pilot screw questions..

hey guys. wondering if i should really worry about this. im in the market for a new carb body and ive found one thanks to a member on here. only thing is his body sports the fine thread pilot needle or screw. and i have steel coarse thread. my question is how much of a pain will this be to deal with one non matching needle? obviously the number of turns to achieve the results i need are going to be different but thats it right?

 

Unless I am confused in what your asking... Which is possible.. You would not want to thread, the coarse threaded pilot screw into the fine threaded carb body. Doing so will most likely severly damage if not destroy the carb body threads. If I recall the 1980-81 Hsc32-33 carbs on the xj650 all used the coarse thread pilot screws. The 1982 and up xj650's all used the ultra fine threads. You are correct in that the fine threads ( in both pilot screw and carb Body) will allow for a more precise level of fine tuning. But I would not mix coarse screws with ultra fine threaded carb body, you will strip the threads. New ultrs fine thread screws are available from Chacal. The entire kit to do the bank of carbs is about $75. Part HCP839KIT4

 

Deadly, you are correct in your assumptions, however, the coarse-threaded screws do not (in practice) allow for as fine an adjustment as the fine-threaded screws do (which is probably why Hitachi "improved" their design to the fine threaded screws over time). You might end up with a bit of difficulty getting the entire carb rack synched, although with enough patience, it can be done.

 

Provided the screws are the same lengths overall, the only accurate way to set them would be the "depth measurement" method rather than by counting the same number of turns out as the other three.

 

Okay guys. Thanks for the info. And defo a good idea on the depth mesurement. Assuming they are the same length. I think I may have found a Carb body to match though. The pilot screws only effect mixture at idle correct? How I've always set them on 2 stroke outboards is to screw them in until the cylinder misses then back it out till it hits and do another quarter turn. Sound effective for these bikes?