Intermittent on One cylinder....

[AAAltered]

Since buttoning up the rebuilt bike, I've got a problem with the left cylinder, it's only firing some of the time. 

When the motor came out of the old bike it was running fine.

When I timed it in the new frame, I had plenty of spark, I never noticed it miss.  Now when running it looks like the left cyl only fires some of the time.  You can hear it in the video, and see it in the exhaust.  If I put my hand behind the left can i get covered in unburnt fuel.  Towards the end of the video you can hear it surging as the left fires properly.

Going out there today to try to solve it via the normal process of elimination....

[AAAltered]

FYI it's an R5, VS iggy.....

[AAAltered]

Plugs affirm fuel but no fire....

[Jspooner]

it almost sounds like your carbs aren't synchronized.

[AAAltered]

Great notion Joe, since I am running a brand new throttle cable. 

Need to bone up on syncing them.  Timing is re-checked and it's 1.9BDC (static) so I should be good there.



Thanks
Ed

[AAAltered]

The carb slides were definitely out of sync.  The right slide lifted much sooner than the left.  That's fixed.

The bike seems to idle on its own.  I tried riding it but it still feels like it's running on "1", super bogged down without lots of revs.   The left cylinder feels way less hot to the touch than the left after idling five minutes and a 100 yard attempted ride. 

Someone recognize this behavior?  It sits idling with occasional pops like the left suddenly sparks.  I'm going to start swapping L/R parts such as coil, wires, etc...

[AAAltered]

Plug says no fire in the left hole.  Hahaha I had enough power to go down the block and back (twice) on one cylinder.

[m in sc]

CHECK COIL WIRING.

[AAAltered]

Yea Mark, I think that's the area.  As I mess in there the symptoms change or go away....  too bad I'm out of time for today.  I've had the tank on and off 10 times easy.  Coils are swapped etc.  at some point it runs like a raped ape and some points it dies out.  So the consistent "right side only running" has changed as I worked under there.

On my next garage day I've got to re-re-re-sort the coil wiring......

[m in sc]

you should really use  a good quality ring terminal on the coil wires .. not the hard plastic home depot ones. . and tape them  so they cant arc to the tank (the - side can) .02

[AAAltered]

So I've never seen arcing on my old bike BUT this is a different frame so maybe I am indeed arcing. A mm one way or another could make the difference I assume.  That could explain why it fires up great without the tank, then I plumb the tank in for a test and I hit snags.  I really need an aux fuel feed for this bs.

Thanks all for today.

[m in sc]

yup.

id consider stock coil replacements, they have come a long way. 

[Striker1423]

So I've never seen arcing on my old bike BUT this is a different frame so maybe I am indeed arcing. A mm one way or another could make the difference I assume.  That could explain why it fires up great without the tank, then I plumb the tank in for a test and I hit snags. I really need an aux fuel feed for this bs.

Thanks all for today.

Easy squeezy.

Pop bottle, cork, chunk of fuel line, T-fitting, coat hanger and/or string. Hangs from handlebar and takes about 5 minutes to make.
Don't need a lot of fuel, so cork will hold fine.

Can use cap too, but you'd need to use something to make the line press fit as it will leak. Hot glue does not work, don't try it unless you like globs of Napalm going into your carbs. Ask me how I know.

[AAAltered]

yup.

id consider stock coil replacements, they have come a long way. 

I am sure I have a bunch of Stock coils from my bad Dyna Pickup problem troubleshooting last year....Even new one's somewhere...will hunt them down..

[smokah]

I had that same issue on the same side with the VS ignition on my RD. Ended up being a bad pickup. I ended up going with the powerdynamo.