O.S. 40LA High Throttle inconsistant
08-01-2003 | 08:29 PM
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From: Roseville,
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O.S. 40LA High Throttle inconsistant
I hav an unusual problem with a O.S. LA40 when adjusting the High throttle. When closing the throttle the engine looses RPM's and keeps slowing down. When I go to close the needle valve the engine gains RPM's and keeps on gianing untill it gets too lean. I just stopped playing with it and flew the plane and it flew okey but there was a yellowish gas deposite all over the head. Is this engine ready to toss or is it okey.
08-01-2003 | 09:36 PM
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From: Matsapha, SWAZILAND
OS 40LA
Hi Basil
Sounds familiar so I am going to try and assist. Is this the 40LA with the remote high speed mixture adjustment (needle)? If so I had the same problem.....mine is a OS 46 LA has the same config......was about to toss the thing also but it was brand new so I persisted and almost two tanks later and much looking and probing....turns out that the nipple from the remote to the carb inlet nipple sucks air between the fuel pipe and the remote pipe, on the join where the two meet......reason I worked out was that the nipple on the remote does not have a flanged end, it is just a pipe for want of a word. see the attached pic...well I hope it comes out on the reply...
Remedy was a micro tie wrap…..problem solved and the motor performs perfect and idles perfect…..The yellowish substance is nothing to be alarmed about…all it is s exhaust leaking at the muffler engine join had that two until I used permatex ultra copper high temp RTV silicon gasket maker made by Locktite for the muffler….subsequently all my engines have had mod on the muffler with out a drop….no need for those flimsy gaskets.
Hope this helps
SwaziNev
Sounds familiar so I am going to try and assist. Is this the 40LA with the remote high speed mixture adjustment (needle)? If so I had the same problem.....mine is a OS 46 LA has the same config......was about to toss the thing also but it was brand new so I persisted and almost two tanks later and much looking and probing....turns out that the nipple from the remote to the carb inlet nipple sucks air between the fuel pipe and the remote pipe, on the join where the two meet......reason I worked out was that the nipple on the remote does not have a flanged end, it is just a pipe for want of a word. see the attached pic...well I hope it comes out on the reply...
Remedy was a micro tie wrap…..problem solved and the motor performs perfect and idles perfect…..The yellowish substance is nothing to be alarmed about…all it is s exhaust leaking at the muffler engine join had that two until I used permatex ultra copper high temp RTV silicon gasket maker made by Locktite for the muffler….subsequently all my engines have had mod on the muffler with out a drop….no need for those flimsy gaskets.
Hope this helps
SwaziNev
08-01-2003 | 10:27 PM
#3
O.S. 40LA High Throttle inconsistant
I don't like messing with that gasket goo stuff, so I always cut paper gaskets... they're re-usable, so if you have to take the exhaust of for one reason or another you don't always have to reseal the damn thing...comes in handy when you're tuning a pipe or something like that...
08-03-2003 | 07:09 AM
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From: Roseville,
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O.S. 40LA High Throttle inconsistant
I thought that tube was not designed right having no shank to seal like most other fittings do. I'll add that tie down. On close inpection I also found that the needle valve stop clip was very lightly stopping the needle valve. The needle could have been turning but I think the tube is probably it. The plane it was on crashed and I layed it to rest in the garbage can so the engine is up on the shelf. Now I have rolled out the WM Super Sports 40S with a Super Tigre .51 Ringed. Excellent engine it has so much power on that plane it makes the .40 LA Look like a .10. I was told Super Tigre wasn't very good but after using one Wow! It will practically do vertical manuvers with that engine.
08-03-2003 | 07:09 AM
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From: Roseville,
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O.S. 40LA High Throttle inconsistant
I thought that tube was not designed right having no shank to seal like most other fittings do. I'll add that tie down. On close inpection I also found that the needle valve stop clip was very lightly stopping the needle valve. The needle could have been turning but I think the tube is probably it. The plane it was on crashed and I layed it to rest in the garbage can so the engine is up on the shelf. Now I have rolled out the WM Super Sports 40S with a Super Tigre .51 Ringed. Excellent engine it has so much power on that plane it makes the .40 LA Look like a .10. I was told Super Tigre wasn't very good but after using one Wow! It will practically do vertical manuvers with that engine.
08-03-2003 | 07:35 AM
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From: Matsapha, SWAZILAND
OS 40 LA
Hi Basil
Will you be using the engine in the near future..??? If so let me know if that worked. I have to agree ST is a good make but I guess everybody has his personnel choice. I have a ST90 that I am fitting to WM Super Chipmunk at the moment....just waiting for the Pitts muffler I ordered. The ST90 is one that was made in Italy, I believe that they are now made in China and the quality is not too good…that’s what I have read but would like to check it for myself. Sorry to hear about your crash, what happened? Did the OS 40 LA let you down at a crucial moment…..???
SwaziNev
SwaziNev
Will you be using the engine in the near future..??? If so let me know if that worked. I have to agree ST is a good make but I guess everybody has his personnel choice. I have a ST90 that I am fitting to WM Super Chipmunk at the moment....just waiting for the Pitts muffler I ordered. The ST90 is one that was made in Italy, I believe that they are now made in China and the quality is not too good…that’s what I have read but would like to check it for myself. Sorry to hear about your crash, what happened? Did the OS 40 LA let you down at a crucial moment…..???
SwaziNev
SwaziNev
