Thanks for the video. I just purchased a Flight Star II with a Rotax 503 engine and I'm having issues with to much compression. Although I don't think its a compression issue, its a pull start engine and I can barely pull the rope past the compression stroke. I have watched several video's of people pull starting their engines and none of them seem to have a problem with this. Any idea's what it might be? Between compression strokes the engine moves freely. It just seems to be high compression. This plane sat in storage for several years and it appears that there are new gaskets on the engine.
It could be build up of carbon on the piston crown and head or the gaskets are too tin witch would increase the compression ratio. Ignition timing could be too far advanced. Hope this helps.
@@pauls.2526 I took the engine apart and it has been rebuilt. There are still hone marks on the cylinder walls. It does need new O-Rings on the crank. They are gone!!!
Great information. I have a 505A Rotax engine and I am happy with it.
Thank you John. This is great information, as always. I just did this inspection per your video.
Another class show... thank you very much
Thank you for your kind comment and your welcome.
Thanks for the video. I just purchased a Flight Star II with a Rotax 503 engine and I'm having issues with to much compression. Although I don't think its a compression issue, its a pull start engine and I can barely pull the rope past the compression stroke. I have watched several video's of people pull starting their engines and none of them seem to have a problem with this. Any idea's what it might be? Between compression strokes the engine moves freely. It just seems to be high compression. This plane sat in storage for several years and it appears that there are new gaskets on the engine.
It could be build up of carbon on the piston crown and head or the gaskets are too tin witch would increase the compression ratio. Ignition timing could be too far advanced. Hope this helps.
@@pauls.2526 I took the engine apart and it has been rebuilt. There are still hone marks on the cylinder walls. It does need new O-Rings on the crank. They are gone!!!
anyone know the ID Of a 503UL intake manifold?
I think 38mm
40:1 mixx ??
The 503 in this video is mounted inverted on a Challenger II. Mix is 50:1 Petro-Canada 91 with Castrol Go 2T.
40 to 1 is great