72 Westy, 1700 Dual Carb, Another One Won't Idle!

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wdollie6
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72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by wdollie6 » Tue Sep 22, 2015 12:46 pm

I posted on the other forums but am no longer receiving responses, more than likely my own fault as I have posted in my old thread...

Last winter I rebuilt this engine using all appropriate books, attempting to follow step by step, all went well. Several months ago started engine with no problem, then broke it in per requirements, however wouldn't idle. Didn't worry at the time but now that the restoration work on the body is complete and assembly in process am returning my focus to the engine.

Things I have done:
1. Timing was set once but very erratic so after reading on these forums that this can be caused by sticking weights in the distributor tore that apart to a deeper level and yup weights were catching. Cleaned it up lubed and it worked find, retimed and no longer an issue holding steady at the mark. At the same time rechecked the valve clearances and these were still in spec.. Also have checked the points and they are still set properly as well.

2. Carbs. were rebuilt and have been torn apart several times in an attempt to address the idle issue. Found that the drivers side carb. had very bad throttle shaft bushings which has been repaired. Also reset the fuel height in both bowls to 13mm , previously was at 16.5mm.

3. Checked for vacuum signal, as well as checking all other vacuum hoses, fittings, etc.. Didn't expect problems as everything was new. The only issue I found was that an epoxy repair that I had done to the CIS mix pipe had failed allowing air to enter. I corrected this by sleeving with an appropriate sized fuel hose and then clamped on either side of the original repair. No longer an issue, was hopeful that magically this would solve the problem, no genie in that bottle.

Over this last weekend pulled out the Amskeptics procedure again and was hopeful that I would be able to obtain an idle of any sort, not to be. One of two ways I could achieve idle, partially cover the CIS speed screw with my finger or unloosen the pilot jet. Frustrated to say the least as this was the same before I found and addressed the above issues. I have read all the posts I can find and have gone through the dual carb procedure multiple times but can't seem to find an answer. The engine runs great at higher rpms but as soon as I release the "push only here" the engine dies, does not even consider idling.

I did notice that after setting the timing again that when I achieved the 26-28 BTDC at 3300 rpm, the timing mark at idle or approximately 1000 rpm (difficult to hold because of finger on CIS intake) was actually 5-7 ATDC, that doesn't make sense as the procedure indicates it should BTDC. Any thoughts on this one, or for that matter any thoughts on how to get the idle, other than by using fingers? I am frustrated to the point where I've had to walk away vs. taking a hammer and doing something stupid...

Thanks for any help.
1972 Superbeetle Convertible
1972 Westy Bus
1972 Beetle
1970 Fastback
1966 6V Beetle with Sunroof

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satchmo
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by satchmo » Tue Sep 22, 2015 4:56 pm

If you have the stock 72 set up, then your system should look like this:

http://www.ratwell.com/technical/DualCarbs.html

Richard also has some photos of the vacuum hoses:

http://www.ratwell.com/technical/VacuumHosesCarb.html

Perhaps you have already seen those pages.

I believe all the stock dual carb engines had their idle timing set to somewhere between 7-10 degrees ATDC in order to get a lot of air moving into the central idle system. You can look up stock specs for the distributor on a 72 bus at http://www.oldvolkshome.com/ignition.htm.

My only other suggestion is to inspect and test the large cut-off solenoid on the driver side carb to make sure it is working correctly. Sometimes they stick and keep the central idle system from working. Colin mentioned something about them needing a little 'pre-load' in order to function. You will have to ask him about that.

Good luck,

Tim
By three methods we may learn wisdom:
First, by reflection, which is noblest;
second, by immitation, which is easiest;
and third, by experience, which is bitterest. -Confucius

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wdollie6
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by wdollie6 » Wed Sep 23, 2015 7:04 am

Thanks for the feedback Tim. I have reviewed both Richard's and Colin's site in detail, they have been very helpful, however still can't seem to get an idle. I will look at the other link to see what information lies there....

Wayne
1972 Superbeetle Convertible
1972 Westy Bus
1972 Beetle
1970 Fastback
1966 6V Beetle with Sunroof

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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by Amskeptic » Thu Sep 24, 2015 4:45 am

wdollie6 wrote:Thanks for the feedback Tim. I have reviewed both Richard's and Colin's site in detail, they have been very helpful, however still can't seem to get an idle. I will look at the other link to see what information lies there....

Wayne
Where are you located, Wayne?

