Valve clearance points and carb

[Marcus]

What should the valve clearance be on a z50a 1969?..also should the points be adjusted..the spark plug is brand new after riding it for a while the plug has alot of carbon buildup that being said what should be the needle position and I live in Florida what main and pilot should I have for say 80 degree weather..I just did a complete rebuild on the engine

 

[hrc200x]

http://dratv.com/sevacl.html do valves when engine is cold. Points .012"-.016" When T on flywheel is strait up with the index mark and it must be on the compression stroke which is when both valves are closed. Main jet 50, pilot 38.

 

[Marcus]

Ok good deal..how do I know when the valves are closed..and how do I know it's on the compression stroke?

 

[Clayton]

I take both of my tapped covers off and with one hand place a finger on both rocker arms and with my other hand I spin the fly wheel. You can then feel the valves move like they should through the different strokes. After a few turns you can tell when you are on the compression stroke ( both valves closed or down ). Also make sure to pull your spark plug so you can spin the engine easily.

 

[Marcus]

Cool.. I moved the needle to the 3rd position and pulled the plug after a while of riding and the plug had a ton of carbon build up on it..what position should the needle be in? Also do I need to measure the float depth?

 

[hrc200x]

Middle notch with the clip is usually factory setting, you can raise the clip which would lean the mixture. Also the external pilot screw is usually around 1 1/4 turns out from lightly seated. Float level is important but I rarely need to adjust it. From another site it says to do this to set float level. 18mm with the float hanging straight down, tang just touching the valve pin

 

[Marcus]

Cool.. I moved the needle to the 3rd position and pulled the plug after a while of riding and the plug had a ton of carbon build up on it..what position should the needle be in? Also do I need to measure the float depth?

One oth

 

[Marcus]

One oth

Ok...why do you think there's so much carbon buildup on the brand new plug?

 

[Marcus]

One oth

One other thing is I checked the clearance between the rod and crank and it's just within spec should I worry that it's right at the point of needing to be serviced?

 

[PoppaBear]

Marcus, the carbon buildup on your plug means you're running it rich. Here's some tips that work for me before chasing the carb tuning: Make sure your engine rebuild is not burning oil, and the rings/valves have seated properly first (compression test). Use the correct heat range spark plug. Have a good clean air filter and free flow into your carb. Now you can start tuning the carb as stated above (float levels, needle clip positions, jet sizes, etc). I have chased carb jetting, when it was a simple fix to replace the air filter.....

 

[Marcus]

Marcus, the carbon buildup on your plug means you're running it rich. Here's some tips that work for me before chasing the carb tuning: Make sure your engine rebuild is not burning oil, and the rings/valves have seated properly first (compression test). Use the correct heat range spark plug. Have a good clean air filter and free flow into your carb. Now you can start tuning the carb as stated above (float levels, needle clip positions, jet sizes, etc). I have chased carb jetting, when it was a simple fix to replace the air filter.....

What would be the correct heat range plug in Florida? I’m not planning on riding it in the summer

 

[OLD CT]

Same heat range as it is in Canada. The one that is in the bike is fine if it's a c7hsa.