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79 KZ650 - Cylinder 1 not running - help!
- Beard
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01 Jul 2010 18:27 - 02 Jul 2010 05:53 #379544
by Beard
79 KZ650B
Jack of everything, Master of nothing.
79 KZ650 - Cylinder 1 not running - help! was created by Beard
I'll try to give you as much info as I can.
I got the bone stock 79kz650, it had a hole in the tank so with a funnel the bike ran. Was cylinder running then? I dont know.
So I start tearing into the bike.
cleaned carbs "sync'd" them with the drill bit method / compression was all 170+ / put on pods / using 17.5 and 110 / new plugs (checked spark at each plug by pulling and having it on block/ proper gap) dyna s ignition / stock coils / timed
Fire up the bike, warmed up, choke off...Things sound fine.. (now i really dont know what it should sound like.. but sounds normal to me)
Pull plugs to look at them. Cylinder 1 looked brand new. I feel cylinder 1 header.. barely warm.. others were hot.
tried a differnt sparkplug in cyl 1, same thing
Pulled carbs recleaned 1. spraying into airscrew while block other ports and it comes out of the carb body hole near the slide. check float level on 1 and 4 with that clear tube thing. They are the same.
Fire up the bike today. same thing cylinder 1 not fire.. plug is wet. piston top is wet. have spark, have compression have air, have fuel..
ohm metered coils, wires, plug boots all matched each other.
preassure at exhaust pipes feels very similar with my hand..
while bike is running.. cylinder 1 pod removed.. cover inlet of carb.. it will suck my hand and spit up fuel.
i have not taken the bike onto the road yet.. this is all driveway, center stand running off a funnel. (have to clean new used tank)
-is my timing off just slightly?
-a coil putting out a weak spark? although in the daytime i can clearly see spark.
-are the coils basically the same? or is there fine difference between them? can i switch the coils from one side to the other.. to see if the dead cylinder follows the coil?
-im not 100% sure how this choke works. as its not a open close flapper... i think i saw the choke enriches some how.. do you think something is stuck there for cylinder 1 and its basically flooding that cylinder? how and where would u check for a choke issue on a single cylinder.
i hope someone has some suggestions.
thanks
I got the bone stock 79kz650, it had a hole in the tank so with a funnel the bike ran. Was cylinder running then? I dont know.
So I start tearing into the bike.
cleaned carbs "sync'd" them with the drill bit method / compression was all 170+ / put on pods / using 17.5 and 110 / new plugs (checked spark at each plug by pulling and having it on block/ proper gap) dyna s ignition / stock coils / timed
Fire up the bike, warmed up, choke off...Things sound fine.. (now i really dont know what it should sound like.. but sounds normal to me)
Pull plugs to look at them. Cylinder 1 looked brand new. I feel cylinder 1 header.. barely warm.. others were hot.
tried a differnt sparkplug in cyl 1, same thing
Pulled carbs recleaned 1. spraying into airscrew while block other ports and it comes out of the carb body hole near the slide. check float level on 1 and 4 with that clear tube thing. They are the same.
Fire up the bike today. same thing cylinder 1 not fire.. plug is wet. piston top is wet. have spark, have compression have air, have fuel..
ohm metered coils, wires, plug boots all matched each other.
preassure at exhaust pipes feels very similar with my hand..
while bike is running.. cylinder 1 pod removed.. cover inlet of carb.. it will suck my hand and spit up fuel.
i have not taken the bike onto the road yet.. this is all driveway, center stand running off a funnel. (have to clean new used tank)
-is my timing off just slightly?
-a coil putting out a weak spark? although in the daytime i can clearly see spark.
-are the coils basically the same? or is there fine difference between them? can i switch the coils from one side to the other.. to see if the dead cylinder follows the coil?
-im not 100% sure how this choke works. as its not a open close flapper... i think i saw the choke enriches some how.. do you think something is stuck there for cylinder 1 and its basically flooding that cylinder? how and where would u check for a choke issue on a single cylinder.
i hope someone has some suggestions.
thanks
79 KZ650B
Jack of everything, Master of nothing.
Last edit: 02 Jul 2010 05:53 by Beard.
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- hardr0ck68
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02 Jul 2010 06:12 #379622
by hardr0ck68
1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
Replied by hardr0ck68 on topic 79 KZ650 - Cylinder 1 not running - help!
Have you checked and set your float height?
I would swap the coils (or even just 1 and 4 plug wires) and see if the problem changes cylinders. If the problem stays in cylinder 1 I would start looking at your carbs again.
When you say you checked the timing, ignition or cam timing?
Also try giving it some throttle, see if #1 starts to fire then (it could be a problem in your pilot circuit)
I would swap the coils (or even just 1 and 4 plug wires) and see if the problem changes cylinders. If the problem stays in cylinder 1 I would start looking at your carbs again.
When you say you checked the timing, ignition or cam timing?
Also try giving it some throttle, see if #1 starts to fire then (it could be a problem in your pilot circuit)
1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
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- cobura
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- forever 2 wheels
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02 Jul 2010 10:55 #379669
by cobura
1979 KZ650B3
Replied by cobura on topic 79 KZ650 - Cylinder 1 not running - help!
I'd like to think that this is one are that i am familiar with. The EXACT same thing happened to me with my 650. Your situation may be different, but for me, it was the carb. Even though i cleaned it a 4 times, it still wasnt any good. Each time after i took the carbs off and cleaned them, the bike would run fine for that day, until the next morning #1 cylinder wouldnt fire on start-up. Checked the plug after trying to start and was very wet. Turned out to be a bad float valve. It was a very very slow leak that would eventually overflow (somehow into the cylinder). I really hate the stock carbs that come on the 650's. I fixed the problem by polishing the inside parts of the float valves with very fine sandpaper. I did the clear tube test and watched it for over three hours. I replaced all of my float pins with new ones, since the previous owner had used pliers to remove them and scratched them up real bad. Last, I also ended up setting my float level lower than spec. Seemed to finally fix it. Also another tip: nasty sludge tends to build up in holes for the choke. Unscrew the choke pulls from each carb section and clean inside there. Also check the rubbers on the choke pulls for cracks or wear.
