Safe_Cracker
Key Veteran
Location: Chicago, IL
| I found a problem with one of my OS46's today and I need to find out if it is unique to just my engine.I put my heli on a stand today and ran it up.I noticed that the top was sooo very rich and I went ahead and started to lean it out.I would return to idle to check it and the bottom end needed riching so I did.I would then go to full throttle and the top still very rich, hmmm it's only out 3/4 turn, weird...Finally it got to where I needed to turn the needle in to 1/2, 1/4 and next all the way!Yes it was in all the way and still ran rich, very rich.....I took it home and removed the carb.I put a spare piece of hose on the nozzle, opened the throttle all the way and screwed the needle all the way in then I blew into the hose to find out it was seeping past the needle and seat.I removed the needle and mount to inspect the seat/spraybar there was no foreign material present so I tried it again with the same results, the valve wasn't seating.I have both a new version of that carb and an old(40c) one.I compared the two to find out that the old one has a larger hole in the valve seat then the new one.The dimensions on the two are identicle including the needle valves, seats, threading and needle width.You know what that means?The hole is too large on the old one for it to close enough for any usefullness.Try doing what I did.Close your high needle all the way, take a piece of hose while making sure the throttle is open all the way and blow into the hoes to see if you hear the air coming out.Let me know...You should have no air escaping the valve when fully closed.I did find a fix and will see if it works soon.Hopefully this is unique to just this engine and if not I hope this fix I have works.. |
