Engine idle speed synchronization vacuum numbers

[Sidecar Bob]

87 octane should be fine for the 'Wing. Anything higher is just burning more money for less energy.

[gltriker]

Yes. Bob. True.

Trike's engine has always been satisfied with fresh 87 octane gasoline. 31,000 miles satisfied.

-- to be continued

[gltriker]

Wow, a month has come and gone since I last posted in this topic!

snip-
If I understand the "stronger signal" benefits to carburetion ( when GL1000 valve lash is increased to 0.006" ) it is best identified by the vacuum measured during the carburetors' idle synchronization procedure, that will display at a higher value on the vacuum measuring device/s?

snip- Mike Nixon's reply to my query
Oh, one more thing. I would not expect to see a change in manometer readings when running 0.006" clearance, though to be honest I haven't looked for them, so I really don't know. There you're talking intake vacuum, so...I don't know. . Carburetion richens with compression increase for the same reason it leans with compression loss: venturi signal.
This isn't exactly the same as vacuum.

Mike's reply was never followed up by me and vacuum testing manometer to determine Yes or No, a measurable change in idle speed synchronized intake manifold vacuum will or won't occur.

And, NO I haven't, yet.

[mikenixon]

snip-
If I understand the "stronger signal" benefits to carburetion ( when GL1000 valve lash is increased to 0.006" ) it is best identified by the vacuum measured during the carburetors' idle synchronization procedure, that will display at a higher value on the vacuum measuring device/s?

snip- Mike Nixon's reply to my query
Oh, one more thing. I would not expect to see a change in manometer readings when running 0.006" clearance, though to be honest I haven't looked for them, so I really don't know. There you're talking intake vacuum, so...I don't know. . Carburetion richens with compression increase for the same reason it leans with compression loss: venturi signal. This isn't exactly the same as vacuum.

Mike's reply was never followed up by me and vacuum testing manometer to determine Yes or No, a measurable change in idle speed synchronized intake manifold vacuum does occur.

Actually, I need to correct what I said about richness and leanness, and possibly comment on vacuum. Compression variance does affect rich/lean but not as many suppose (and not as I mistakenly proposed) due to signal (vacuum) changes but rather due to changes in combustion efficiency. More compression results in higher fuel efficiency which treats the carburetor as if it is richer. The reverse is also true. Low compression lowers combustion efficience which makes the engine act as if it isn't getting enough fuel, i.e. it's effectively leaner. This latter fact is why so many vintage bikes run less well than they should. On the subject of whether increasing valve clearance should result in a higher intake vacuum at idle (here the car guys who have a lot more experience using vacuum tests for diagnostics have developed an impressive range of conclusions are are thus way ahead of us), it stands to reason if it increases compression it ought to affect intake vacuum. I wouldn't know however. I'll take your word for it. The most important fact in all of this is what valve clearance is for, which is not tuning. See my article on this. Valve clearance is discussed about one-fourth way into the article.

https://www.motorcycleproject.com/text/cam_facts.html

[gltriker]

Thanks Mike

[gltriker]

...

[gltriker]

POST #37

I Finally convinced myself yesterday evening was a good time to put gasoline in trike's fuel tank and start the engine, after having spent a lot of hours helping other folks," get their motors running."
I really enjoy doing that with/ for other folks, too.
My interest in working on my bike wanes during the summer. Seems like I get toooooo interested in components and study and photograph things I want to remember. "Keep your eyes and ears open and you'll learn something new, everyday." That one thing you casually observed one day will eventually be the clue you need to solve a problem you didn't know existed, in this case from 6 years ago. a Carburetor problem thing. There were several obvious clues a person/persons who wore boxing gloves had their hands on a set of '76 LTD carburetors I acquired for the cost of just postage to send them to me. Might have been $30.

I purchased the '76 LTD spec. carburetors circa August, 2017, -just a week or so before the NGW Ivy Lea get together in Canada,- which seemingly worked well after I disassembled and replaced all the odd ball "carb kit" brass components with the correct Keihin parts I had removed from the 1976 spec. carburetors that were on my '75 when I became its owner. Of course, a Randakks GL1000 carb refurbish kit was installed, too.
Although I had no experience with a stock GL1000 ( much less, a stock 2 wheeled GL1000 ) I felt it was a very good running engine after all the work and attention I had given to the entire fuel delivery system ( fuel tank to carburetors) and ignition system (Dyna S , Dyna ignition coils and copper strand spark plug wires, SPST 12v relay, etc,) I will explain in greater detail later in this thread how I have discovered an, almost a EUREKA revelation. I have to remove the carburetors again to verify what I believe, now, was responsible, back in May, 2020, for the degrading engine performance that I had mainly blamed on a right side H-D catalyst element muffler.

