Author Topic: Firing order number vs. cylinder number ?  (Read 8986 times)

Offline WTexCliff

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Firing order number vs. cylinder number ?
« on: June 04, 2011, 11:12:35 am »
Hello, I am considering doing my own valve adjustment and am looking around to make sure I  understand what is involved. As I exposed the cylinder head cover and looked at the spark plug  wires I noticed they were numbered 1, 2, 3, 4 from left to right.  The Clymer's manual (p56) shows the firing order as 1,2,4,3.  Although it appears cylinder number and firing order are two different  things, I was hoping someone could verify that.

This is how it exists now if cylinder #1 is leftmost and cylinder #4 is rightmost

Left coil left spark plug wire:
Wire #1, Cylinder #1, Firing position #1

Left coil right spark plug wire:
Wire #4, Cylinder #4, Firing position #3

Right coil left spark plug wire:
Wire #2, Cylinder #2, Firing position #2

Right coil Right spark plug wire:
Wire #3, Cylinder #3, Firing position #4

Thanks

Offline T Cro ®

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Re: Firing order number vs. cylinder number ?
« Reply #1 on: June 04, 2011, 11:45:39 am »
This 4 banger and many others have the cylinders are numbered 1-2-3-4 from the bikes left to right while sitting on the bike. The Firing order is 1 and 4 fire together and 2 and 3 fire together this is called wasted spark ignition and is very common. When number 1 is at TDC compression number 4 is at TDC also with the exhaust valve open, same for 2 & 3 when their turn comes around, etc and vice versa......

I don't know or care what the Clymer's book says; it has been known to be wrong on numerous items.

Left Coil fires 1 & 4 black wire (-) firing signal
Right Coil fires 2 & 3 green wire (-) firing signal
Each share a common red (+) 12VDC switched
Tony P. Crochet
(SOLD) 01 Concours Winner of COG Most Modified in 2010
Ask me about a set of Stick Coils & Harness or Precision Shift Linkage for your C10 Concours

Offline Centex

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Re: Firing order number vs. cylinder number ?
« Reply #2 on: June 04, 2011, 11:56:14 am »


Edit - T Cro beat me to it .... he's the coil pro for sure  :hail:


Cylinders are numbered 1-4 from left to right as sitting on the bike looking forward.

Firing order is, as stated in Clymers, 1-2-4-3

The coil with the small black and red wires goes to cylinders 1 & 4

The coil with the small green and red wires goes to cylinders 2 & 3

The red wires are the same - they can be swapped between coils without harm; the black and green wires must end-up routed to the correct cylinders through a coil.

It does not matter which side the coils are mounted on or which of the two sparkplug wire 'towers' on the coil go to which plug for that coil - when the coil fires, both connected plugs fire (one is a "wasted spark").

I'm staying away from your left-right terms just in case a PO changed coil locations but managed to get all the wires to reach the correct destination (or if you manage to lose track of locations during the project).  8)

HTH
Alan in Central Texas
2004 Connie COG 9476
2001 Ducati M750

Offline WTexCliff

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Re: Firing order number vs. cylinder number ?
« Reply #3 on: June 04, 2011, 12:10:09 pm »
Thanks T Cro and Centex,

That makes sense with what I have.  That helps me be certain before I begin taking things apart.

I appreciate your feedback.

Thanks

Cliff

Offline medicevans

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Re: Firing order number vs. cylinder number ?
« Reply #4 on: June 04, 2011, 12:59:35 pm »
Don't be too intimidated about the first valve adjust. It's a lot to take in all at once, but it's not too bad once you get going. When you tighten the valve adjusters, remember to hold the screw with a screwdriver as you tighten the set nut. It keeps things in spec. Just come back and ask questions often if you need help. Also, do one cylinder at a time, both intake and exhaust. Then move to the next cylinder. I can't remember if the cam lobes point towards each other or away from each other. Someone else can help me on this?

Offline Jet86

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Re: Firing order number vs. cylinder number ?
« Reply #5 on: June 06, 2011, 12:03:50 am »
As long as the big lobe part is NOT on the valve holding it down it's ready to adjust if it needs it.

I Adjust all the intakes first then outtakes, this way i don't have to go back and forth with the feeler gauges. just bump the starter til the lobe is off the valve, i try to bump til the lobe is close to straight up.


1986 California Connie 87k and counting

Offline RFH87_Connie

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Re: Firing order number vs. cylinder number ?
« Reply #6 on: June 06, 2011, 06:48:49 am »
As long as the big lobe part is NOT on the valve holding it down it's ready to adjust if it needs it.

I Adjust all the intakes first then outtakes, this way i don't have to go back and forth with the feeler gauges. just bump the starter til the lobe is off the valve, i try to bump til the lobe is close to straight up.

This is pretty close to how I do mine.  I do the first two cylinders on one side (both intake and exhaust) then move around to the other side, and do those.  What Jet is telling you (I think) is that there is no need to take off the pulser cover and make sure the piston is at TDC.  This way you don't need to disturb the cover's gasket.  You don't even need to unscrew the inspection hole.  All you need to do is to use the starter and bump the engine so the lobe on the set you are adjusting is facing away from the lifters.  I usually make the intakes face rearward and the exhausts face forward, both horizontal to the ground (but it's not exact).  The cams are cut round except for the lobe.

To book says to set them at .006" on the intake and .008" on the exhaust.  I have read in the past that a few individuals have set them at .007/.009 with no ill results.  I think it gives a little bit longer on the valve adjustment time with less possibility of one closing up.
“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 WTexCliff

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Re: Firing order number vs. cylinder number ?
« Reply #7 on: June 06, 2011, 11:56:25 am »
Thanks for everyone's advice. 

I will probably wait until next Saturday to go ahead and do the valves so I will have all day if necessary.  Actually, I plan on doing it by the book the first time (I know,...what a newbe) then take the faster route next time. Hopefully, like most servicing I have done on this bike it seems intimidating at first then straightforward after the fact.