Uh oh, something broke....

B

borntofli

Member
66 Ht started making a slight banging noise so I peddled home.... Took it apart and see a 1/16" needle bearing part that has been banging between the piston and head.....

where did it come from??? Wrist pin bearing or something lower???

Can I just put a new top end on it and go on?? Hopefully I can shake out any pieces from the bottom that may have made their way there......

Good thing I had a spare engine to replace it with.... Its my only form of transportation.....
 
borntofli said:
66 Ht started making a slight banging noise so I peddled home.... Took it apart and see a 1/16" needle bearing part that has been banging between the piston and head.....

where did it come from??? Wrist pin bearing or something lower???

Can I just put a new top end on it and go on?? Hopefully I can shake out any pieces from the bottom that may have made their way there......

Good thing I had a spare engine to replace it with.... Its my only form of transportation.....
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That I know of there are only four places it could come from
2 pins hold the rings in place, and a needle bearing at top and bottom
of conrod you'll just have to look, does it seem to have done any damage
to piston or cylinder walls? if not replace with new part and go or swap out
part from new engine and order another your choice.
 
Took the cyl off and found the needle bearing has failed.... A few dings on the piston and head.... will replace w/ better bearing and see what happenbs.... I ordered a bunch to upgrade all my engines....
 
Here is something I did, Bought a couple teflon washers, sanded them down and widened the holes to fit my pin. cleaned them up then installed them.
This stops your needle bearing from drifting out witch puts uneven stress on the bearing.

I learned this from another thread, except they used nylon spacers.
 

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The rod has an oil hole, and I believe plenty of oil can get past the teflon rings.
Everything seems OK, I'll be able to see how they are doing next time I take the head off.

Whatever the case, it gives me peace of mind to not worry about bearing drift.
 
After searching this forum for about 30 minutes now, I realised that I read this on another forum!
Don't know if I can link this, but here it is, wavy washers, brass, nylon etc.


Do this and stop worrying about your bearings getting destroyed.
 
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finally had some time to look thru old motors around here - only found one VERY old one that had that gap at the needle bearing on the wrist pin, all others don't need any spacers put in at all

problem must be local to some geographic area or certain vendors I'd guess
 
crassius said:
please post when you find out, as it seems an interesting idea
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Well, I had to take my motor apart, piston and cylinder was damaged, but it was not because of my small end bearing.

I put those teflon spacers in at the beginning of last summer, and here is what they look like now:
 

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Destroyed piston, cylinder; lower piston rod bearings were the cause, but no damage to crankcase bearings, and no damage to my wrist pin bearings, the teflon spacers held up well (may even helped protect them from shredded bearing bits), they did seem to flatten or/and wear a bit, but very minor.

When I rebuild my motor, teflon spacers are going in again, that's for sure.

Now, if only there was a way to improve the reliability of the lower needle bearings?
 
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