After running another carburetors' synchronizing session on my trike last night, I was trying to understand WHY the #2 and #4 carburetors could be quite easily synchronized. They soon averaged between 5-7 inches/mercury with twitchy vacuum gauge needles, at 900ish rpms. Important fact: all valves' lash clearance is set at 0.004 " presently. AND the pilot air/fuel screws are set at 3 full turns out from lightly seated.

The #3 cylinder vacuum gauge reading was an eye opener in comparison to the #1 cylinder gauge reading. As I recall 12in/hg vs. 8in/hg. Surprisingly, the engine speed wasn't running away and the engine curb idle speed screw wasn't touching its stop boss. I could push the head of the idle speed screw and/or utilize the throttle's push close feature to bring the engine down to below 1000rpm and the engine never threatened to stop running.
Quite similar to what I was blaming on "crap" gasoline, when I started this Topic, 4 months ago.

After puzzling how and why such behaviors were happening it suddenly came to my attention, after inadvertently touching the back of my hand against the very hot #3 intake manifold when pushing the curb idle screw closed . I hadn't retightened all 4 very loose intake manifold band clamps. Now is the perfect time to crank 'em down!
Yes, I then had to stabilize the very low curb idle speed (stalling engine) with turning the idle screw, "in", to touch its boss. The #2 and #4 carburetors' synchronization vacuum numbers didn't change more than an inch/mercury and remained very stable as I tried to, unsuccessfully , balance #1 and #3. In fact when I got them close around 9-10 in/hg the #1 and #3 synchronizer screw had fully compressed the tiny coil spring between the synchronizer links.
*Yes, the 2 special washers were positioned correctly on either side of the "fork'.
*Yes, I was shutting off the engine and snapping the throttle open and shut. The baby directly across the road was most likely sleeping.

I can't recall where the #4 and #3 , left and right banks' synchronizer screw was positioned when my eyes and brain were done for the day. I know its setting nut is still in place though.

Here's how I initially set up my 4 vacuum gauges synchronizing panel Thurs, 9/28/2023 5ish pm

viewtopic.php?p=820664#p820664

- to be continued

[redglbx]

Cliff, let me ask. Have you checked the gauge calibration ? Your gauges in your picture look the same as mine and on mine I connect all the vacuum hoses to a common source and then use my Mity-Vac as a common vacuum source and all the gauges should read exactly the same. There is a calibration screw on the front of each gauge so they can be adjusted. The actual number doesn’t really matter but they should all read exactly the same.

Once I think I have them all the same I release the Mity-Vac and then re-apply vacuum and they should all come back and read the same.

[gltriker]

Hey there red!
Yes I am familiar with the gauge needle calibration screw on the face of each vacuum gauge. I also own and often use my Mity Vac vacuum pump tool.
-

20230930_104743.jpg

I believe I have finally determined WHY and How the number 3 carburetor has presented the extremely large vacuum in/hg reading when I first time attempted to check the synchronization of these 1976 LTD carburetors back in May of this year and again this past Thursday evening
.
Have to get something straight for folks getting familiar with 4 cylinder GL carburetors' dynamic (running engine) vacuum synchronization. For clarity purposes if a person would suspect my issue is related to a misconception I've read occasionally.
#3 carburetor isn't a "Master" carburetor. It is a very close friend with #1 carburetor . A pair from the Right Bank.
#2 and #4 carburetors are very close friends. A pair from the Left Bank. If there was a "Master" carburetor in the group of 4 carburetors I would call #4 carburetor, The Equalizer. Harmony is its claim to fame?

I will characterize #3 carburetor , though, as the master estrangulador. (choke

The choke cable linkages all move off the orders of the #3 choke shaft movements.

That will make better sense as I advance further along in my investigation WHY the #3 vacuum synchronization gauge is presenting far greater in/hg readings in comparison to its Right Bank neighbor, #1, and their- over the crankcase- Left Bank mates , carburetors #2 and #4


re: the May synch session...remember how firmly I expressed my personal distaste of a bench synch .

