New Engine Questions

There's 2 shove tests KC...
#1 is the one you mentioned....
#2 the one where you shove the darn thing HOME...
called the homey test. (carry on)
Hehehe, I am not a fan of the Homey test and why I build the way I do ;-}
 
I'm just a repair shop, so all I see are the mistakes - never seen the cut frame mistake when PVC is used.
 
I'm just a repair shop, so all I see are the mistakes - never seen the cut frame mistake when PVC is used.
I'm presuming this is to correctly match the rear mount radius to the bike frame for full/better contact, rather than any vibration damping properties, so that aluminium strip bent and cut to make a shim should be just as good?
I certainly see the sense in getting as much contact in the mounts as possible. I might have a go at this (with aluminium as I don't even have any PVC pipe) tomorrow when I can be noisy. :)
 
my thinking is that any sharp edge back there will eventually lead to metal fatigue in the frame - even a soft aluminum might create a stress riser there

my preference is hard leather, but that takes forever to pack down nice and solid, so I usually go with the PVC even tho that also takes a couple extra adjustments back there as it forms to both sides of the mount

the frames I see look like they crystallized and just snapped rather than having been cut
 
my thinking is that any sharp edge back there will eventually lead to metal fatigue in the frame - even a soft aluminum might create a stress riser there

my preference is hard leather, but that takes forever to pack down nice and solid, so I usually go with the PVC even tho that also takes a couple extra adjustments back there as it forms to both sides of the mount

the frames I see look like they crystallized and just snapped rather than having been cut
I would certainly round off the edges of the shim, I agree about sharp edges. Idk if I have the right thickness of aluminium plate anyway.. I'll do some test fitting. :)
Personally I would not choose leather as it can rot, swell, hold saltwater, and the PVC sounds fine if I can't do it in aluminium. :)
 
The point is to not have any 'sharp edges'.
You mount the back of the engine metal to metal dead flush with the seat post no matter what because that is the power transfer point!
 
Just bought a new 80cc engine online. Bought it from ebay, its a basic 80cc/66cc (Jet) engine. Ill post a link to the engine on ebay. I Was wondering if you guys have any tips for me regarding break in or assembly. I was thinking about breaking in with Opti2 at 100:1 but open to suggestions. Also, how much assembly is required? Loctite? Replace bolts? Thanks in advance guys!

http://www.ebay.com/itm/162126187665

I would recommend getting rid of all the kit lock washers and buying a better grade. I noticed that after tightening and re-tightening that they flattened out and didn't have much spring to them. I'm sure to save cost they use a low grade of hardware.
To save money I made my own engine mounts using a 2 in dia. x 2 in. DWC Flexible PVC pipe coupling. The wall thickness is about 1/4 in. You can find them in the plumbing dept in a hardware store. I discarded the clamps. Using a hot utility knife I cut the length in half. Then I cut the diameter up in 4 equal sections. I cut out the edges so the studs would fit. While making these mounts you just have to use your own judgement to suit your own needs. The diameters are not the same so I force them into the engine brackets while tightening them together. You may have to replace the studs or lengthen them by turning them out a few turns. Or you can just buy the mount that sell on line for $15.00. Good Luck
 
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Welcome guest Bern Rocks, that is some unreadable run-on post but I managed to get through it.

I suggest you read this entire 2 page topic before posting the absolute worst way to mount an engine.
 
Welcome guest Bern Rocks, that is some unreadable run-on post but I managed to get through it.

I suggest you read this entire 2 page topic before posting the absolute worst way to mount an engine.
I concur KC. Indeed I do Sir. Metal 2 Metal I always say to those who ASK.
 
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