I promise that your issue is simple but possibly well-hidden.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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wdollie6
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by wdollie6 » Thu Sep 24, 2015 11:41 am

Colin, upstate NY to be specific Delhi NY, northern Catskills. I would agree with your diagnosis, but sometimes frustration rules, unfortunately. Seems like I was closing in on solutions only to try them and the problem remain.

Wayne
1972 Superbeetle Convertible
1972 Westy Bus
1972 Beetle
1970 Fastback
1966 6V Beetle with Sunroof

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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by Amskeptic » Sat Sep 26, 2015 6:50 am

wdollie6 wrote:Colin, upstate NY to be specific Delhi NY, northern Catskills. I would agree with your diagnosis, but sometimes frustration rules, unfortunately. Seems like I was closing in on solutions only to try them and the problem remain.

Wayne
I could have visited you on September 5th as I left Woodstock . . .

Check/set timing to 28* BTDC (no hoses on distributor) at 3,200 rpm and forget about it.

Turn on ignition only. Let me know if all three solenoids click when you pull terminals off. The central idling solenoid is different than the others, it is merely a plunger. It has to retract. You stated that you put your finger over the air inlet of the central idling circuit. You do feel vacuum, you do hear a serious sucking sound of air rushing in, yes?
If not, verify that the plunger retracts with ignition on. It needs a ground path, no rubber sealing washer here, maybe a copper or steel washer if necessary, but be aware that the plunger has to be slightly pushed in as the solenoid seats. This is critical. It is called "pre-load" and people sometimes have too big of a sealing washer to let the plunger get pushed in the necessary 1/32-1/16". The solenoid will not retract properly under electrical stimulation if this preload is not there.
If the central idling circuit plunger retracts with a robust click, you should hear a good sucking sound, but the engine will not idle if that air does not have the fuel it needs to run the engine. The little screw on the other side of the air intake must allow enough fuel to mix with the sucking air to run the engine.
If necessary, crank out (CCW) the little screw willy-nilly to see if the engine will hold an idle. If you achieve an idle (it may be fast, we don't care), let me know.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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wdollie6
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by wdollie6 » Mon Sep 28, 2015 9:34 am

Colin,

You're right Woodstock is fairly close, a beautiful drive from their to Delhi...

All three of the solenoids are clicking and yes the central idling system definitely has vacuum, as you open up the screw the noise increases, and have good vacuum with hose off entirely. By the way I could get idle by covering up 2/3rds of the CIS intake but to some degree achieved the same result by cracking the carb. Solenoids... hmm. I have no seal washer (no leaks), originally had a small copper but pulled it out as thought it might be one of the problems.

I am on the road for the next 1.5 weeks so will try to "Willy-Nilly" the little screw when I return, will advise of results. The good news is that the engine is easy to work on now as it is still on my "test stand" and will remain there as I continue to reassemble the bus which I hope to have mostly completed by end October.

Thanks for the advice, will let you know results. Might have to schedule a 2016 visit???

Wayne
1972 Superbeetle Convertible
1972 Westy Bus
1972 Beetle
1970 Fastback
1966 6V Beetle with Sunroof

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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by Amskeptic » Mon Oct 12, 2015 6:10 pm

wdollie6 wrote: will let you know results. Might have to schedule a 2016 visit???
Wayne
I'll be here. There. Visiting from 10 to 206 to 30? to 28, left to you, right to Woodstock.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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wdollie6
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by wdollie6 » Tue Oct 20, 2015 1:48 pm

Finally back home with no commitments for the evening will reenergize engine and attempt to get idle one last time. Prior to that will adjust valves, points and then timing one more time to ensure that no other issue can be piling on... I will recheck carb float levels as well as the first time I checked the fuel level was closer to 17 mm than the spec., although not sure how much adjustment I have remaining.

Wayne
1972 Superbeetle Convertible
1972 Westy Bus
1972 Beetle
1970 Fastback
1966 6V Beetle with Sunroof

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wdollie6
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by wdollie6 » Thu Oct 22, 2015 10:18 am

So finally last night spent some time with the engine for the first time in weeks, deciding to work on carbs first. Since I had previously adjusted float level on drivers side carb. focused on opposite which was fortuitous because I found out that the bushings I thought were in good shape were actually not so good, the shaft didn't move much but it seemed stiffer, didn't rotate as well. Sprayed with carb cleaner and surprise, surprise I had leakage at shaft to bushing on both sides of the carb, even though it felt tight. Tore it apart and found that the shaft itself has corrosion on it which made it appear tight, once cleaned with a soft wire brush it was very sloppy indeed. Should have pulled this out when I rebuilt the carbs but it felt tight... Good news is that I had my machinists make me two sets of bushing so tonight will install, then begin the process of valves, points, timing before once again trying to get to the mysterious and elusive entity called idle.

