Yammie 50hp crankshaft rebuild question.....

[fofiveoh]

After a little searching, I decided to send my little 3 cylinder pressed crank to Bill Bune in MN to have it disassembled so bearings could be replaced. Came back with bearings that do not have the rubberized outer races, but i figure a little 609 should take care of that. Bearings were unshielded though, and i am not sure about that. Original bearings had shields on top sides. What do you think?
Thanks!

[Fastjeff57]

Shields are not needed except with grease lubrication and may prevent oil getting to the balls.

Jeff

[Fast Fred]

need a pic of it

[fofiveoh]

Attachment 59638

No photo, but hopefully I figured out how to attach diagram so you get the idea. I assume that they are there to prevent any trash (not sure where the trash would come from) from falling into the bearings. Original bearings can only receive lube from bottom. THe original bearings also had the "rubberized" stripes to prevent the outer raced from spinning. I feel pretty good that 609 Loctite retaining compound should take care of this, do you agree?

Fast Fred, I just recently found this website, and it seems that you are one of the kings of these little motors. She's not a racer, just a fishing motor. But since its apart, I may try to get a few more HP if its a no brainer. I have several questions...If you answered even a few of them I would be most appreciative!

What is safe max RPM to run 91 pump gas w/ 10% ethanol? Book says 5000-5500. Stock, she is propped to run about 5700 with boat empty now, 5400 boat loaded.

Have learned that I can simply cut off a couple inches from tuner to gain a few....Stupid question, but is it gonna be a lot louder?

Heads are stock with plugs in center (2006). Do you have a rough number that I can shave off that will put me in a range where I can still run crappy 91 pump gas and be reliable? I can recut squish band if needed, but If I can shave some off without it, that would be great.

what is a good minimum squish clearance & good compression PSI for pump gas?

Oiler - is it safe to leave it on there, or should I just start mixing fuel? I like the ease of the autolube, but am happy to get rid of it if it is problematic. Should I incorporate a "plug" to fill the void if I remove the shaft, or is a cover for the hole good enough?

Sorry to bombard you....Have been asking these questions on the wrong website I think, and haven't got any real solid answers yet. I know that Hydrotec sells the head / tuner kit to get a quick 10 HP for these. If I can get that or close to that without spending a bunch, I would be just tickled.

Thanks a million!!

[Fast Fred]

i allways chucked the oiler, if ya can make a filler plug or leave the gear-shaft in side and put a cover over it. don't take the crank gear off. just clean any misalignment in the ports, leave the cyl alone, just the aluminum, 145psi is good for pump juice. squish band, you need to take a squish measurement to see were she is, you may not have to think about it............
let it spin

[Fast Fred]

i don't think i would cut the tuna, i would mill on the gasket end to get the squeeze closer..................... as long as you leave the muffler box alone she won't be loud.