I have to take several more pictures of throttle linkage parts that I had to swap over from the plain old 1976 GL1000 carburetor '"rack" onto the 1976 LTD carburetor "rack" back 6 years ago - 2017- just after receiving them.
This is a story beginning with mentally retained 'photographs' of bear cub with boxing gloves type grievously mishandling of these carburetors stored in my aging memory starting 6 years ago.
And will be ready to offer up more photographs , I'd taken of these carburetors again, for your collective entertainment. Not right now though.

-to be continued

[gltriker]

I pulled trike's '76 LTD carburetors' 'rack' yesterday, and have determined my suspected carburetor synchronizing issue was wrongly contrived. All 4 choke shutters are indeed flat. I confirmed, again, the #1 and #3 synchronizer link 2 special washers placements are correct on either side of the fork. Although I reported its compression spring was fully collapsed, I found yesterday it wasn't. There was an additional turn of the synch screw available that brought both throttle shutters equally closed in their respective carburetor throats.
Too much back story observations, suspicions, etc., to present into this thread. My frustration with fuel quality, having a bench synch suspicion eating at me, confusion that I could turn synchronizer screws so far without seriously disrupting the engine behaviors, and questioning if my examination of the carburetors more than 2 1/2 years ago was contributing to this conundrum in the process of reawakening the bike's engine.

I found several photographs of this carburetor rack on my old cell phone, dating back to October-November 2020, that showed me a loose choke shutter screw. It was located, though, on the number 4 carburetor position.

20201011_171347 (2) #4 CARBURETOR - LOOSE CHOKE SHUTTER SCREW.jpg

The #1 and #3 carburetors synchronizer link compression spring was seemingly collapsed in what I would consider excessive compared to the general appearance of the #2 to #4 synchronizer , and the #4 to #3 synchronizer link.
I thought it may be helpful to move the special washer closest to the compression spring out of that space but the nut won't spin off beyond the adjuster screw slot.

20231001_195156.jpg

I did find in one of those aforementioned 2020 photographs the #1 to #3 synch link. I'm frustrated that my old cell phone is no longer sharing/sending these old photos to my email as they had been until earlier this year. If I had them available via email I would be able to enlarge the photos and study the details better.

I know I had successfully synchronized these LTD carburetors in 2017. I had to perform that session because the #2 to #4 synchronizer link fork had been twisted and the screw damaged, too.

Anyways... I will reassemble the 'rack' now, reinstall them onto the engine and run a synchronizing session again.

(I should have already been doing that work today, but got caught up with updating this Topic, instead

[gltriker]

snip-
I have to take several more pictures of throttle linkage parts that I had to swap over from the plain old 1976 GL1000 carburetor '"rack" onto the 1976 LTD carburetor "rack" back 6 years ago - 2017- just after receiving them.
This is a story beginning with mentally retained 'photographs' of bear cub with boxing gloves type grievously mishandling of these carburetors stored in my aging memory starting 6 years ago.

-to be continued

the #2 to #4 carburetors' synchronizer link 'fork' was twisted out of alignment with the adjuster screw, compression spring and both flat washers. I was successful to twist the 'fork' back into correct alignment , without damaging the throttle shaft, and borrowed the adjuster screw from the retired 1976 GL1000 'rack' Yes, the 2017 synch session, afterwards, was successful

moving along...

https://www.wingovations.com/synchronis ... rburettors
Old Fogey pointed out the quadrant has several areas to check . I listened in 2017, and although the LTD throttle links are attractive, I pro-actively swapped out the '76 LTD carburetors 'rack' quadrant and both throttle links.( links-arms all same part

20230930_185750 (2).jpg

-

20231001_155716.jpg

[gltriker]

Post#42 Weds., October 4th 2023


If you have been following my long winded reawakening of my 1975 GL1000 thread, with '76 LTD carburetors I had installed around August, 2017, I was troubled with the last carburetors dynamic synchronizing session ( Friday, Sept.29th) because the #3 carburetor vacuum gauge was displaying very big vacuum numbers ~12in/hg. I found the #1 to #3 synchronizer link adjusting screw was bringing the #1 carburetor's initial vacuum reading of~8in/hg closer to #3's , but the small compression spring was completely compressed into a coil on coil bind. hmmmm... what's going on?

