Frankenstein
Deceased - Frankenstein 1991 - 2018
- Local time
- 8:13 AM
- Joined
- Jun 24, 2016
- Messages
- 5,035
Well, first time posting on this forum (or any motorized bicycle forums, for that matter,) so I'll give the back story of my bike(s). Around the same time last year, I picked up a cheapo 150 or so dollar happy "go lucky or broke" time engine from that Gasbike site, worked beautifully as a single speed set up. Then later on, I got my shift kit, from sbp, put that and the original engine into a mongoose terrex. Well as time went by, I broke my crankshaft, twice, picked up a ported cylinder and piston to match, and a Reed valve, even made custom turn signals and headlamp, rear light and waterproofish box to hold the whole thing to run it.
Now recently, after my crank was damaged a second time (bevel gear was loose, ended up shearing the key, and turned it into a grinding paste, destroying the taper and preventing a gear from being pressed on tightly, all my fault because I figured "it'll be OK till I get around to it" not!) Anywho, damaged crank, decided to rebuild, put it together, reused my main bearings, figured they were OK, and after a month of in-between repairs, the bearing seized in under 24 hours, on the second time I rode it. Now, spent a week or 2 re-repairing, and new bearings, brand new! They are already failing, making lots of bad evil sound and sticking, making the engine stall on idle, with the idle screw full on tight. And stopping it in general. Here's the interesting part. My crankcase is 2 different engines. Left side is from my original, right side is a different engine, one that blew up on the top end, the crankshaft was in that engine, but good condition otherwise. Also I find that pressing the bearings onto the crank was a little harder than I remember last time, and getting the engine cases together required quite a bit of tapping with a 16 oz hammer, then torqueing the case bolts down to finish the press. So, are the bearings supposed to be a tight fit on the crankshaft arms. And after pressing the crankcase together should turning the crank over be resistive. And finally, could having 2 different halves, being that they probably came from opposite sides of China, be a bad thing, making for misalignment, and resulting in early bearing failure, the bearings I originally had in the original engine were perfect considering they had nearly 8 months on them, and practically no air filter. Also worth noting, the engine case with the crankcase that make up 2/3rds of the trio when opened to check things out, had a failed main bearing, same side that it failed on recently, and probably the same failing yet again (I have not opened it yet, it's still installed on my bike, and only began failing yesterday.) Oh and since I'm mentioning things, right before the bearing failed the first time, the engine started making a whirring sorta sound, got louder, then failed, this one did the same exact thing, but I also installed a new (old beat up) large 2 and a half gallon motorcycle engine, from a vintage suzuki ts125 or ts185, it has a very small leak and drips gas right on the hot engine head, shouldn't be the source of the problem though. The reason I mention it is I can't tell if the tank makes more sound as it gets empty, as in as the gas is used, creating more empty space and exposed metal to vibrate and make that sound louder as it gets even more empty, get it?
Anyways, sorry for the way too long novel, but I tend to write in novels rather than paragraphs. Thanks for input when it comes.
Now recently, after my crank was damaged a second time (bevel gear was loose, ended up shearing the key, and turned it into a grinding paste, destroying the taper and preventing a gear from being pressed on tightly, all my fault because I figured "it'll be OK till I get around to it" not!) Anywho, damaged crank, decided to rebuild, put it together, reused my main bearings, figured they were OK, and after a month of in-between repairs, the bearing seized in under 24 hours, on the second time I rode it. Now, spent a week or 2 re-repairing, and new bearings, brand new! They are already failing, making lots of bad evil sound and sticking, making the engine stall on idle, with the idle screw full on tight. And stopping it in general. Here's the interesting part. My crankcase is 2 different engines. Left side is from my original, right side is a different engine, one that blew up on the top end, the crankshaft was in that engine, but good condition otherwise. Also I find that pressing the bearings onto the crank was a little harder than I remember last time, and getting the engine cases together required quite a bit of tapping with a 16 oz hammer, then torqueing the case bolts down to finish the press. So, are the bearings supposed to be a tight fit on the crankshaft arms. And after pressing the crankcase together should turning the crank over be resistive. And finally, could having 2 different halves, being that they probably came from opposite sides of China, be a bad thing, making for misalignment, and resulting in early bearing failure, the bearings I originally had in the original engine were perfect considering they had nearly 8 months on them, and practically no air filter. Also worth noting, the engine case with the crankcase that make up 2/3rds of the trio when opened to check things out, had a failed main bearing, same side that it failed on recently, and probably the same failing yet again (I have not opened it yet, it's still installed on my bike, and only began failing yesterday.) Oh and since I'm mentioning things, right before the bearing failed the first time, the engine started making a whirring sorta sound, got louder, then failed, this one did the same exact thing, but I also installed a new (old beat up) large 2 and a half gallon motorcycle engine, from a vintage suzuki ts125 or ts185, it has a very small leak and drips gas right on the hot engine head, shouldn't be the source of the problem though. The reason I mention it is I can't tell if the tank makes more sound as it gets empty, as in as the gas is used, creating more empty space and exposed metal to vibrate and make that sound louder as it gets even more empty, get it?
Anyways, sorry for the way too long novel, but I tend to write in novels rather than paragraphs. Thanks for input when it comes.