Hi,
I have owned this engine for a few years now and due to other projects it has been left alone under a tarpaulin to keep the weather off it. This is a 'high speed, tropical' model which runs a dry dry sump set up and is why there is the extra filter and oil tank on the back of the engine. Before leaving it alone under cover this engine always started and ran very well. Now I have an issue with it seizing up after running for a very short time. This is out of character and I need to fix the problem. There is plenty of oil in the tank and I do turn the oil tap on before starting and there is oil pressure showing on the original gauge but it is knocked around so I connected another gauge and it shows good pressure of around the 15psi as specified.
When I start it up it takes maybe 3 full swings on the crank handle then use the compression lever and pull it down or push it up , it doesn't matter and it starts. I run it at just above an idle speed and possibly after a minute or so it starts to slow down so I decompress it and shut the fuel off as well.
After this happens I cannot swing the engine over with the crank handle but I can use a pair of stillsons to wind it backwards. Once I have done this I can swing it over on the crank as if nothing has happened.
Any clues as to what to look for please as I miss hearing this run and it is a soothing sound with no muffler just ticking over, even at half revs. Any help is greatly appreciated so than ks in advance.