Good news is I am learning, bad news is I should have learned 38 years ago when I had my first beetle, 63' 6 volt, great car, although my current '66 favorably compares.
1972 Superbeetle Convertible
1972 Westy Bus
1972 Beetle
1970 Fastback
1966 6V Beetle with Sunroof

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Amskeptic
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by Amskeptic » Thu Oct 22, 2015 6:39 pm

wdollie6 wrote:Finally back home with no commitments for the evening will reenergize engine and attempt to get idle one last time. Prior to that will adjust valves, points and then timing one more time to ensure that no other issue can be piling on... I will recheck carb float levels as well as the first time I checked the fuel level was closer to 17 mm than the spec., although not sure how much adjustment I have remaining.

Wayne
I think you want 13mm with the PDSIT carbs. Be accurate! The carb bases are three degrees tilted forward (i.e. towards the float chamber drain bolts). You MUST have the carbs tilted 3* forward for the fuel level to be precisely level with the top surface of the carburetor.
youthinkI'mkidding,
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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wdollie6
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by wdollie6 » Fri Oct 23, 2015 5:31 am

Colin, thanks. I had read elsewhere that the bases had to be level to accurately measure the depth. First devise a way to measure 3 deg. then correct on passenger side carb. and go back to drivers side and do the same... Then, and only then will I go through all of the other steps as I don't want to have doubts when I fire her back up. I have high hopes that all of these adjustments, corrections ofrookie mistakes, etc. will yield an engine that purrs at idle.

Wayne
1972 Superbeetle Convertible
1972 Westy Bus
1972 Beetle
1970 Fastback
1966 6V Beetle with Sunroof

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Amskeptic
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by Amskeptic » Fri Oct 23, 2015 7:14 pm

wdollie6 wrote:Colin, thanks. I had read elsewhere that the bases had to be level to accurately measure the depth.
I have no doubt at all that you read exactly that.

Now go make the top edge of the float chamber exactly level, side to side and front to rear, with a spirit level and look at the base. It will have more space between it and the table surface at the rear. Might be hard to tell with those studs sticking down.
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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wdollie6
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by wdollie6 » Tue Oct 27, 2015 8:11 am

So... Rebushed the passenger carb followed by a thorough cleaning and verification that all ports were clear, then reassemble. Adjusted float levels per above, adjusted cold valves (only one needed a slight tweak), set point gap, and then reset timing (hoses off, 3400rpm), and disappointed to state that the idle problem continued unabated... scream, pull hair out, reach for the hammer! Engine sounds great at higher rpms and on choke (at least to me) but will not run at anywhere near idle without partially covering CIS intake. Along the way I discovered that not putting the valve cover back on properly is not supportive of a smoke free environment in the garage...

As suggested I willy nillied the idle mix screw with no effect which I find strange, why, why, why? What am I missing? As you suggested it is probably something very simple but what? A mystery for sure... Meanwhile I continue to assemble the rest of 'Fat Boy' at my metal mans garage as I don't want to put the engine in until running somewhat normally. I have come to the conclusion that my metal/body guy is not that good, especially the closer I look at things, a little disappointed, maybe a lot. Oh well on we go.

Again thanks for the continued help, let me know when we need to look at other options. With winter setting in will more than likely have to wait until spring anyway...
1972 Superbeetle Convertible
1972 Westy Bus
1972 Beetle
1970 Fastback
1966 6V Beetle with Sunroof

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Amskeptic
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Re: 72 Westy, 1700 Dual Carb, Another One Won't Idle!

Post by Amskeptic » Tue Oct 27, 2015 1:03 pm

wdollie6 wrote:SI willy nillied the idle mix screw with no effect which I find strange, why, why, why?

Exactly. Remove left carb top. It will have the Central Idling Mixture Emulsion Tube sticking down, that annoying brass tube that has to be tickled around the cut-out on the carb top gasket.

I think that tube may have a crack in it, if it is not plugged up. Look closely. Blow through the hole where the mixture screw used to reside and feel for air coming out at the bottom of that tube where it normally sits in the fuel.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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