Home › Forum › Ask A Member › Unburned Fuel collection › Re: Unburned Fuel collection
I have a 1976 20 Mercury that had a bad lower crank bearing – I found one cheap at a local bearing house that was same dimensions but was a sealed bearing. I stupidly put it in and partway through the 1st tank of gas, it started running really bad – like on one cylinder. I haven’t taken it apart yet, but checked carb, spark, etc – all OK. If I remember right, I think the tube that scavenges gas from the bottom of the crankcase , putting it in again up higher, is picking up nothing now because gas has to get through the lower bearing that is not supposed to be sealed. So I think unburned gas is pooling in the lower crankcase until it rolls into the intake port. That was several years ago and maybe some day I’ll get to tearing it down again…I hate that motor, from the day I got it, something new broke every time I ran it – but it did have mega-hours on it before I got it. I had to replace a piston because of balls from the lower bearing being sucked into the lower cylinder and beat up the piston top pretty bad!
Dave