Author Topic: No Combustion  (Read 1270 times)

Offline RFH87_Connie

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Re: No Combustion
« Reply #15 on: April 05, 2019, 01:27:02 pm »
Here is a a pic I saved from someone else in the past.  I think the port should be open unless it is related to the pump diaphragm on the carb body's side (I can't remember).  Maybe poking with fishing line a carb cleaner will free it up?
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Offline RFH87_Connie

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Re: No Combustion
« Reply #16 on: April 05, 2019, 01:31:09 pm »
One more pic that may help for clarity.
“I can truly say I had rather be at home at Mount Vernon with a friend or two about me, than to be attended at the seat of government by the officers of State and the representatives of every power of Europe.” - George Washington

Offline bigdt73

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Re: No Combustion
« Reply #17 on: April 05, 2019, 02:00:21 pm »
Here is a a pic I saved from someone else in the past.  I think the port should be open unless it is related to the pump diaphragm on the carb body's side (I can't remember).  Maybe poking with fishing line a carb cleaner will free it up?

I got both of them opened up so all four are clear now. I didn't know their function but I figured they needed to be clear.

Offline MAN OF BLUES

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Re: No Combustion
« Reply #18 on: April 05, 2019, 04:42:54 pm »
I got both of them opened up so all four are clear now. I didn't know their function but I figured they needed to be clear.

fuel origin/supply to the starting circuit... controlled by the Pilot Air adjustment needle screw..
did you disassemble and clean all 4 of those? Those are the ones below the pressed in "tamper" plugs...which need to be removed to access that circuit.
there is a screw with a fine tipped "needle", that meters fuel during startup, and up thru the 2500 rpm range, as the throttle plate opens, exposing the 4 holes on the engine side of each carbs "bore", to pull fuel...
if those adjustment screws were never removed, and those circuits "cleaned"... the bike will never "start and run"...
also, if they were removed, they need to be reassembled correctly, with all parts intact, the small rubber o-ring, the backing washer, and the spring, all on the adjustment needle... (items 8 thru 11 in photo) then seated "gently", and backed off 2 full turns from the seat...

30 YEARS OF KAW.....

Offline MAN OF BLUES

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Re: No Combustion
« Reply #19 on: April 05, 2019, 04:54:52 pm »
Pilot air location below...
also, spray gumout (with carbs disassembled) from the rear of the carb, thru both circuits shown in the other photo...along with that circuit you asked about... it should spray out evenly, from all of the small holes in the front bore of the carb "throat".(you will need to cover the pilot airscrew hole with your finger during that process, to allow the other circuits to be pressurized and spray seen...)

30 YEARS OF KAW.....

Offline MAN OF BLUES

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Re: No Combustion
« Reply #20 on: April 05, 2019, 05:04:18 pm »
Here is a a pic I saved from someone else in the past.  I think the port should be open unless it is related to the pump diaphragm on the carb body's side (I can't remember).  Maybe poking with fishing line a carb cleaner will free it up?

what the heck is up wit dat crazy picture?

what bike did that come from, with some crazy electrical connector on a carb????

 :popcorn: :popcorn: :yikes: :yikes:


30 YEARS OF KAW.....

Offline MAN OF BLUES

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Re: No Combustion
« Reply #21 on: April 05, 2019, 05:32:11 pm »
I set the float bowl height to 17mm per the shop manual and visually bench synced the carbs. ......

now, after explaining the pilot air circuit, and it's GREAT importance to starting the bike, and supplying fuel for IDLE, and just above...
HOW did you (explain the method) accomplish your "bench synch"?

When I instruct this process, I direct people to adjust the "idle" knob, to a point where the fixed stop on the carb casting is reached, then, I add 1 turn on the knob, just to "raise it off the positive stop".. then I proceed to adjust the individual carbs, the actual "adjusting screws", to move the throttle plates to a point where each and every carb has the "leading edge" of the throttle plate "covering" 1/2 of the forward hole in the throat... when observed, the "reflection" of the hole, on the throttle plate's bottom edge, should combine with the hole, and make a "perfect circle" in it's reflection, if it's less than that, the bike will not start, (so erring on the heavy side, and if the reflection is actually a "figure 8", it will still start... and backing off later on the knob will bring it back to the correct point) but the "circle" is what you shoot for..and all of the carbs must be equal... and this is all done as I noted before, after installing the pilot airscrews, fully, and backing them off 2 full turns.

if all that is followed, sticking a "synch gage" on the carbs is almost never needed, because they will be soooooo close just sticking the screwdriver on/against the adjusting screw will make it change...

