Confused

[gary55]

I ain't screwing with the big end either. What a pain. Truth is even though their is the slop at the top the damn things still work pretty darn well.

 

[FurryOnTheInside]

I was talking about the bottom end slop, idk about anyone else!
The rod can move a frightening amount walking and/or tilting side-to-side. The rod is very loose on the bottom end bearing as I've seen when the top end of my eBay engine was dismantled. In comparison, the piston doesn't tilt side-to-side much when it's on the rod.
So I think the top end bearing is taking the strain of keeping the rod vertical all on its own. I feel like it would be better if it wasn't.

 

[gary55]

I was talking about the bottom end slop, idk about anyone else!
The rod can move a frightening amount walking and/or tilting side-to-side. The rod is very loose on the bottom end bearing as I've seen when the top end of my eBay engine was dismantled. In comparison, the piston doesn't tilt side-to-side much when it's on the rod.
So I think the top end bearing is taking the strain of keeping the rod vertical all on its own. I feel like it would be better if it wasn't.

The distance form the wrist pin to the top of the piston is far less than the distance from the bottom to the top of the rod so the rock is naturally going to be more exaggerated even with the same tolerance. It does seem like a lot of play in both cases. Still I'm no engineer and these engines seem to run for a long time like this.

 

[FurryOnTheInside]

The distance form the wrist pin to the top of the piston is far less than the distance from the bottom to the top of the rod so the rock is naturally going to be more exaggerated even with the same tolerance. It does seem like a lot of play in both cases. Still I'm no engineer and these engines seem to run for a long time like this.

I was mentally taking that stuff into account, it does seem like the tolerance is worse at the "big end" (bottom of the rod). I am not an engineer either, I just feel like it adds to the chances/frequency of little end bearing failure by making it do all the work.

Are the Zeda big end bearings as sloppy as the eBay/Happy Time big ends?

I would much rather have a Zeda or Skyhawk anyway. Even though I have learned a lot and had some "fun" fixing up the eBay crappy time engine as a hobby and a way to really get to know the workings of a 2-stroke engine, I wouldn't want to do it all over again tomorrow! Too much work.

 

[HumanPerson]

Well here's how I see it, if I were you I'd of figured if he was all in, part in, or really not for it at all and wouldn't be buying a kit anyway. So all in is willing to learn, and part in is just looking to put a bike together with a motor and go looking to die with it unintentionally.

The part in's and not for it's I will basically shrug off with the information that you can buy them on eBay, simple as that and I prefer not to help, I am a busy person after all.

The ones who are willing to learn and understand I kindly offer any help I can to.

If he's still willing then disregard his father's banter as his son will do it equally so since if he's willing to learn then he's in it enough to willingly disobey his father. Teach him what is obviously most important, and also explain that the 88 dollar kit cannot compare to a better quality kit no matter what you do unless it involves throwing the kit in a garbage can, I'm certain you've done that part already.

Now observe, if he's acting like a fool then let fools be what they are, he would have gotten the kit anyways and without your help if he is very inept and he gets it running then he'll have it die soon enough and be unable to fix it. No problem.

Really there's a point where you should ask yourself if a person would be off any differently at all if you had met them a month later than you did. To me a 17yo kid with a father in a wheelchair and probably no car is probably itching to get on/in anything with an engine, so I would bet after seeing you and any number of other people with one he'd of come to own one anyway.

So if you think he's worth teaching, teach, if he's on a path to recklessness and it was inevitable anyways then you may want to step back and get uninvolved, the more days between you last seeing him and the day he gets flattened by a semi the less chance you'll get caught up in any nets and less you'll feel affected by his death regarding a guilty conscience/natural human bonding.

Use your best judgment in other words.

Yeah we think alike sometimes.
I spoke to them again today and i have come to the same conclusion as you.
Let him become pavement burger.
I'm stepping back from this kid and his father.

Sad really, but.. can't change stupid.

Thank you all for your comments, now carry on!

 

[Frankenstein]

Well... The rod is being pressed upon from 2 sides, both of which are parallel objects so even with wiggle room the rod should be forced vertical by compressive and pulling forces. I would see any wiggle that allows you to go out of vertical is technically empty space between the races and rollers, in this case that means the rod can chatter on the bearing and repeatedly crush it or otherwise hit it and create flat(er) spots. That quickly pronounces you man and wife and it fails in short order.

If it's only capable of lateral movement with barely a hint of wiggle out of vertical then I don't think I would be nearly as concerned, you need a tiny bit of room for things to heat up and expand without putting too much strain on the bearings. I don't know how I feel about the no name bottom end bearing but I haven't addressed them even once and still haven't had any problems relating to them, so I guess I'll keep taking my chances lol.

 

[gary55]

I was mentally taking that stuff into account, it does seem like the tolerance is worse at the "big end" (bottom of the rod). I am not an engineer either, I just feel like it adds to the chances/frequency of little end bearing failure by making it do all the work.

Are the Zeda big end bearings as sloppy as the eBay/Happy Time big ends?

I would much rather have a Zeda or Skyhawk anyway. Even though I have learned a lot and had some "fun" fixing up the eBay crappy time engine as a hobby and a way to really get to know the workings of a 2-stroke engine, I wouldn't want to do it all over again tomorrow! Too much work.

I guess we are living proof that a degree isn't needed to recognize a design flaw when seen. I have never had a ebay engine. Those that I have seen were used so can't really comment on the bearing slop. I do know some wobble exists in all from skyhawk to gas bike to black stallion to to Zeda and all seem close to the same.
I am really more concerned with the walk on the wrist pin than the big end. At least the wrist pin bearing that you have that has a larger casing will restrict its movement so even thought the pins themselves are the same size they can't exit the rod as far so their will always be more of them bearing the load.

 

[gary55]

Well... The rod is being pressed upon from 2 sides, both of which are parallel objects so even with wiggle room the rod should be forced vertical by compressive and pulling forces. I would see any wiggle that allows you to go out of vertical is technically empty space between the races and rollers, in this case that means the rod can chatter on the bearing and repeatedly crush it or otherwise hit it and create flat(er) spots. That quickly pronounces you man and wife and it fails in short order.

If it's only capable of lateral movement with barely a hint of wiggle out of vertical then I don't think I would be nearly as concerned, you need a tiny bit of room for things to heat up and expand without putting too much strain on the bearings. I don't know how I feel about the no name bottom end bearing but I haven't addressed them even once and still haven't had any problems relating to them, so I guess I'll keep taking my chances lol.

I hadn't thought about the heat factor. Makes sence.