Although I've spoken of the LTD 'rack' #2 and #4 synchronizer link's 'fork' was discovered to be twisted out of shape-I believe to idiotically reposition the special washers on either side of the 'fork' - at some time before I purchased the "rack" in August 2017.
I was successful to bend the 'fork' back where I thought it had been at the time of manufacture. ViseGrips bending effort was involved. I thought the throttle shaft would surely bend, if not break off, altogether. It didn't, and I was very fortunate to only have to replace the badly bent adjuster screw. Of course I needed to readjust the 'repaired' #2 to #4 synchronizer link and performed a dynamic session with my 4 vacuum gauges panel. The left bank carburetors' balance adjustment was accomplished without incident. I don't recall having to make any readjustments on the right bank, #1 and #3 carburetors, though.

Where I'm going with this is, I finally figured out, today, the #1 to #3 synchronizer link 'fork' and its complementing screw adjusting bracket had received the same idiotic short cut treatment. That meant I had to put the ViseGrips to work on both carburetor's throttle shaft synchronizer link segments this afternoon. The ViseGrips performed flawlessly. The throttle shafts are not damaged. I have confidence the #1 and #3 carburetors will now synchronize, correctly.

20231003_162724.jpg

If a fellow is hesitating to use this miraculous synchronizer linkage "fix" because they worry a little tweak of that 'fork' might damage the carburetor throttle shaft,https://ngwclub.com/forum/viewtopic.php?f=1&t=61242 from my experiences with man handling my LTD spec carburetors twisted synchronizer link brackets with ViseGrips I would heartily recommend you do the minor tweak to "fix" your engine's "Mysterious Honda High Idle Problem", too.

20231003_163552.jpg

and a 12 seconds video

20231003_163652.mp4

[gltriker]

Update...
Although I felt really pleased for eventually discovering, and subsequently correcting the twisted out of shape #1 and #3 carburetors synchronizer linkage components as I had detailed in Post#42, Wednesday, October 4th, trike and I both had our first time ever gasoline fire injuries on the afternoon of Friday, October 6th.
Our unattached 2 car garage was barely touched. The very obvious initial visual witness to a fire event is the melted diffuser drooping off the LED light fixture hanging almost centered at 8 feet above trike. Slight charring of the 2X4 rafter the fixture is hanging from, too.
Trike's rear axle is solidly planted elevated on two jack stands. The front tire was lifted off the garage floor with my floor jack positioned under the engine crankcase. Makes it much easier for me to sit alongside trike on my 4 wheels battery powered mobility scooter, with its seat turned 90 degrees towards the bike, and see what I need to see. Solid. Won't move when I accidentally run into any of the trike's 3 tires with my mobility scooter.

The fiberglass "tins" had all been removed about 2 1/2 years ago. the complete front brakes' system and front fender had recently been removed, the front fairing and windshield had been removed several years ago. PHEW!
No, the corrected synchronizer linkages carburetors 'rack', air filter assembly and shelter frame assembly had not been re-installed yet. DOUBLE PHEW!!

I have been able to start and run the engine, with the shelter frame completely removed, for at least 3 carburetor synchronizing sessions since I started this Topic in May of this year by simply plugging a used '75-'77 fuse box assembly into the bike's wiring harness and it just hangs free off the harness. Just the nuts... maybe too easy, though.
I had performed individual cranking cylinder compression tests, several different times, at 0.004" valve lash clearance and at 0.006" valve lash clearance; each time with a proper 12mm screw-in Snap-On compression tester hose assembly AND the jackleg 14mm tester hose to 12mm screw on adaptor. (yes, it DOES make a difference!)
anyways...
During those multiples of compression testing sessions scattered over several months, the fuel tank was empty and the Engine Control Switch (kill switch) always turned to one of the OFF positions .
Cranking the engine over to check for ignition potential at all 4 spark plug wire terminals, gathered together near the number one cylinder head intake port, was very easy.
It's potentially extremely dangerous, though, if you don't remember the fuel petcock valve was left in the Reserve position with maybe 2 quarts of gasoline still remaining in the fuel tank after the last synchronization session . The carburetors hadn't been reinstalled yet. The mechanical fuel pump outlet hose barb fitting was wide open.
let's back up here...
Back in May, when I started this Topic, I needed new fuel hose sections to begin the reawakening process. I had been curious about the air in the fuel filter and air bubbles in the fuel lines conundrum flap, and had installed genuine yellow TYGON fuel hose and a new transparent fuel filter. With proper fuel line clamping practices and an efficiently operating mechanical fuel pump there was no agitating of fuel back and forth as had been worried to death about in another member's topic earlier this year.
In fact, there was no apparent fuel movement in the almost transparent fuel pump outlet Tygon fuel hose, with even tiny bubbles moving into the "rack" 's inlet fuel barb fitting, after the 4 fuel bowls are completely filled to proper levels. Moving on...
I was entirely unprepared Oct. 6th to discover how quickly the 2ish quarts of gasoline in the fuel tank was drawn into the filter and fuel pump after maybe 6 cranking revolutions of the engine while arbitrarily checking all 4 grouped together spark plug wires for sparkles.
The ensuing gasoline fire started on top of the engine. I couldn't extinguish the initially small fire, which is located so close to the front of the fuel tank, its internal pressure began to grow as the tank was heated and gasoline was forced through the fuel petcock Reserve supply circuit, towards and through the wide open mechanical fuel pump outlet. Right in front of me. I yelled for my wife. She heard me, assessed the situation, ran back out the side door and came running back into the garage with 911 on the phone in one hand, and a quickly turned on garden hose in the other after having seen me unable to drive the aforementioned 4 wheels battery powered mobility scooter forward to get away from the fire.
While she was gone, I did get the scooter to move me forward away from the fire. Patricia finally handed over the spray nozzle and I was fortunate to extinguish the gasoline fire in I'd guess 20 seconds. Just A few minutes before the fire trucks roared up to the front of our home. Fire out. Nothing smoldering. I got an EMT ambulance ride to a local ER.

