Hi! I'm new to this forum, so I apologize in advance if I do something wrong with this post. I have a frustrating problem with my Scag and am sure hoping you can help:
It is an ~8-yr old Scag Turf Tiger with the 27hp Koehler engine, with ~300 hrs. I use it to cut my 5 acre lot.
I've always maintained it carefully and it's been a great mower. Now however, it's developed a very frustrating intermittent problem as follows:
The mower/engine runs perfectly for about the first hour. Then, right out of the blue, it starts sputtering and quickly dies if I don't quickly kill the blades and put the throttle to idle.
If I let it idle for a minute or so, then I can resume cutting for 15 minutes or so with no problems. Then...it starts the bobbling again. If I let it cool completely (i.e. overnight), it will run great for the hour or so and then start the issues again.
I thought I had found the problem: a clogged oil cooler. Embarrassingly, I hadn't noticed that it had developed a small leak at the cooler inlet and oil had dripped onto the fins, allowing it to collect a lot of dust, and the fins were completely clogged. I felt sure this was the problem, causing it to get too hot and shut down (heat or oil pressure sensor I hope?). I removed the cooler, cleaned it and the flywheel housing and fixed the leak, thinking that this would solve the problem. It definitely seems to have helped as it runs considerably longer (about 1.5hrs) before the problems starts again. One other item: I can't tell for sure, but the power also seems to be down a bit overall. It seems that the engine chokes down a little when I do a lot of hard turning and I don't remember that occurring before.
As FYI, I have also replaced the air filter, spark plugs, and fuel filter to no avail. The fuel pump is mechanical, so I wouldn't think it is heat sensitive and this sure seems to be a heat issue of some sort.
So....hopefully you can follow my confusing description and I'd sure appreciate your insight.
Thanks in advance.
James
