Rebuilt CB200 with VM20s - Running one cylinder? - Images and Video

[odin836]

As can be seen in the video and the photos it seems I'm running only one cylinder...

There is a heap of unburnt muck being thrown from one of my exhaust pipes, the muck smells like fuel.
I have not tuned the bike to run efficiently on the VM20s but I have done the basics like check valve clearance, points gap etc. The plan is to get a bike mechanic to tune it correctly once its almost ready for the road.

Both cylinders get good spark when spark plugs is removed and held close frame.
I'm a bit confused what would be the cause..

Any suggestions?? ???

Youtube video of engine running
http://youtu.be/cCoUO-tf0JU

The top pipe is hot to touch, even after a minute or two running the lower is still cold, subsequently its the one throwing the muck...

This is whats coming from the lower exhaust pipe.. :-\

Pretty much covers anything behind the pipe, tyre, shocks, garage door etc... :-\


Thank you.

 

[Big R]

How did the bike run when you got it? All things being equal, I want to say your compression is low. Or your jets were loose and rattled down into the bowls (not likely, but possible).

 

[odin836]

Can not test compression currently, a friend has my compression tester.
I'll grab it from him in a couple of days, I'm hoping its not compression as I've just rebuilt this, perhaps I did something wrong???

This is what it was like when I got it, not running, stuck piston, a couple of boxes of bits...

 

[wildfirexxl]

I'm having the same problem with my 200! Did you ever figure it out?

 

[Bert Jan]

CB200 has one coil and fires when pistons are TDC and BDC. At any particular point, one piston is firing while the other just did. When you have the bike running its therefor impossible to be a electrical problem. You could put the sparkplug caps on the other way around and check if that changes the problem to the other cilinder.
If so, spark plug or cable dead. If not, your good on the electrics. both caps have to ground (thru the sparkplug ) for the bike to fire.
I fought with one a while back - problem was the condenser (between coil and points) had to be grounded. I just hung it in between the wires for bench testing. Once grounded she ran like a champ.

Most likely its a fuel starvation problem as it's not firing at all on one cilinder and as i above told you it's very unlikely that it a electrical problem. Change the carbs from left to right and check if the problem persists in the same cilinder or has changed. If its the same, you have compression problems wich could be valve adjustment, worn rings, bend valves.... If problem changed cilinder it's the carb.