Happt Time factory assembly - No wonder these engines keep failing

Fabian

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Holy heck - now i understand why these 2-stroke chinese engines keep failing.

Bashing things into place with a hammer isn't exactly the correct assembly procedure.
I made up a jig that screws into the 6mm crankshaft thread that allows the helical crankshaft output gear to be evenly pressed into place.
I think that's why a good portion of these engines make so much gear noise - a slight amount of lateral movement is going to cause incorrect gear mesh.


http://www.youtube.com/watch?v=U6ZfkS20oYI
 
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what did you expect... Ferrari precision??? That video is pretty much what I had in my head....

Could be why grubee's tend to last a little longer... he personally visits the factory and approves the production process and quality controls of all the manufacturers that put out his engines.
 
*Yawn* This video has been around for a while. With various importers trying to discredit other importers on "crude" manufacturing techniques.

What I see is a person driving in a crank seal, with a seal driver and a hammer. I don't see anything unusual about that.
 
Ferrari precision is not to be expected but bashing in a crankshaft seal with the face of a hammer is totally unacceptable.

How hard would it be to weld a bottle jack upside down with a limit stop and a correctly sized driver to press the seal into place.

It's well within the bounds of third world technology.

Fabian
 
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Ferrari precision is not to be expected but bashing in a crankshaft seal with the face of a hammer is totally unacceptable.

How hard would it be to weld a bottle jack upside down with a limit stop and a correctly sized driver to press the seal into place.

It's well within the bounds of third world technology.

Fabian

I see you corrected yourself on the part being installed. It is clearly a seal and not a gear, like you previously posted.

It is being driven in with a production tool.

Have you ever replaced a seal on an engine before? If you have, you'd know that they are driven in with a hammer.
 
You DO get what you pay for with these kits. You can't expect much with a $99 kit on a $69 bicycle.
 
I've rebuilt the engine currently in my bike making a few modifications along the way.

To press the crank seals into place i used a suitably sized socket and a large G-clamp to press the seal into place.
No bashing the **** out of it with a hammer - i'll leave that for the Chinese factory.
 
I've rebuilt the engine currently in my bike making a few modifications along the way.

To press the crank seals into place i used a suitably sized socket and a large G-clamp to press the seal into place.
No bashing the **** out of it with a hammer - i'll leave that for the Chinese factory.

Right - tell the guy replacing the rear crank seal on your Holden to get a "large G-clamp" and press that seal in place.......
 
Right - tell the guy replacing the rear crank seal on your Holden to get a "large G-clamp" and press that seal in place.......

+1, we bang 'em in there like that all the time at the shop :devilish: If at all possible we'll try to put a big socket or something on the seal (old seal can also be used). If space is at a premium, we'll just whack it in there with a good ol' hammer :giggle:
 
I have used sockets, sections of metal pipe, PVC sprinkler pipe, wooden blocks, ect. to drive in seals. Just lube 'em up, inside and out, then drive them in square and true.
I have never had a quality seal fail on me yet *knock on wood*. I have had cheap seals that were too big for the counterbore fail though.
Yes, I also have screw jacks, pilot sleeves ,and proper seal drivers that match the screw jacks. It all really depends on the application.
Get 'er done!
 
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