Mikuni Spring Color & Popoff Pop Off Chart

[nikko mercado]

is there any explanation or step by step procedure on how to do a pop of test?i just rely on my mechanic on this one and his out of town so maybe some pics and explanation would do.

[birdgod]

from this post http://www.greenhulk.net/showthread.php?t=172956

[macGruber]

is there any explanation or step by step procedure on how to do a pop of test?i just rely on my mechanic on this one and his out of town so maybe some pics and explanation would do.

1. Clean and rebuild carb.
2. Figure out what you need your popoff pressure to be.
3. plug off all fuel inlets and outlets on the carb except for one fuel INLET.
4. connect your popoff tester to the last Inlet
5. Remove metering cover on the carb.
6. Fill the entire metering side of the carb with WD-40 (I fill it all the way up till the top of the metering spring and arm are submerged.
7. Press the metering lever/spring a couple times to allow WD40 to drain down into the carb till it stops taking it.
8. Start pumping pressure into the popoff tester
9. Note what PSI your carb pops or starts fizzing at (the pop will blow WD40 up into your face and into the air so do this somewhere that you don't mind lubricating and USE eye protection!
10. Repeat at least 2 other times to get a good average

If your popoff is higher than you desire...you can cut the windings off of the bottom of the spring till you lower it to your desired result or just select a different spring if you have them available and repeat the test till you find the right one. OsideBill said trimming was perfectly fine on the springs so I tried it and then checked them after a season of riding and the popoff has not changed. I cut 1/2 of a winding at a time till I got down about 5 windings one time to drop from 70psi to 55psi. Didn't have any springs and needed to get the carbs done quick that time.

[steve45]

If you can't tell which spring is which, simply push 2 different springs together. One will be stronger and compress less than the other. Keep doing this until you figure out which is the strongest, second strongest, etc.