frischtr
Silver Member
Engine is a Robin EH72D 25hp gasoline V-twin.
I was out mowing grass for the first time this year, and after about an hour of mowing the engine lost power all of a sudden, and dramatically at that. I've been running it all winter moving firewood and plowing snow, so its not a winterizing issue with the fuel. Also, today was rather chilly at about 45 deg. out, so I'm not thinking it was overheated. I've cut grass for hours in 90+ deg. heat with no problems before.
First pulled spark plugs, one was dry and tan, the other darker, but dry. Check spark, both looked good. Did compression check, one cylinder good, one has 0 compression. Pulled valve covers, everything looks normal. Stroked engine and watched rocker arms, also appear to function normally. Also, there is oil backing up through the carb, leading me to believe that I have lost a head gasket. Or maybe one of the valves is sticking, despite the action looking normal.
All maintenance has been performed as required, and the machine only has 70 hours on it (purchased April 2010). What else should I try before tearing it apart? Thanks in advance.
I was out mowing grass for the first time this year, and after about an hour of mowing the engine lost power all of a sudden, and dramatically at that. I've been running it all winter moving firewood and plowing snow, so its not a winterizing issue with the fuel. Also, today was rather chilly at about 45 deg. out, so I'm not thinking it was overheated. I've cut grass for hours in 90+ deg. heat with no problems before.
First pulled spark plugs, one was dry and tan, the other darker, but dry. Check spark, both looked good. Did compression check, one cylinder good, one has 0 compression. Pulled valve covers, everything looks normal. Stroked engine and watched rocker arms, also appear to function normally. Also, there is oil backing up through the carb, leading me to believe that I have lost a head gasket. Or maybe one of the valves is sticking, despite the action looking normal.
All maintenance has been performed as required, and the machine only has 70 hours on it (purchased April 2010). What else should I try before tearing it apart? Thanks in advance.
