Originally Posted by
wingracer
I said so what because it doesn't matter. It is a very common misconception that the front bearing actually seals the engine. It does NOT. You could run a bearing with no seals and it would run just fine (onroad motors are like this). The only reason for the seal is to keep the dirt out.
I think the reason OS motors leak more than some others is due to their different design of the oil groove and the little hole that sucks out this oil. To see what I mean, pull the bearings from an OS and a Nova case and take a look down in there. There is a thread in the engine zone that talks about this, I will post a link in a minute.
Can you elaborate on why the front bearing can be open and not matter? I'm curious because:
1) I've sealed my carbs and backplates. I also did it for a friend, which made a big improvement in the consistency of his engine's operation. His engine just wouldn't run right before I did so. I realize carbs and backplates are not front bearings, it just seems to me to go hand-in-hand.
2) I had an RB that leaked fuel badly. It was pooling in my chassis and, in hindsight, the runtime was terrible. I was a total n00b at the time, so I took my buggy to a LHS. He took the flywheel off and showed me that the front bearing seal was gone. They replaced that bearing and the problem was gone. If the front bearing can be completely open and operate fine for on-road, do they have a problem with fuel loss?
Thanks in advance.