Help with an RD400d

[canucklehead]

Hi again:
I am having an issue with my freshly rebuilt RD400D, I got rid of the points and put in a system by VintageSmoke in the USA, the bike ran great for 100km then the left side stopped sparking, changed the coil and left side sparked again. The bike just won't run on the left side until it is hot which makes it hard to start. Once running it will tick over at 1500 open the throttle and it will hesitate, then jump to 4000 then drop back to 1500 and then quit altogether. I've checked every lead and connector but I'm out of clues? Could this be electrical or is it carburation, those carbs have been off and on so many times now! I put 27.5 pilots in, then changed back to 22.5s no difference, I run a 145 main, tried going up and down no change. The only thing different is the magnetic ignition system which doesn't have any moving parts and really shouldn't be the problem. Any hints from anyone would be very much appreciated.
Cheers Canucklehead.

Here's a pic:
s19.photobucket.com/albums/b193/GraemeB/?action=view¤t=xstank005.jpg

[Norbo]

Have you swoped the HT leeds over to see if the problem swops over if it does you know its the new sistem but if its the same then its not the spark then its most likely the carbs or reed blocks have you looked at the reed pettels to make sure they are not broke on the problem side .

[canucklehead]

I swapped the HT leads over, no change. I also took the reed blocks out and changed the reeds so they fit nice and tight. Went through the carbs as well, still nothing. I just don't seem to have spark on the left until the motor is hot and then the spark is off and on......
Weird.

[Norbo]

Well if you swoped the Ht lines over and the problem is still on the same side you know its not the spark its something elce .

Id look up the barrels you may have a broken ring on that side .

If its not carbs or spark it must be somthing elce so id look at the pistons .

[canucklehead]

Think I got it sorted, I rechecked the compression and it had dropped to 85 from the rebuild 110, there was a slight leak in the head gasket. I re-annealed the head gasket both sides, re cleaned the carbs and off she went. Still runsa little rough but at least she's going on both cylinders. It's sure handy to get a different perspective on it through this web site.
Thanks for the help Norbo!
Cheers.
Canucklehead

[Norbo]

Glad to hear you have it sorted