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Discussion Starter #1
hi everyone, I am starting to pull my hair out over this bike. Bike runs but it seems it isn't running on all cylinders. So I frist pulled the plugs off while the bike was running to see which ones were good and bad. Cylinder 1 rpms didn't change. Cylinder 2 rpm's went up (suprised me). Cylinders 3 and 4 rpm's went down. Now I am stuck because I know they are all sparking but not sure where to go from here...any help would be greatly appreciated.
 

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Now I am stuck because I know they are all sparking

And just how did you determine that?
 

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Discussion Starter #3
I pulled the plugs while connected still and held them to the cooling fins then kicked the bike and they all sparked up...
 

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remember when your in the carbs to check the float height. i don't know how many times i have talked with people who have told me the carbs are clean and then they have to tear them back out for float height.

just thinking about carb rebuilds makes me remember how nasty gas can be after it sit for a couple of years.

also is the inside of your tank rusty? get a new inline fuel filter.
 

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Discussion Starter #6
Yeah I set the floats at 22mm, and this stopped the fuel from dumping ou the far left carb.

Wires maybe??
 

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Discussion Starter #7
Yeah I set the floats at 22mm, and this stopped the fuel from dumping ou the far left carb.

Wires maybe??
 

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I don't think your check for spark correctly. Try connecting a known good spark plug to the plug wire and let it rest against the motor head (don't hold it yourself unless you need a good wake up shock) so the bottom of the plug is touching the head. (You don't need to uninstall the existing plug to do this test).

Turn on your key and hit the starter button while looking at the plug. You should see a spark jumping on the electrode of the plug. Perform this test for all plugs. If your missing a spark - then check your ignition system (plugs, points and coils or timing). If the plug is wet when it's removed from the engine then your getting gas into that cylinder.

Not running on one or two cylinders is a common issue. If the problem is with cyc # 1+4 or # 2-3 then you have a common problem between the ignition and or coil. The bike is designed to fire both plugs together.

Good luck and let us know what you find...
 

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I don't think your check for spark correctly. Try connecting a known good spark plug to the plug wire and let it rest against the motor head (don't hold it yourself unless you need a good wake up shock) so the bottom of the plug is touching the head. (You don't need to uninstall the existing plug to do this test).

Turn on your key and hit the starter button while looking at the plug. You should see a spark jumping on the electrode of the plug. Perform this test for all plugs. If your missing a spark - then check your ignition system (plugs, points and coils or timing). If the plug is wet when it's removed from the engine then your getting gas into that cylinder.

Not running on one or two cylinders is a common issue. If the problem is with cyc # 1+4 or # 2-3 then you have a common problem between the ignition and or coil. The bike is designed to fire both plugs together.

Good luck and let us know what you find...
 

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Discussion Starter #10
Thanks for all the suggestions...I tried everything everyone mentioned tonight. So here's where I am now, which feels like no where.

Tested all wires fro spark with new plug (spark from all).
Gapped points to 3/4mm...

Ok it appears that I am running decent on cylinders 3+4 so I am lost again...
 

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Discussion Starter #11
Thanks for all the suggestions...I tried everything everyone mentioned tonight. So here's where I am now, which feels like no where.

Tested all wires fro spark with new plug (spark from all).
Gapped points to 3/4mm...

Ok it appears that I am running decent on cylinders 3+4 so I am lost again...
 

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i'm pretty sure that points should be 3/10's of a mm. .012" seems to ring a bell in my head.

I'm going to go with fuel issue on this one.
but be sure to check valve adjustment. the po may have thought loose rocker arms are bad and closed up the gap all the way getting rid of your compression because the vlaves aren't closing all the way.
 

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i'm pretty sure that points should be 3/10's of a mm. .012" seems to ring a bell in my head.

I'm going to go with fuel issue on this one.
but be sure to check valve adjustment. the po may have thought loose rocker arms are bad and closed up the gap all the way getting rid of your compression because the vlaves aren't closing all the way.
 

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Discussion Starter #16
Checked the plug wires (they were also numbered according to cylinder) they were good.

I will double check the points gap again. Is it normal to see some sparking coming from the points? Also when I would get it revving it started back firing and shooting flames out the 1+2 exhaust, why would that be happening.

I have to buy inch feeler guages. Tonight I will check the valve adjustments (Thanks).

I just don't understand why the engine would speed up when I pull off the plug for cylinder 2.

Thanks for all the help...I will post tonight after run through again.
 

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Discussion Starter #17
Checked the plug wires (they were also numbered according to cylinder) they were good.

I will double check the points gap again. Is it normal to see some sparking coming from the points? Also when I would get it revving it started back firing and shooting flames out the 1+2 exhaust, why would that be happening.

I have to buy inch feeler guages. Tonight I will check the valve adjustments (Thanks).

I just don't understand why the engine would speed up when I pull off the plug for cylinder 2.

Thanks for all the help...I will post tonight after run through again.
 

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one thing that you may want to look into is the compression. i know that it wouldn't cause this exact problem, but it may help in deciding the next steps.
 

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one thing that you may want to look into is the compression. i know that it wouldn't cause this exact problem, but it may help in deciding the next steps.
 

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quote:Originally posted by smorris


I just don't understand why the engine would speed up when I pull off the plug for cylinder 2.
because when you removed it fromt he equation, cyl 3 then started firing again. I think 2 and 3 were both not firing and then unplugging 2 made more energy get to 3 and made it able to jump the plug gap. are these all new plugs?
 
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