1979 KZ650B3
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- wannaby
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02 Jul 2010 11:00 #379672
by wannaby
Replied by wannaby on topic 79 KZ650 - Cylinder 1 not running - help!
Hi if the choke rubbers are ripped and torn will that cause it not to run.
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- cobura
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02 Jul 2010 11:03 - 02 Jul 2010 11:06 #379674
by cobura
1979 KZ650B3
Replied by cobura on topic 79 KZ650 - Cylinder 1 not running - help!
not sure, but these old mikuni carbs are really picky. Just take your time and eliminate as many problems as possible. Not kidding, since i bought my bike, I have pulled my carbs at least 10 times.
My choke rubbers were really old and worn. They were flat with the metal and were not making a very good seal. Instead of buying new ones, you can just flip them!
My choke rubbers were really old and worn. They were flat with the metal and were not making a very good seal. Instead of buying new ones, you can just flip them!
1979 KZ650B3
Last edit: 02 Jul 2010 11:06 by cobura.
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- Beard
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02 Jul 2010 12:08 - 02 Jul 2010 12:13 #379682
by Beard
79 KZ650B
Jack of everything, Master of nothing.
Replied by Beard on topic 79 KZ650 - Cylinder 1 not running - help!
can you give me some numbers for the things u mentioned:
namely
choke pulls
holes for choke
float valve
sorry.. im capable but not familiar with carbs and their naming.
i still dont understand how this choke works.
any education would be appreciated
thank you
adam
PICTURE A
PICTURE B
namely
choke pulls
holes for choke
float valve
sorry.. im capable but not familiar with carbs and their naming.
i still dont understand how this choke works.
any education would be appreciated
thank you
adam
PICTURE A
PICTURE B
79 KZ650B
Jack of everything, Master of nothing.
Last edit: 02 Jul 2010 12:13 by Beard.
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- Beard
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02 Jul 2010 22:55 #379832
by Beard
79 KZ650B
Jack of everything, Master of nothing.
Replied by Beard on topic 79 KZ650 - Cylinder 1 not running - help!
to the top, the tippy
79 KZ650B
Jack of everything, Master of nothing.
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- HerrDeacon
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03 Jul 2010 03:48 - 03 Jul 2010 03:56 #379836
by HerrDeacon
Replied by HerrDeacon on topic 79 KZ650 - Cylinder 1 not running - help!
Beard, these VM's don't really have chokes in the traditional sense, they have what referred to as an 'enrichener circuit'. When you lift up on the 'choke' lever you're actually moving the four plungers (parts # 18 - 24 in your second picture). This will add a bit more fuel to the equation to help out the idle circuit on a cold startup. You can see this plunger assembly clearly on the #4 carb, harder to get a look at it on the other carbs. This enrichener circuit gets its fuel from the float bowl via a long brass tube that sits in a section of the bowl. So, make sure this tube, and the section of the float bowl it gets its fuel from, are clear or you'll have problems. I had a blockage in one of mine before and that cylinder wouldn't do much on choke.
If the issue you're having is with the enrichener circuit, the header for that cylinder should be cool during warmup but then heat up when off the choke. Is this how your's is, or is it always cool.
The float valve is part #34 in your picture. If the valve needle (lower of the 34 parts) doesn't seat well (i.e. dirt, worn, etc.) you'll have issues with the carb maintaining the correct fuel amount and then that cylinder won't run correctly (i.e. rich or lean depending on the level).
If the issue you're having is with the enrichener circuit, the header for that cylinder should be cool during warmup but then heat up when off the choke. Is this how your's is, or is it always cool.
The float valve is part #34 in your picture. If the valve needle (lower of the 34 parts) doesn't seat well (i.e. dirt, worn, etc.) you'll have issues with the carb maintaining the correct fuel amount and then that cylinder won't run correctly (i.e. rich or lean depending on the level).
Last edit: 03 Jul 2010 03:56 by HerrDeacon.
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- Beard
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03 Jul 2010 10:06 - 03 Jul 2010 10:12 #379935
by Beard
79 KZ650B
Jack of everything, Master of nothing.
Replied by Beard on topic 79 KZ650 - Cylinder 1 not running - help!
battery was 12.5v was getting 10.2 at the coils.
did that coil mod. voltage at coils is just off a very little bit compared to battery.
cleaned the gas tank this morn.
going to play with the choke thing now.
ive seen posts about people having this issue and when they took it for a ride the cyclinder came to life..
do u think i should take it for a spin around the block?
did that coil mod. voltage at coils is just off a very little bit compared to battery.
cleaned the gas tank this morn.
going to play with the choke thing now.
ive seen posts about people having this issue and when they took it for a ride the cyclinder came to life..
do u think i should take it for a spin around the block?
79 KZ650B
Jack of everything, Master of nothing.
Last edit: 03 Jul 2010 10:12 by Beard.
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- Beard
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19 Jul 2010 19:35 #383970
by Beard
79 KZ650B
Jack of everything, Master of nothing.
Replied by Beard on topic 79 KZ650 - Cylinder 1 not running - help!
tore the carbs apart again.. massive ammounts of compressed air..
all cylinders work now.
thanks all
all cylinders work now.
thanks all
79 KZ650B
Jack of everything, Master of nothing.
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