Re: The OS CZZ is back together, but will it run?
Posted: Sun Jul 21, 2024 8:56 pm
Amazing, thanks for the resource! So looks like I need the orings for the nozzle assembly and then for the carb to crankcase. but some of my observations were correct about the needles themselves not having any orings on them to seal. I guess it just relies on the threads creating a fluid seal. Very interesting stuff. Thanks again.
I may rebuild mine at some point, and the connecting rod has a bit of play but nowhere near what ops had. Thats nuts. Once you add up all the prices for the parts needed to rebuild it is kind of hard to justify.
Mine would probably run ok with just new bearings, connecting rod, wristpin and teflon pucks but still then might as well get a p/s
Oh yeah and ZED32, The surging at idle problem is usually because the low speed is too lean, but heres the thing it usually only happens towards the end of the tank when the mixture is generally leaner and when the engine is at its upper temperature. Higher temperature will make the engine run more efficiently or leaner. Usually the classic tuning problem that gets blamed on air leaks, but like I said this carb only has 2 seals. so really what happens is engine wont run well when cold, leans the low speed, engine gets up to temp, wont idle down so idle gap is closed to way less than 1mm. engine can run at lower rpm but is still lean.
So basically, set the idle gap to 1mm or maybe a little less like .7 and then if the engine wont go back to idle within an instant or within a second of giving it gas, richen the ls an hour and see if that improves. Of course if the engine is at least 230f and cleared out and then immediately bogs and dies after giving throttle can try leaning an hour and see if it improves. Can also be a glow plug issue, or from lack of pinch
I always just try and shoot for the middle, lean enough on the low speed that the engine wont die when warmed up and on a full tank, but rich enough that the engine will stay at a high idle for maybe like a second at the end of a tank but then drop down into a lower idle after sitting. you can experiement and see what works best for you.
I may rebuild mine at some point, and the connecting rod has a bit of play but nowhere near what ops had. Thats nuts. Once you add up all the prices for the parts needed to rebuild it is kind of hard to justify.
Mine would probably run ok with just new bearings, connecting rod, wristpin and teflon pucks but still then might as well get a p/s
Oh yeah and ZED32, The surging at idle problem is usually because the low speed is too lean, but heres the thing it usually only happens towards the end of the tank when the mixture is generally leaner and when the engine is at its upper temperature. Higher temperature will make the engine run more efficiently or leaner. Usually the classic tuning problem that gets blamed on air leaks, but like I said this carb only has 2 seals. so really what happens is engine wont run well when cold, leans the low speed, engine gets up to temp, wont idle down so idle gap is closed to way less than 1mm. engine can run at lower rpm but is still lean.
So basically, set the idle gap to 1mm or maybe a little less like .7 and then if the engine wont go back to idle within an instant or within a second of giving it gas, richen the ls an hour and see if that improves. Of course if the engine is at least 230f and cleared out and then immediately bogs and dies after giving throttle can try leaning an hour and see if it improves. Can also be a glow plug issue, or from lack of pinch
I always just try and shoot for the middle, lean enough on the low speed that the engine wont die when warmed up and on a full tank, but rich enough that the engine will stay at a high idle for maybe like a second at the end of a tank but then drop down into a lower idle after sitting. you can experiement and see what works best for you.