Hey fellas.... I just noticed something when I went and changed the engine bearings on my Evolution 26gx After looking this over again and again and thinking to myself is this possible ? why would they do this ? I noticed that there is no stop end on the crankshaft to keep from crushing the two bearing against the front of the engine housing and the back of the crank... hence putting a serious preload on the engine bearings. What I mean is the tighter you go with the prop nut the more preload you put on the bearings and basically crushing the two together.... this seems odd.... isn't that putting why to much stress on the bearings ? I noticed this when I went and tightened the prop nut and could feel the difference in the crank rotation went from smooth spinning to a slight bind and yes the bearings are seated correctly in the block. Ok... so am I nuts here ? I have rebuilt many engines in my 30 plus years of modeling and even in the small nitro engines there is a stop to keep the two bearings from being crushed together.... am I over reacting here ? Input appreciated !

Darryl

No factory mistake, but user error.
You forgot to mount the ground washer disk on the front shaft (between prop drive and crankshaft step. This disk takes the load, not the bearings.

Disregard....

Ok... So... After tossing this around some more I decided to disassemble the engine and rethink the construction.... and now I see how the manufacture figured this one out. What they are doing is butting the second half of the crankshaft up against the rear half of the front bearing inner race and basically using that as a lock so to speak which holds the crank firm and with out end play ( in and out ) While still leaving enough room on the rear bearing so it does not crush. The washer behind the prop hub is basically a spacer to make sure the front bearing inner race is seated up against the second half of the crankshaft. Soooooo.... Yes I was over reacting !!! Case solved.... Sorry Pe !!! Just couldn't see it with out taking it all apart again and looking at it real good.

Cheers !!

Glad you got it solved.
The construction is a bit like the glow engine front drive, where the prop drive cone butts up against the front bearing inner ring. Millions of engines run like tops that way.