fuel to right bank, no spark

[motoman]

I also notice that cyl. 3 & 4 are not firing the new plug, (switched, and the same thing). semmed kinda odd, as 1 & 3 fire off same ciol, and 2 & 4 fire off other coil. Can anyone help as to what the problem is?

[skids]

Re: Ignition problem(spark plugs)

Think this through again, because 1 and 4 ARE fired from the same coil, and, 2 and 3 are fired from the opposite coil.

Originally posted by motoman
I also notice that cyl. 3 & 4 are not firing the new plug, (switched, and the same thing). semmed kinda odd, as 1 & 3 fire off same ciol, and 2 & 4 fire off other coil. Can anyone help as to what the problem is?

[motoman]

Thanks for correcting me on that coil firing order. Anyway, 3 & 4 are not firing. A week ago, all four fired fine when I got the bike back, cept for the carbs needed work, as it did not idle well. I had replaced plug ends, as old ones were cracked and corroded. Even at that it ran decent on all four prior to that. Does it all of a sudden have an ignition module problem, or is the problem something simple that I'm overlooking? Also, by putting in the 78 engine- tranny in my 81 venturer, even tho the coils plug in individually on 78, and have two seperate snap plug-ins on 81, are the ignitions and advances on both the same?

[rover]

nope

[Ken Talbot]

Originally posted by motoman
Anyway, 3 & 4 are not firing. A week ago, all four fired fine when I got the bike back, cept for the carbs needed work

There's your major clue. 3 and 4 are served by the same fuel feed. Look for a kinked fuel line, or a cracked or disconnected petcock vacuum hose.

[skids]

I did that engine swap (actually I did a 80G engine into an 81H). The ignition pick-up assembly for the 81 should be used in the 78E engine. This is because the pick-ups for the 81H and the TCI box are designed to work together.

Originally posted by motoman
Also, by putting in the 78 engine- tranny in my 81 venturer, even tho the coils plug in individually on 78, and have two seperate snap plug-ins on 81, are the ignitions and advances on both the same?

[motoman]

Thanks Skids, I presume that looks like a real simple swap.

[motoman]

fuel to right bank, no spark

I'm getting fuel to two right cyl., but no spark, engine running on left two cyl., right exhaust coming out and plugs both cold on right side. Sorry guys....age and memory slippin here....maybe some of ya's can hit refresh for me.....Thanks

[thumperjsa]

Check for air leaks at the intake and make dure you are getting fuel mixture. Also, are the plugs wet in the cylinders that are not firing.
Unless I am missing something.

[motoman]

Right cyls. that are not firing are getting fuel, and plugs are wet eith fuel.....yeppers

[TopCatGr58]

Hey there Motoman,

I merged your threads! When trouble shooting a problem, it's best to keep replying to the same thread, so that others that try to help can see the history of the problem, the steps that have already been done, the suggestions already mentioned, etc.. IF you keep making new threads, then you run the chance of getting many repeated ideas due to NOT knowing the previous info from the "other" threads!

Okay, basics, you got fuel, you say you swapped the spark plug wires, but before when not knowing/remembering which ones are paired properly, you may have swapped the wrong ones, which would have fired at the wrong time!? So...you might want to try swapping #1 with 4, and #2 with 3 to see if the hot cylinders move? If they do, then you can chase down the electrical....but it won't be specific to just one coil, or the pickup coils, or the TCI since you might have problems with both sets, but only 1 of each set? So...could be bad plug wires, even though you cut back the ends? Could be bad plug caps, their built in resistors can get corroded and prevent current flow?

You said it smoked a bit out of the right side, was it white/grey smoke, or blue/black? Let me see if I remember this, cause I've been corrected before, white/grey=oil, black = rich/fuel.

Also, have you done a compression test on those cylinders? Could be bad rings or burned valves leaking not developing enough comp to fire properly?
Good luck, keep at it! T.C.

[motoman]

Thanks guy, being new, I'll try to follow all that on new threads and staying on old one. As for bike, plug wires are on correct plugs as the order never got changed(wires still have orig. no. on them). 3 and 4 are not firing, (couple days prior, after getting bike back, even tho clutch slipped, I took it for a ride, bout 15 miles, have put 32 miles on tripodometer total. It just seemed kinda curious that it would suddenly not fire those two plugs, as those cyls. are getting fuel. I swapped plugs 1 and 2 with 3 and 4 and the same results, so its not the plugs. Just thought maybe someone would have the quick answer as what to check with out guessing. Even with fourty years of automotive engine building and diagnosis, this thing hittin' good on all four, and next day not left me baffled, as I don't but about half that experience on bikes, and most of that is with 2-stroke since I still race competively.. Any ways.....just thought I'd throw that deliema out there for u all...see what answers I got and go from there..Thanks.

[TopCatGr58]

Hey there Motoman,

No affronts to your knowledge or experience were ever intended. Regrettably, over the net many of us ARE guessing as to what to look for!? The commonalilties of the 2 right cylinders are few. Aside from the fuel supply which you have stated is correct, with wet plugs, the Exhaust also comes to mind. Lots of rust can build up in the pipes, and break loose and clog the outflow. Have you put your hand over the mufflers to see if the same volume is being pumped out?

I had an old Turbo T-bird 4 cylinder, that all of a sudden lost power big time!! Turned out the Catalytic converter innards broke in to several pieces and twisted and turn and almost totally blocked the outflow which really killed the INFLOW and performance. Once a new CC was installed, it ran strong again!

Sorry, no magic bullet so far, good luck, let us know what you find WHEN you get it running on all 4 again!
T.C.

[pggg]

So each coil is sparking only 1 of it's 2 plug leads? What happens if you swap round red/white grey and orange connections?

[randy]

pggg,

Each coil fires two plugs at the same time. The orange for 1&4, the gray for 2&3.

The simple trick is that of each pair of cylinders is timed 180 degrees out of phase with each other, so one plug is firing on an exhaust stroke while the other is firing on a power stroke. Same thing for the other pair of cylinders.

This is known as a 'wasted spark' system.

If you swap the orange and gray it won't run at all. it will however backfire through the carbs every few revolutions.

Don't ask me how i know this!