Single bearing crankshaft?

I've been looking at two-stroke powered whipper-snippers lately and
was told not to buy the cheaper 'domestic' versions as they have a
single bearing crankshaft. i.e. a bearing on one end of the crankshaft
only. I never heard of such a thing. I spent the extra $50 and bought
the two-bearing model.

Anybody tell me how a motor with only one bearing on the crank stays
together or am I misunderstanding what three different people are
telling me?

Theo

 

Can't believe the crankshaft wouldn't be supported at both ends.. *gasp*

But maybe just a simple bush/sleeve bearing? whereas the other end (the
'drive' end) might have a roller/tapered roller...

 

If I hadn't thrown out the "what ever the brand was" stroker
whipper-snipper, I'd send it to you.

I'm sure you've got enough rubbish about your place, I know I had!

Hammo

 

"Stevo" wrote

*gasp*

Me either.

Like a '50's BSA or Triumph twin?

Theo

 

*pass*


but I am also astounded.. how the hell do they seal the cranckcase to make
it work??

 

Yep, they ran plain bushes.. most serious owners replaced them with
rollers.. plenty of kits available.. did wonders for the oil pressure I
seem to recall, particularly over a reasonable distance..

 

"Stevo" wrote

They blocked off the oil feed on the left side bearing? I thought
(long time since I looked at one) that that feed also went to the
camshaft bushes.

Theo

 

"Theo Bekkers" wrote

Better make that right side.

 

Theo Bekkers wrote:

No thanks....I _gotta_ get a better offer than that! ;-)

regards,
CrazyCam

 

Yes, I think that was the case, fitting the roller bearing outer race
blocked off the opening I think, providing more flow to the top end.. but
on the A10's at least, it was possible to provide a passage from the relief
side of the oil relief valve to the new roller (a drilling, in the right
place) so that once the oil got to the max pressure (50 PSI?) the bearing
was first to get a squirt.. otherwise it just relied on oil splash..

 

I have a perfectly good 2 stroke whipper snipper that i f#*ked the carby on,
as the needle had seized and i tried to pull it out but it broke...

so if anyones got a whipper snipper carby that is just lying around
cluttering up the shed, i would take it off your hands <<< wonders how many
whipper snipper carbys there would have to be to create an appreciable
'clutter'

HEY THEO watch out for carby needle seizure in your new machine...I usually
run the lawn mower carb empty to avoid having this happen, if i ever get the
whipper snipper going, or get another, i'll fit a fuel tap so i can do the
same


Someone let Theo Bekkers at loose on an internet
connection and the result was:

 

I have an old two-stroke whipper snipper that I haven't been able to
start for years. Forget the brand. The new one is a Stihl. The old one
is still.

Warranty, dealer.

Theo

 

The other side has a seal but no bearing (?)

Two seals and one bearing!

Sounds like a good joke. "there was these two seals and bearing walk into a
bar. Boom Tish."

Nathan

 

building materials: "bearing seat", "getting my bearings",
"your round!", "you look like you've been blown by a penguin"

-----sharks

 

There may be bolts holding it together.. but a 2 stroke crankcase needs a
gas tight seal to work properly doesn't it?.. at least a whipper snippre
doesn't have a gearbox to scavenge oil from..

 

Like I was telling Theo, I chucked all that stuff. Had a small collection
of carbies for small stroker engines. Not much use telling you that, but
its always the way, as soon as you chuck it, it comes in handy....

Hammo

 

On 19/9/03 11:36 PM, in article

What about where the cam chain goes. Its runs off the same bearing!

 

"Rex Turner wrote

Find some tall grass and push-start it.

Theo

 

About the only way I believe - you see most motors of this type have an
output shaft one side (for the cutting disk etc and on the other side is
mounted the Fan and the Starter (either Cord or Impulse).
In quite a few years of engineering/repair of most types of motors I can say
the only single sided cranks were in model aircraft motors. So if this
particular motor is also a single sided crank, I'd be interested to see it.

RexT.

 

"Rex Turner wrote

see it.

Rex, I started this thread because of a whipper snipper. The Stihl
dealer told me the difference between two models was that one had a
bearing on one end of the crankshaft and the other one at each end.
They both had pull-starts. I didn't ask how the single-bearing model
worked. I bought the other.

Theo