Upper needle bearing failure...

GoldenMotor.com

borntofli

Member
Jul 27, 2012
306
0
16
tx
Have had 2 engines in the last week w/ upper bearing failure....They both have 700-1000 miles on them......

I knew they both were going, could hear the piston slopping around more than usual...

I replaced them with bearings from bearings direct... Hope they are better quality.....

Anyone else have troubles???

I'm running amsoil 50-60:1 and everything else looks fine......
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
been discussion here about needle bearings that are too short & need spacers added to hold them centered in the rod, others seem to be long enough

search this forum a bit
 

Kioshk

Active Member
Oct 21, 2012
1,152
10
38
Connecticut
Try out an HK1015. You can find 'em on eBay for like $8 delivered. They're wider than the stock bearings. I put one in my baby, and it's humming along well. The needles are encased, so there's less chance of them polluting the crankcase on failure. I believe their being encased aids in retaining oil around 'em too. I inspected the bearing after about 500-miles, and it looked and behaved like new.
 

Kioshk

Active Member
Oct 21, 2012
1,152
10
38
Connecticut
Note on placing this bearing in both GT5 & X80 engines: it's a TIGHT fit. I used a rubber-mallet to tap it in to the crank. The bearings ride smoothly however as the track does not deform considerably due to compression.
 

borntofli

Member
Jul 27, 2012
306
0
16
tx
Pulled my other one apart that was starting to rattle the piston a bit... The bearings fell out as I pulled the pin out... No damage.....Whew.....

I pull a trailer alot so I put a load on alot.... My 3rd bike that is just a cruiser doesnt have the piston clanging problem yet... I will riplace the bearing anyways.... They run so smooth w/ new bearings....
 

Toadmund

New Member
Jan 19, 2012
792
6
0
Saint John, New Brunswick, Canada
I have a question that needs an answer:
I read an old post started in 08 that mentioned bushings were 11mm ID and needle bearings 10mm ID, my motor I bought a year and a 0.5 ago was manufactured in 09, I think this was a time when Flying Horse engines were changed over to needle bearings, the wrist pin for bushings is 11mm and needle bearing bushings are 10mm.

I have an 11mm (possibly 10.3, 10.4mm) wrist pin with a needle bearing. A 10mm won't fit.

If I needed to replace this bearing, what size do I need to get?
Almost seems like this needle bearing doesn't exist or is propriatary or is not made anymore.