Help with First Restart After Carb Rebuild

Wookie58 wrote:

SnyperX wrote:

Wookie58 wrote:

 

Yup, that's exactly what i did. Used the ground terminal on the battery as well. I would also note that the voltage of the battery also dropped when I switched the key to start. With the key off the battery returned back to its nominal voltage.

When you say "switched the key to start" do you mean "turned the ignition" on or "cranked the motor" - if cranking the motor the battery voltage will drop to around 10V then bounce back when you stop cranking (this is due to the heavy load drawn by the stater)

Wookie58 wrote:

What did the voltage drop to when you switched on the ignition and what position was the kill switch in ? I wouldn't expect a significant drop under these conditions unless the battery was weak (although it appears to retain enough energy to operate the starter !)

SnyperX wrote:

Wookie58 wrote:

What did the voltage drop to when you switched on the ignition and what position was the kill switch in ? I wouldn't expect a significant drop under these conditions unless the battery was weak (although it appears to retain enough energy to operate the starter !)

The kill switch was in the "Run' position. Voltage drop was maybe a volt from the battery to the coils. From like 12.2v to 11.2v. 

Wookie58 wrote:

SnyperX wrote:

Wookie58 wrote:

What did the voltage drop to when you switched on the ignition and what position was the kill switch in ? I wouldn't expect a significant drop under these conditions unless the battery was weak (although it appears to retain enough energy to operate the starter !)

The kill switch was in the "Run' position. Voltage drop was maybe a volt from the battery to the coils. From like 12.2v to 11.2v. 

Did you take a reading across the battery when you turned the ignition on ?
Try connecting your voltmeter red lead to battery positive and black lead to coil supply then turn on ignition with kill switch in the run position (this will measure the difference between the battery and the coil feed) any more than 0.5v indicated an issue that will increase the longer the circuit is active - if your reading is more than 0.5v and everything else works ok I would suggest you fit a "by-pass" relay ref the link I posted (this is much easier and quicker than working back through multiple connections to check volt drops etc)

Wookie58 wrote:

It is a little high (I believe the spec for your bike is 3-4ohms) the higher resistance will give a weaker spark (especially when coupled with a "volt drop")

Nessism wrote:

Coil resistance spec is something like 2.2 ohms.

Let's reset here.  First start had the engine reving out to a high rpm, right?  That can't happen if the plugs are not firing.  Boots replaced, airbox installed, then problems start.  Sounds like something carb related, not spark.  

Do the choke flaps move smoothly with the lever?  They often bind up, and hang open, thus choke doesn't work, which causes hard starting.  Some starter fluid, carefully used, will test that possibility.

Nessism wrote:

Let's reset here.  First start had the engine reving out to a high rpm, right?  That can't happen if the plugs are not firing.  Boots replaced, airbox installed, then problems start.  Sounds like something carb related, not spark.  


 

SnyperX wrote:

Nessism wrote:

Coil resistance spec is something like 2.2 ohms.

Let's reset here.  First start had the engine reving out to a high rpm, right?  That can't happen if the plugs are not firing.  Boots replaced, airbox installed, then problems start.  Sounds like something carb related, not spark.  

Do the choke flaps move smoothly with the lever?  They often bind up, and hang open, thus choke doesn't work, which causes hard starting.  Some starter fluid, carefully used, will test that possibility.

Ness, yes choke flaps move smooth. I also lubed the choke shaft. In addition I made sure the spring was tensioned enough to make sure the flaps would open fully when disengaged.

Nessism wrote:

SnyperX wrote:

Nessism wrote:

Coil resistance spec is something like 2.2 ohms.

Let's reset here.  First start had the engine reving out to a high rpm, right?  That can't happen if the plugs are not firing.  Boots replaced, airbox installed, then problems start.  Sounds like something carb related, not spark.  

Do the choke flaps move smoothly with the lever?  They often bind up, and hang open, thus choke doesn't work, which causes hard starting.  Some starter fluid, carefully used, will test that possibility.

Ness, yes choke flaps move smooth. I also lubed the choke shaft. In addition I made sure the spring was tensioned enough to make sure the flaps would open fully when disengaged.

Take this for what it's worth, but I've found that lubing the shaft increases drag, and cause the flaps to hang up.  Hopefully, your set is different, though.