30 YEARS OF KAW.....

Offline bigdt73

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Re: No Combustion
« Reply #22 on: April 05, 2019, 06:57:16 pm »
fuel origin/supply to the starting circuit... controlled by the Pilot Air adjustment needle screw..
did you disassemble and clean all 4 of those? Those are the ones below the pressed in "tamper" plugs...which need to be removed to access that circuit.
there is a screw with a fine tipped "needle", that meters fuel during startup, and up thru the 2500 rpm range, as the throttle plate opens, exposing the 4 holes on the engine side of each carbs "bore", to pull fuel...
if those adjustment screws were never removed, and those circuits "cleaned"... the bike will never "start and run"...
also, if they were removed, they need to be reassembled correctly, with all parts intact, the small rubber o-ring, the backing washer, and the spring, all on the adjustment needle... (items 8 thru 11 in photo) then seated "gently", and backed off 2 full turns from the seat...

Yes, I removed all the pilot needles and cleaned them thoroughly. There were no plugs in place and they had been previously turned all the way in when I first started working on the bike. After I got the bowls back from Steve I asked him how many turns out and he advised me the same as you. With this most recent dissambly I noticed one of the metal washers was missing. I have spares so I'll make sure to reassemble it per the photo you attached (Thank you!). Right now I'm at AZ bike week so the reassembly won't happen until tomorrow or Sunday. Thank you again, MOB.

Offline bigdt73

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Re: No Combustion
« Reply #23 on: April 05, 2019, 07:01:06 pm »
now, after explaining the pilot air circuit, and it's GREAT importance to starting the bike, and supplying fuel for IDLE, and just above...
HOW did you (explain the method) accomplish your "bench synch"?

When I instruct this process, I direct people to adjust the "idle" knob, to a point where the fixed stop on the carb casting is reached, then, I add 1 turn on the knob, just to "raise it off the positive stop".. then I proceed to adjust the individual carbs, the actual "adjusting screws", to move the throttle plates to a point where each and every carb has the "leading edge" of the throttle plate "covering" 1/2 of the forward hole in the throat... when observed, the "reflection" of the hole, on the throttle plate's bottom edge, should combine with the hole, and make a "perfect circle" in it's reflection, if it's less than that, the bike will not start, (so erring on the heavy side, and if the reflection is actually a "figure 8", it will still start... and backing off later on the knob will bring it back to the correct point) but the "circle" is what you shoot for..and all of the carbs must be equal... and this is all done as I noted before, after installing the pilot airscrews, fully, and backing them off 2 full turns.

if all that is followed, sticking a "synch gage" on the carbs is almost never needed, because they will be soooooo close just sticking the screwdriver on/against the adjusting screw will make it change...

My method was almost the same as you described. I will utilize your method after I reassemble the carbs to be sure it's set the way you described. Thank you.

Offline bigdt73

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Re: No Combustion
« Reply #24 on: April 08, 2019, 10:45:35 am »
Does anybody near Arizona want to buy a project? I did everything MOB suggested about bench synching the carbs after tearing the carbs apart again. I put the carbs back in the bike, hooked up the tank, and put the petcock on "prime". I see the gas flowing through the fuel line and then I see a huge puddle of gas on the floor below the bike coming from the overflow tubes...  :banghead: :banghead: :doh: :doh:


Offline MAN OF BLUES

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Re: No Combustion
« Reply #25 on: April 08, 2019, 03:03:44 pm »
when it rains, it pours... float needles...replace, and adjust levels...

start at response #13 here...

http://www.zggtr.org/index.php?topic=24023.msg299987#msg299987


30 YEARS OF KAW.....

Offline bigdt73

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Re: No Combustion
« Reply #26 on: April 08, 2019, 05:05:46 pm »
when it rains, it pours... float needles...replace, and adjust levels...

start at response #13 here...

http://www.zggtr.org/index.php?topic=24023.msg299987#msg299987


That's the infuriating part--The float needles are brand new. I just purchased them from Murph's week before last.

Offline jim-d

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Re: No Combustion
« Reply #27 on: April 08, 2019, 05:33:18 pm »
Ha, I've become a cautionary tale on what not to do to a carburetor.
I feel your pain, believe it!

Left a note for Steve, have not heard back.

Carbs coming back out tonight.

Offline bigdt73

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Re: No Combustion
« Reply #28 on: April 08, 2019, 05:44:15 pm »
Ha, I've become a cautionary tale on what not to do to a carburetor.
I feel your pain, believe it!

Left a note for Steve, have not heard back.

Carbs coming back out tonight.

This will be the fourth time that I'm reinstalling the carbs. I don't like to quit but I'm losing my patience.

Offline jim-d

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Re: No Combustion
« Reply #29 on: April 08, 2019, 06:55:58 pm »
Seriously.
What is the hardest part for You?  Took me 3 hours to get those friggin boots back on.  Now I’m worried I’ll rip them and then something else to buy.  But that was definitely the most frustrating part.

Couldn’t find that bar Steve has in the vid and I’m not ready to tourch a good screw driver just yet.

Makes you doubt your sanity.  I know they worked when I bought the bike.

I’m just trying to get it running to sell it and motorcycle frenzy season is not going to last ‘til August.

No pressure!

We need a therapy group thread.