Piston Arm?

[MrLarkins]

Question 1: What is this part called?

Question 2: Mine has about 3 to 5 mm play left to right, is that normal or excessive?

[Pablo]

Rod. Piston rod.

[MrLarkins]

is it suppose to be tight, or have some wiggle to it?

[misteright1_99]

The technical term for it is "connecting rod"..

[Pablo]

Originally Posted by MrLarkins

is it suppose to be tight, or have some wiggle to it?

Supposed to move with the piston, but have very mininal side to side movement....what ya mean by "wiggle"?

[MrLarkins]

by wiggle, i mean side to side movement...about 3mm to 5mm

[Pablo]

5mm Sounds like a lot - I don't know what the spec is - PM Norman to check this thread!

[Norman]

I have no specs. on these engines but I'm guessing you should be ok. You don't see any metal flakes or metalic particles inside the crankcase do you?
That would be caused by a needle bearing trashing on either the wrist pin or on the crank end of the rod.
what you had outlined in red is the wrist pin end of the connecting rod.
You will have some side to side play on both the wrist pin end and the big end of the rod and as sorry as these engines are made probably some circular twist as well.
It looks like either you have a needle bearing wrist pin or else you pressed out the writ pin bushing.
Are you having a problem or hearing a strange noise with this engine?

[Pablo]

I think the problem starts here:

http://motorbicycling.com/f3/80cc-mystery-1508.html

[Pablo]

Here's the video of his beast:

http://www.oskgaming.com/downloads/video.wmv = 2.79MB