care for the fancy stuff because the only way to adjust the needle is to bust out little plastic holes. I've found that to get a good reading at higher RPMs you have to bust out so many that the idle reading doesn't register. It's funny that everyone prefers different tools to do the same job. Some do it better than others. Some claim their experts because they have a fancy tool. If you adjust the uni-syn so it reads in the lower part of the scale you'll have plenty of flow. I never liked the idea of having the carb breathe though a bunch of plastic. It seems that would clog things up worse. Maybe swallow up a little piece of garbage with a brand new engine? No thanks.

Don't bottom out the air bypass screws. Seat them gently and then set them all at one half turn out. Turn them from there and don't go over 1 1/2 turns out. Before you play around with them make sure the 2 throats closest to the linkage flow the same. If they don't your linkage is jazzed or you have to tweak the idle screw.

The initial butterfly adjustment should be .004". Set that with your idle screws. Once it's running good you can back them off to drop your idle speed down. You don't have to do this but it will run alot better at first. After doing it a few times I just make sure both sides are closed the same and open at exactly the same time.

Posted by: jmill Nov 7 2008, 07:39 PM

Set all your mixture screws out 3 turns. You set your mixture screws by ear. Spin them out slowly until the engine drops off a bit. Then spin them in slowly until it picks back up. Leave them there. If you go in too far you get a pop in the face. Back it out again and start over.

If it doesn't drop off your out too far. Spin them in until it picks up.

Posted by: Mark Henry Nov 8 2008, 08:01 AM

Sorry bud but you don't know how to use a sync.

Posted by: NineOneFour Nov 8 2008, 08:35 AM

Thanks Alf

Posted by: jmill Nov 8 2008, 03:51 PM

I'm assuming by your comment that they changed the design some in 20 years. Either that or you never check the linkage balance at higher RPM. At higher airflow it would suck the little spring loaded flapper of the old one to the max. I'll let you carb experts run with the fancy plastic stuff. I'll stick with the venturi principle of my trusty uni syn. If it's good enough for an accurate air/fuel mixture why wouldn't you trust it to sync your carbs?

Posted by: craig downs Nov 8 2008, 07:24 PM

I've used both syncs and the uni sync sucks. By the time you get adjusted to show a reading you choke alot of air going thru the carb which lowers the idle ever time you put it over the throat. Then you have the bouncing ball to try to give you a reading.

As far as the air bypasses go they should only be used to equalise the flow of the low flowing throats to the high one and thats it otherwise they should be closed. Think about it why open a air bypass if you don't need to.

Posted by: craig downs Nov 8 2008, 07:26 PM

I've used both syncs and the uni sync sucks. By the time you get adjusted to show a reading you choke alot of air going thru the carb which lowers the idle ever time you put it over the throat. Then you have the bouncing ball to try to give you a reading.


As far as the air bypasses go they should only be used to equalise the flow of the low flowing throats to the high one and thats it otherwise they should be closed. Think about it why open a air bypass if you don't need to.

Posted by: Joe Ricard Nov 8 2008, 07:45 PM

This has got to be the biggest bling leading the blind thread I have seen here in months.

Synch the carbs with the throttles off the idle stops. I prefer around 2000 RPM. adjust the linkage arms to get them the same.
then get the carbs on the idle stops and set idle equally again using the stop screws.

This is of course after you get the low flowing barrel fixed by cleaning out the IDLE JET!!!!!!!!!!

Posted by: jmill Nov 8 2008, 07:49 PM

If your idle jets are perfectly sized that would be true. If they're not you can adjust your air fuel mixture at idle with the air bypass without swapping out idle jets.

Posted by: jmill Nov 8 2008, 08:19 PM

Joe's right about the plugged idle jet. That would do it.

Posted by: Joe Ricard Nov 9 2008, 08:14 AM

There are some other things to "perfectly" :
Get a set of jet reams from CB performance
You can get your idle jets, main jets,
Main air correction, and idle air correction
as well and Accelerator jet nozzles.


Of course having a fully balanced CC'ed and equal compression ratio for each cylinder goes a long way.

My cylinders tune it to a bit closer than a BCH and you can tell it.