Float height for Chinese carb

jomi

New Member
Hi, I have CT70 with 110 ccm clone engine and Jing KI PZ19 carb, carb is leaking. And I know that I have to chance the float level. But what is measure in mm? I know what to do because I have setled several time my Honda CBX1000 carbs and also Dellorto carbs in karting engines. I only need to know the correct float level???
 

69ST

Well-Known Member
Welcome aboard:wave:

Hopefully fellow member OLD CT will chime-in on this one. IMO, he's the resident expert on PZ19 carbs.

I can give you some general guidelines, based on decades of carb tuning experience; unfortunately, that's not the same as a factory specification. As long as fuel flow is normal, these things have to be off, considerably, before running problems will manifest. Why do you believe that the float level needs adjustment?
 

jomi

New Member
Welcome aboard:wave:

Hopefully fellow member OLD CT will chime-in on this one. IMO, he's the resident expert on PZ19 carbs.

I can give you some general guidelines, based on decades of carb tuning experience; unfortunately, that's not the same as a factory specification. As long as fuel flow is normal, these things have to be off, considerably, before running problems will manifest. Why do you believe that the float level needs adjustment?

I know that float level must be too high because gasoline is coming all the time when bike is running - and that´s not drop it is like heavy rain. So I have all these measure tools which is needed. But need to know what is correct setting, the needle is ok in valve.
 

69ST

Well-Known Member
Maybe consult the vendor who supplied the carb? This is one of the common drawbacks of Chinese running gear, i.e. lack of tech support.

I get the impression that you know your way around a carburetor so, next best method is determining the float height spec the old-school way...lower it 2-3mm and see if the overflow stops. If not, repeat the process. Unless the float contacts the carb body, you shouldn't have to tweak the level setting very much.

One caveat...you could have a leaky float. It's not super common but, it does happen. Remove the float unit and shake it, listening for the sound of liquid sloshing around inside. If you want to be extra thorough, place the float in the freezer to get it good and cold, then hold it submerged in hot (130-140F) water, looking for small air bubbles as the air trapped inside the floats expands.
 
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