1978 Goldwing low speed miss

[redglbx]

[OhioBill]

Here is an update. I overhauled the carbs using a randakk kit (getting pretty pricey). No difference. I then soldered up some old slow air jets and drilled them at .042. This mod made no real effect on my miss problem either. Put the original jets back in. Out of frustration I reset the timing from 5° btdc to 8°bfdc. It ran a little smoother. I think I am getting ignition varation due to wear and tolerance in the cam drive.
After reading all the comments I check the slow speed needle jets by turning them close, one at a time. Carbs 1 & 2 made no difference when I closed them. 3&4 stalled the motor when they were closed. Off with the carbs to clean the slow speed circuits. While they were out I checked all the jets and cleaned them. I also checked the infamous 120 and 60 air jets for proper location. Curious thing, when I removed the kidney shaped cover one of the kidney shaped gaskets had split and another was mis-shaped. I reinstalled all four kidney gaskets with some old ones that I had saved. Reinstalled the carb set and still some missing. Checked the slow speed needles by closing one at a time. Carb 1 still not effect on needle position. Carbs 2,3 &4 responded to the closing procedure by stalling the motor. I'll be pulling the carbs again. Is there a procedure for checking the slow speed circuit other than squirting cleaner through all the passages?

[Whiskerfish]

Sounds like you are narrowing it down! Ideally a single jet closed will result in a a drop of 50 -100 rpm and if the other 3 are working properly the engine will continue to run. The regular tach does not always show the difference but a close listen will. Spray cleaner and 120 psi are what I use. Just make sure none of the other passages are closed off like having the bowls on or such. Do not hit the fuel passage with 120 psi unless all the carbs are removed from the plenum. These seals do not hold up to 120 psi and you could easily create more issues for yourself.

[OhioBill]

https://photos.app.goo.gl/DMsFKjQiqEATGCAo8[/Video]

Further updates to my problem. The posting is my 78 with a Colortune installed. The #2 cylinder is showing yellow during ignition while #4 cylinder is consistent blue ignition. I can completely remove the idle needle and there is not effect on the idle. I have removed and cleaned the carbs so many times that I have lost count but the last two times I was focused on the #2 carb. I sprayed the passageways with carb cleaner and blew out the passageways with 90 psi air. The cleaner came thru all the passageways much like the other three carbs. The idle jet under the rubber plug is clear. Any insights or thoughts would be welcome. My only other thought was to suspend the carb body in my ultrasonic cleaner so that the shaft felts are above the cleaning solution. Any thoughts?

[gltriker]

Bill,
Take a look at the attached link with photos of the 'idle' circuit Idle Discharge Port Jet.

(Notice how the fuel bowl gasket is distinctly compressed onto the raised perimeter of air/fuel pilot 'idle' circuitry.)

You have completely removed the pilot air/fuel mixture screw and determined that action makes no difference in the way that carburetor reacts.

Very Carefully, with the float bowl securely fastened in its place on the carburetor body, with very good eye protection in place,
Observe where the aerosol spray is being discharged from the carburetor throat.
Perhaps the brass Idle Discharge Port Jet is plugged.

Check the tip of the pilot air/fuel mixture screw for damage, too.

viewtopic.php?p=826017#p826017

Perhaps you may be overly concerned about the felt throttle shaft washers' designated purpose.
Soaking in a liquid is not harmful as compared to blasting them with pressurized air
.
Their main purpose is to prevent incidental contamination and throttle shaft/bore wear with airborne abrasive, not as an air tight throttle shaft sealing component.

A very common application for that purpose is a lawnmower carburetor's external throttle shaft environmental dust seal.
.

[gltriker]

After I resized the slow air jets on my engine's carburetors, I discovered that same small diameter #62 micro drill bit's dull end is a good tool to plunge into the open end of the Idle Discharge Port Jet, too.
I detected a smaller diameter depression exists at the far end (beyond the exposed discharge orifice in the carburetor throat ) that can trap dried fuel that brake spray and compressed air may not remove.

Note: I will advise you to read, top to bottom
, that entire linked to page.
There are several additional links within that series of posts that will take you to additional idle circuit metering components photographic examples of, when newly manufactured appearances.

[Whiskerfish]

You said you changed the coils right? Did that include the plug caps? At this point I would want to verify the spark again. Quick and easy check is to swap the plugs and the wires left and right. Swap # 1 and 2 and then # 3 and 4 then see if your problem stays or moves.

[OhioBill]

Will do, Whiskerfish

[OhioBill]

Steve
I had a complete set of Dyna coils,wires and caps installed when I started chasing this problem. Now I have a complete set of stock coils, wires and caps installed. The resistance checked out at 14.4k ojhms.

[redglbx]

Bill, you want less than 5k ohms across just the plug caps, I’m assuming your check was across it all ?

Many years ago when I was trying to resurrect my 80CBX I walls struggling much the same as you, theCBX guru at that time was a very good guy by the name of Tim Ware who told me that when you think you have the idle circuit clean go back & clean it again because it really isn’t, smart man ! The CBX uses carbs very similar to the GL1100’s and in my opinion easier to verify idle circuit operation. If you sand your carb cleaner straw to a point you should be able to insert it into the idle jet (protect your eyes !) and have it spray out of the discharge in the carb bore.

Myself ,fyi, many of the weird problems I’ve experienced have traced back to spark plug cap issues, mostly higher than spec resistance, again the cap should check at less than 5k. Keep at it, you’ll get it ! Lots of good help available here.

[Whiskerfish]

14.4 is dead on spec. for cap to cap

Okay double check Belt alignment? One tooth off will run but not well.

[gltriker]

https://www.randakksblog.com/coil-testi ... /#more-236

[redglbx]

Thanks Steve, I forgot about that !

[OhioBill]

I FINALLY got rid of the low speed stumble. My 78 now pulls away smoothly in 4th gear at a 1000 rpm. I tore the #2 carburetor down completely and cleaned it in an ultra sonic cleaner with a simple green solution. I also reinstalled my dyna coils and wires. I checked the resistance of the coils, wires and caps. One cap on the #4 wire had resistance out of Spec so I exchanged all four with. a new set that I had. I balanced the carbs and set the low speed needle at 2 turns out which is the Spec listed in the factory manual. It's the first time it has run like a 75 motor since I repurchased it. The cams and ignition and the 76 carbs really wakes the 78 up.
Thank you to all that responded and all the information shared. That is what makes this group the place to be..

[gltriker]

I FINALLY got rid of the low speed stumble. My 78 now pulls away smoothly in 4th gear at a 1000 rpm. I tore the #2 carburetor down completely and cleaned it in an ultra sonic cleaner with a simple green solution. I also reinstalled my dyna coils and wires. I checked the resistance of the coils, wires and caps. One cap on the #4 wire had resistance out of Spec so I exchanged all four with. a new set that I had. I balanced the carbs and set the low speed needle at 2 turns out which is the Spec listed in the factory manual. It's the first time it has run like a 75 motor since I repurchased it. The cams and ignition and the 76 carbs really wakes the 78 up.
Thank you to all that responded and all the information shared. That is what makes this group the place to be..

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