The non-contact burns to the outside of my left forearm and elbow area, the outside of my left thigh and calf, and upper left side of my face were diagnosed as second degree burns, and treated accordingly with some debriding of loose skin on my left thigh and calf and application of various layers of special materials I can't remember the names of. My facial burns were treated with a continuous smeared on application of bacitracin zinc, only.
The burns were not considered bad enough to admit me to the hospital that night and I was discharged to go home after the second year Burn surgeon had conferred with his boss for the official opinion. A week later (10/13) I kept an appointment for follow-up at the hospital's Burn Clinic. When the left arm and leg bandages were removed, the 2cd degree burns had converted to 3rd degree burns and I was admitted to their Burn Ward ICU to receive skin graft surgery, Monday 10/16. I was discharged from the hospital Friday 10/20, and my wife was instructed how to change the dressings every 24 hours. She performed the daily task Very Well!
We returned to the out-patient hospital Burn Clinic Thursday 10/26 for a follow-up.
The physicians' inspections of the post skin graft surgery burned areas on my left leg and left arm are healing very well. No more daily dressing changes are required. Weekly now, unless liquid discharges show up through the kling wrap and bandnet. Gauze sheet changes are no longer required. My forehead burn blisters were almost completely healed after the first week, when I was admitted to the Burn Ward.
Our next follow-up appointment is scheduled two weeks from yesterday.
When we arrived home, I stayed in the garage and started assessing the extent of fire damage. Patricia wasn't happy.

I knew several hours after arriving at the hospital ER , water had most certainly entered the wide open intake ports and spark plug holes while I was extinguishing the gasoline fire with the garden hose. That weighed heavily on my mind. A very good engine was being injured, internally. I determined yesterday only one cylinder had retained water because its exhaust valve was closed. Either or both #2 and #4 cylinders' header had water accumulated that I heard gurgling while I was turning the crankshaft with the kick start lever. Before dropping the exhaust header off the left cylinder head , I had jacked up the front of the trike and water was draining past the header outlet to exhaust pipe connection. Pro actively, my
wife had sprayed almost a full aerosol can of WD40 into the 4 spark plug holes as I had instructed her to do one day after I was first burned.

I will eventually heal from the 3rd degree burns AND freekin' touchy skin graft donor areas around the rear of my left thigh. No elbow or knee joint burn injury was suffered and normal range of motion in my arm and leg will not be a future problem.


Trike requires mainly extensive wiring harness attention and other components that were melted and destroyed in the fire.

I will post pictures of the trike's fire damage in my, "Maybe I'll call it Threedom" topic.

https://ngwclub.com/forum/viewtopic.php ... 71#p821171

[Sidecar Bob]

Gasoline is such a familiar substance that we tend to become complacent about it and don't think about taking all the precautions we should. I've been at least as guilty of that as you, of not more; I've just been a bit more lucky.

Take it easy and do what the docs and therapists tell you to and you'll be back working on it again soon, perhaps wiser and more careful.
As we all should be after reading this.

[CYBORG]

a tough leason we all can learn from. Get well my friend The bike will wait until you do