Piston needle bearing keeps failing.

B

borntofli

Member
I have 2 bgf engines I use that the bearing fails after 500 miles +- ..The bearings don't fit very tight when new.... I use the bearings from bearingsdirect... What would be a more durable bearing....
 
When the needle bearing fails, it almost always wallows out the connecting rod when it goes. No bearing will last if your rod small end is oversized.
 
Upon closer inspection I found the the wrist pin now has grooves in it where the bearing rides....... I will replace it also and see if I can get some more life out of it...I have about 2000 miles on the 2 engines I use... I should feel lucky they still run strong......

Has anyone used the bearings w/ the metal shell on the outside? I have some of these, but they are just too tight to get in the con rod...... 10x14x15 is the correct bearing, correct????????
 
borntofli said:
I have 2 bgf engines I use that the bearing fails after 500 miles +- ..The bearings don't fit very tight when new.... I use the bearings from bearingsdirect... What would be a more durable bearing....
Click to expand...

I had a BGF motor that had the same issue. It was because of a imperfection in the rod small end. I lost 2 small end bearings before parting out the motor. It had about 800 miles on it. I haven't had much luck with BGF or LEB motors. All of them had crankshaft issues of one type or another. I no longer will buy motors from them because of this.
 
borntofli said:
Has anyone used the bearings w/ the metal shell on the outside? I have some of these, but they are just too tight to get in the con rod...... 10x14x15 is the correct bearing, correct????????
Click to expand...

Yes, I messed with these. I needed to use a vice to force the unit into the small-end. I went through two of them and gave up. They fit well over the pin giving smooth performance, and great for "warning" you that they're going bad (clicking-sound before they have a chance of deteriorating, and destroying your top-end), but I only got a couple hundred miles out of both. Plus, removing the sheath is more trouble than it's worth; you need to Dremel it out. In fact, I damaged a crank doing it; if I DO use that crank again, it'll be as a reserve AND I'll have to use my last HK1014 since there's a decent divot on the OD surface. I've been on a pretty good tear on my present standard needle-bearing; the clearances are tight all around and after about 1000mi, it's all still like-new. I'm just really gun-shy about destroying another jug/rings set (you can always grind a piston back into shape!). I'm tempted to try screwing around with brass-bushings now.
 
Kioshk said:
Yes, I messed with these. I needed to use a vice to force the unit into the small-end. I went through two of them and gave up. They fit well over the pin giving smooth performance, and great for "warning" you that they're going bad (clicking-sound before they have a chance of deteriorating, and destroying your top-end), but I only got a couple hundred miles out of both. Plus, removing the sheath is more trouble than it's worth; you need to Dremel it out. In fact, I damaged a crank doing it; if I DO use that crank again, it'll be as a reserve AND I'll have to use my last HK1014 since there's a decent divot on the OD surface. I've been on a pretty good tear on my present standard needle-bearing; the clearances are tight all around and after about 1000mi, it's all still like-new. I'm just really gun-shy about destroying another jug/rings set (you can always grind a piston back into shape!). I'm tempted to try screwing around with brass-bushings now.
Click to expand...

I ordered two of the brass bushings from juicemotors, I plan to try one in my oldest engine when I have time to pull the top end down, it has a little over 2000 miles on it now and has been a very good little engine, its a 2009 engine from BGF and I've notice what seems to be a bit of a rattle up top, not sure if it is an issue pr just more noticable with the quieter exhaust I have on it right now, it is parkered until I can pull the head and jug and do some port work and replace the upper bearing.
Im curious about how the bushing will perform long term.

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One guy told me that when he went to an aftermarket CDI with more spark retard than stock that his bearing problems stopped.
Do you have higher than stock engine compression?
Did you put a better carburetor on it?
 
His bearing problems are still very much still there. Are retarding the timing just quiets down the problem. But bearing failure is inevitable. Running THAT after market cdi is equivalent to a bandaid over a gunshot wound while it wearing earplugs!! Not good.
LMAO
laff
 
I agree. Retarding the timing to cover a quality problem is not the right way to fix this issue.
 
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