Yamaha Starbike Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
Hello all: I have been getting a intermittent spark from my 2003 Vstar classic in one cylinder. Its happened twice now the first time I thought I cured it but it seems to be back
What I did
Tested the plug - no spark
Tested at the wire - no spark
Test the coils by hooking the wires from cylinder 1 to coil2 -Spark
I also tested the "points" -cant remember the name they use but the spark generator in the engine- it was ok
so now I was at the CDI, I changed the CDI and things started working again. but now the issue has returned
So I checked the connection on the coils and tightened those up but I am still getting the issue
The symptom is one cylinder drops out, this usually kicks back in after a period, but sooner or later the cylinder stops
The replacement CDI is used but I cant believe 2 of these buggers would go bad this fast so I am searching for other explanations
Any ideas?
 

·
Registered
Joined
·
1,315 Posts
Hello all: I have been getting a intermittent spark from my 2003 Vstar classic in one cylinder. Its happened twice now the first time I thought I cured it but it seems to be back
What I did
Tested the plug - no spark
Tested at the wire - no spark
Test the coils by hooking the wires from cylinder 1 to coil2 -Spark
I also tested the "points" -cant remember the name they use but the spark generator in the engine- it was ok
so now I was at the CDI, I changed the CDI and things started working again. but now the issue has returned
So I checked the connection on the coils and tightened those up but I am still getting the issue
The symptom is one cylinder drops out, this usually kicks back in after a period, but sooner or later the cylinder stops
The replacement CDI is used but I cant believe 2 of these buggers would go bad this fast so I am searching for other explanations
Any ideas?
the 650 or 1100 doesn't use a CDI it uses a TCI ignition the ECM is really basic inside it is a switching transistor and a micro processor for moving the timing at different throttle positions most of the pins are for the safety devices for powering the relays the only thing i'v ever seen go bad was a pick up coil and some of the after market ones have the wires switched at the plug which will fry the pick up in no time, never use an after market pick up they're all junk. that's why the oem ones cost's so much if you really look at the oem one it's obviously built better i'll bet if you cut one open the windings are thicker and better insulated start checking all the safety devices engine shutoff, side stand switch, clutch switch, and neutral switch all those switches feed into the ecm and tell the ecm to power the relays, check the pick up when hot and cold when mine went bad it only showed bad when hot. when you switched the coils did the problem switch to the other cylinder, you can also put a noid light on coil triggers to see if there actually triggering the coils, it going to be hard to diagnose if you don't have the right test equipment, you might want to let the dealer do this to save you a lot of aggravation, they say you can't test an ECM but actually you can with the right equipment and a bit of ingenuity. if an ECM can be rebuilt it can be tested is the way i see it
 

·
Registered
Joined
·
2 Posts
Discussion Starter #3
thank you

hey thanks for the reply, it looks like it was the coil, I had tested it and it seemed ok (within the manual specs), but I think it was off and on, I tested it again when the cylinder wasn't working then the secondary resistance was outside the manual specs.
When I spoke to a tech on the issue he felt it wasn't a big deal so I had concluded the coil was good but I decided I was stuck so I just replaced the coil and it seems to be working.
Its a 1100 by the way
 
1 - 4 of 4 Posts
Top