imported_Paul_H
Seaman Apprentice
- Joined
- May 1, 2003
- Messages
- 35
Re: V4 140 OMC Leaking crankcase - JB WELD??
The air bypass holes and idle holes in the butterflies are designed to work with the carburation of the engine.<br /><br />It doesn't take much air to change from properly carburated to lean. O/b's aren't as critical to carb as highly tuned race engines, but from my experience racing two strokes, it doesn't take much tweaking on the jets to go from just right to too lean. You are going about it the opposite way by adding air to the mix.<br /><br />Think of it this way, your other 3 cylinders are all being properly carburated, but the one cylinder with the leak will be running lean, as it is being carburated differently, specifically, leaner. Internal combustion engines, especially two strokes have a narrow range of air fuel mix that produces proper burning. Two much fuel and a two stroke sounds like a 4 stroke, too little fuel and the engine overheats.<br /><br />I can understand using a quickie fix if I found the leak on a trip, and needed to get back to shore, but can't see running the engine in its condition, especially after the time and $ you put into rebuilding it.<br /><br />Think about this, would you run the engine with a falty water pump? Would you run the engine with a falty oil injector? If no to either question, then consider your crankcase leak as just as critical.<br /><br />Be thankful you've found the leak and can fix it before damaging the engine. Much better then burning up that piston, then finding the leak.
The air bypass holes and idle holes in the butterflies are designed to work with the carburation of the engine.<br /><br />It doesn't take much air to change from properly carburated to lean. O/b's aren't as critical to carb as highly tuned race engines, but from my experience racing two strokes, it doesn't take much tweaking on the jets to go from just right to too lean. You are going about it the opposite way by adding air to the mix.<br /><br />Think of it this way, your other 3 cylinders are all being properly carburated, but the one cylinder with the leak will be running lean, as it is being carburated differently, specifically, leaner. Internal combustion engines, especially two strokes have a narrow range of air fuel mix that produces proper burning. Two much fuel and a two stroke sounds like a 4 stroke, too little fuel and the engine overheats.<br /><br />I can understand using a quickie fix if I found the leak on a trip, and needed to get back to shore, but can't see running the engine in its condition, especially after the time and $ you put into rebuilding it.<br /><br />Think about this, would you run the engine with a falty water pump? Would you run the engine with a falty oil injector? If no to either question, then consider your crankcase leak as just as critical.<br /><br />Be thankful you've found the leak and can fix it before damaging the engine. Much better then burning up that piston, then finding the leak.
<br /><br />c/6<br /><br />Hooty