wrist pin needle bearing lubrication holes

My first enguine was rattly since new- never got worse, still running as far as I know (sold it a year ago) the guy never came back, and I told him to if he had questions or problems.
 
My engine is still getting better, seems like bottom end torque has gone up as it further breaks in. If it doesn't grenade, it should last some number of years.
 
Customers often don't understand why I put 50-100 miles on a new bike/engine before I sell it to them. The difference in power is the main reason as well as differences in ease of starting and overall engine operation on a new engine and one that is slightly broken in is noticeable.

One new engine recently, wouldn't go faster than 15mpg unless I was going down hill. It took dozens of repeated short trips at varying throttle settings to finally get those rings to seat. Its up to 21 mph after 18 miles and should top out at 25mph.
 
update on build

I never ended up getting that hole drilled all the way through so I replaced the roller bearing with a solid brass*?* bushing from livefastmotors. I am also running oil with 20% castor oil.

Thanks for all the ideas.

A theory for one of the failure modes of the roller bearing is that it might "walk" on the wrist pin and become off-center, then fail.

The bike is running well and so far has about 4 hours. I need to figure out which type of front brake will fit and order that.

Here's the bike:
sunmotorizedbikesideview.jpg
 
Here is some pictures of my work in progress. Thing is the bushing on the wrist pin did not look bad in the first place. I just have some little marks or scratches on the cylinder walls, but not much. It's kind of like some crome pealed off or something that is where the red arrow is pointing to. Just a little spot and a little scratchy in another black arrow. I guess I will sand the area down where the bushing was and go with another bushing. Did a compression test was at 120 lbs and after 1/2 hr it was 118 lbs.
149qgyc.jpg

2wf21rk.jpg

2chm96t.jpg

2rcrcyh.jpg

Sand off the old bearing surface with some fine sand paper.
 
Last edited:
How did you press your new bearing in? Don't want to smash it. Sould be able to pick up some breaks on e bay.com. also my little cardboard gasket on the bottome riped in two, wonder if anyone knows if that regular stuff you get at Autozone that is on a role like tar paper should work right?
 
Last edited:
Wow! That cylinder wall doesn't look too healthy...but you have good compression and it holds.

Where did you get the bushing?
 
sisdavid said:
How did you press your new bearing in? Don't want to smash it. Sould be able to pick up some breaks on e bay.com. also my little cardboard gasket on the bottome riped in two, wonder if anyone knows if that regular stuff you get at Autozone that is on a role like tar paper should work right?
Click to expand...

The bushing went in perfectly for me in the table vice. Con rod was against vice, board between vice and bushing. I held the parts with one hand and spun it into place with the other.

I used the autozone roll to regasket head and intake manifold, no issues so far (6.9 hrs). That permatex gasket shellac helps seal it too.
 
I used Tinypic.com for the photos someone on here told me about them. I am going to use it for other things. I think I am going to change my mixture up to 5oz a gallon instead of 4oz, those marks look rough, but the only ones you can feel are the ones with arrows. Ya know if anything the bearing in the bottom had play in it not much but a little.
 
More pictures here is my compression. and some others Should I clean this black stuff off of my head and if yes with what, can do anything else kind of important while I have it appart, and finally, The bottom bearings appear to be needle bearings is this right? I can kind of see a little crome thing go buy through oil hole when spinning the engine, and should I drill another oil hole through my wrist pin for more oil?

s48bqw.jpg


180tqf.jpg
 
Clean the carbon off. Don't use anything metal or sharp to do it.
Torque the head down so it is not leaking.
Mix your fuel at 24:1 maximum.

If you do drill an oil hole, just clear the burr off the inside of the bushing before reassembly.
 
sisdavid said:
How many Ounces a gallon would that be?
Click to expand...

128 oz = 1 gallon

1:128 1 oz oil
1:64 2 oz
1:43 3 oz
1:32 4 oz
1:26 5 oz
1:21 6 oz
1:18 7 oz
1:16 8 oz
1:14 9 oz
1:13 10 oz

All rounded.

So 24:1 = 5.33 oz oil
 
You must log in or register to reply here.
Back
Top