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Discussion Starter #1 (Edited)
I brought a V-Star 650 last year, run great the first week or so then became hard to start, would run great after fooling around with choke and throttle to get it running,
Then it started to run on the front cylinder only, kick in on the rear once in a while, plus backfiring,
The trouble shooting started with changing the plugs, then the pickup test failed, was reading like 500 OHMS, changed the pickup, no better, next the coil and spark plug leads test Ok, did the negative ground test and got fire on rear cylinder, So from what I read here the CDI is defective, priced one at the Yamaha dealer at $680.00 plus tax, started looking on e-bay, found a used one for $150.00, order and put it on figuring my problems are over, no dice, runs a bit better with the e-bay CDI seems to run on rear without backfire and exhaust get hot, still no power or throttle response. no power. I have read most of the post here about this rear cylinder weak to no fire issue but no one post what has been done to fix it.
I have ordered a new Dyna 3000 CDI and a used set of coils hopefully it is the CDI because all the test point to this, any and all comments are welcome, sorry for the long post but I am pulling what little hair I have left out trying to fix this problem.

GSLMECH
 

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Discussion Starter #2
No spark on rear

I see there are a few post on the no fire on rear cylinder but no one post what the problem was, I have done all the coil test and have found nothing, could someone please reply that has found a fix for this problem

gslmech
 

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Discussion Starter #4
no sparkrear cylinder

Yes I had to play with the choke and throttle after I replaced the pickup coil it will start and run on the front cylinder without a problem, the rear cylinder has spark about half the time, I did clean the carbs I also syn the carbs. Not sure what to do next.

gslmech
 

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Discussion Starter #6 (Edited)
I believe after I changed everything that the original problem was a weak pickup coil, I ordered and installed a new pickup coil from M-stator in Quebec. rarer then thread the new wires from the pickup coil I cut them inside the cover, I sealed them with RTV and shrink wrap, tested and got the 180 OHMs at the connection under the seat which I did not have before, still weak to no fire on rear cylinder. Switched coils from front to back, no differences. Took it to my son and he did some testing and found that the coils + wire had been switched on both coils, this was done before I brought the bike, now I have weak fire on rear cylinder, this not running with any power, next he tested the two wires from the pickup coil under the seat, found out when I cut them, wire colour was different from old coil to new, when I soldered the together I got the mix up, we changed the connectors over under the seat and got full spark front and back cylinder.
So I guess the guy that had the bike before me changed the coil wire around, so the + coming from the ignition was on the wrong side of the coil causing weak fire, plus the weak pickup coil. This was a tough one to figure out, from the mistakes he made and the mistakes I made, I hope this helps you out. Do you have the picture showing which wire is what at the coils, if this is not right you will have very weak fire.
 
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