"I'm new to the forum and
"I'm new to the forum and fairly new to boat ownership in general. I recently bought a boat with an '03 yamaha 75 hp 4 stroke. I had carb problems (engine wouldn't idle - and eventually wouldn't start) after storing it for the winter. I had the carbs overhauled at a local shop and after the repair I drained the gas and replaced the fuel filter. I've had the boat out a couple of times now since the carb overhaul. The motor runs great when wide open but not so great when I come down to idle speed while still under power. It doesn't die on me but you can definitely tell the motor is shaking and struggling like it's about to quit. However, when I put it in neutral the motor smooths out and idles fairly well. To add to my concern, as I jump into and out of gear as I idle from crab pot to crab pot I start to smell oil burning and see blue smoke in the exhaust. In fact, when I give it a quick burst of gas to get around a pot the motor disappears in a cloud of smoke and my passengers cover their noses with their shirt sleeves. If I give it full throttle and zip down the bay at top speed I don't see or smell any oil burning. I come back to idle and putt around for a bit and then I get the smoke and smell of oil burning again. So after all this: At low rpm is there a chance that oil is leaking from the valves or rings - a quick run burns it off - only to accumulate again at low rpm? Or am I burning oil at all speeds and will probably need to re-build the head? A carb overhaul wouldn't be connected to this problem would it? Thanks in advance for any of your insight/advice."
"I'm new to the forum and fairly new to boat ownership in general. I recently bought a boat with an '03 yamaha 75 hp 4 stroke. I had carb problems (engine wouldn't idle - and eventually wouldn't start) after storing it for the winter. I had the carbs overhauled at a local shop and after the repair I drained the gas and replaced the fuel filter. I've had the boat out a couple of times now since the carb overhaul. The motor runs great when wide open but not so great when I come down to idle speed while still under power. It doesn't die on me but you can definitely tell the motor is shaking and struggling like it's about to quit. However, when I put it in neutral the motor smooths out and idles fairly well. To add to my concern, as I jump into and out of gear as I idle from crab pot to crab pot I start to smell oil burning and see blue smoke in the exhaust. In fact, when I give it a quick burst of gas to get around a pot the motor disappears in a cloud of smoke and my passengers cover their noses with their shirt sleeves. If I give it full throttle and zip down the bay at top speed I don't see or smell any oil burning. I come back to idle and putt around for a bit and then I get the smoke and smell of oil burning again. So after all this: At low rpm is there a chance that oil is leaking from the valves or rings - a quick run burns it off - only to accumulate again at low rpm? Or am I burning oil at all speeds and will probably need to re-build the head? A carb overhaul wouldn't be connected to this problem would it? Thanks in advance for any of your insight/advice."