nrcb125
Been Around the Block
Put new rings in my CB125S and was all excited to ride today, but nothing went to plan.
At first, there were fuel problems. I hate these fucking brass floats. Got it fixed.
Then there were electrical problems. Going to solving this with a new wiring harness in the next couple of weeks.
Decided to bypass is for today... Hooked up my car battery (it's been running on a 12V system for over a year now so 12V is not an issue).
I kept it simple. No wiring harness, only the +12V (there's a 2 Ohm 20 Watt resistor to make this work with the original coil) and ground. Battery grounded to the frame, and the +12V hooked to the resistors which are hooked up to the coil. Attached is a wiring diagram showing how I had everything connected.
Cue me kicking the thing over like a jackass for quite some time, flooding the cylinder a couple times, airing it out, flooding it, and repeat (good entertainment for the neighbors!) and the little bastard doesn't want to run.
As best I can tell it's not the fueling and it's not the electrics. I'm thinking it might be the points timing or it might be the compression. The plan is to grab a compression tester on the way home tomorrow and double check the points tomorrow.
From doing some basic calculations (PV = nRT strikes again!) I think the pressure should read around 135 - 140 psi. Below is the math. Does that seem reasonable?
Using:
P1*V1 = P2*V2
9.4:1 compression ratio -> V2 = (1/9.4)*V1
Air pressure at sea level is ~14.7 psi
14.7psi * 1 = P2*(1/9.4) -> P2 = ~138 psi
Any other ideas or thoughts? Maybe something I missed?
At first, there were fuel problems. I hate these fucking brass floats. Got it fixed.
Then there were electrical problems. Going to solving this with a new wiring harness in the next couple of weeks.
Decided to bypass is for today... Hooked up my car battery (it's been running on a 12V system for over a year now so 12V is not an issue).
I kept it simple. No wiring harness, only the +12V (there's a 2 Ohm 20 Watt resistor to make this work with the original coil) and ground. Battery grounded to the frame, and the +12V hooked to the resistors which are hooked up to the coil. Attached is a wiring diagram showing how I had everything connected.
Cue me kicking the thing over like a jackass for quite some time, flooding the cylinder a couple times, airing it out, flooding it, and repeat (good entertainment for the neighbors!) and the little bastard doesn't want to run.
As best I can tell it's not the fueling and it's not the electrics. I'm thinking it might be the points timing or it might be the compression. The plan is to grab a compression tester on the way home tomorrow and double check the points tomorrow.
From doing some basic calculations (PV = nRT strikes again!) I think the pressure should read around 135 - 140 psi. Below is the math. Does that seem reasonable?
Using:
P1*V1 = P2*V2
9.4:1 compression ratio -> V2 = (1/9.4)*V1
Air pressure at sea level is ~14.7 psi
14.7psi * 1 = P2*(1/9.4) -> P2 = ~138 psi
Any other ideas or thoughts? Maybe something I missed?