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  1. M

    Bicycle Motor Parts Grab-bag!

    SOLD! Due to some big life changes, I have had to given up my motorized bicycle hobby for the time being. Now that I'm moving, I've got to get rid of everything I have. This has been a fun project and I intend to come back to it one day. Meanwhile, I need to sell off all the bike parts that...
  2. M

    Where to get better crank bearing seals?

    I just got a new 66cc HT, and now that I know better, I'm doing a complete teardown of the motor to do my own quality control. I want to replace the crank bearings with ones that will last longer and tolerate heavy use, and perhaps provide a slightly smoother experience. I noticed that the...
  3. M

    Frankenengine lives, sorta...

    Hey guys. In case you haven't read my other threads, here's what I've been up to. I had to replace the crankshaft in my RAW 66cc engine, but RAW no longer makes or sells the necessary parts, so I bought a crankshaft and piston meant for a grubee, and after installation I added extra jug base...
  4. M

    Bottom end rebuild blues

    After breaking my crankshaft, I finally got a new one and what is supposed to be the correct piston for it. I got my whole engine back together, but before I could even install it, I noticed that the piston was hitting the head. I wasn't too worried about this because I could always add...
  5. M

    Piston doesn't clear the crank

    Recently, my crankshaft broke(my fault), so I bought one from Kings Motor Bikes. I compared the connecting rods, and while I couldn't get an exact measurement, they seemed close enough. I placed the piston on, but when I turn it by hand, the piston skirt doesn't clear the flywheels! It gets...
  6. M

    Is a balanced single-cylinder crankshaft a myth?

    I know I've asked questions about crankshaft balancing in the past, but now that I've ordered a knew crank for my engine, I plan on actually attempting to make it balanced. I've looked through this forum, and the information on balancing is quite vague. There are no visual instructions or...
  7. M

    Well, I think my motor is RIP'd.

    I'm very angry. I finally got my centrifugal clutch working, and I just rode my bike a few hours ago. I come back to ride it again, and it doesn't start. Instead, I hear a grinding sort of noise, and when I open up the head, I found that the piston only moves maybe 1/8 of the time and only...
  8. M

    Centrifugal clutch bearings problem

    Howdy, motorbikers! After more than six months of absence, I'm trying to get back into motor bicycling. So here's my problem: I got a centrifugal clutch for christmas, and I'd really like to install it because then I don't have to deal with peddling, my problematic bike chain, etc. Well, I...
  9. M

    Gear puller tool stinks!

    Howdy guys! I've been gone for a little over a month, and it's good to be back into the action. I got my centrifugal clutch for christmas, and I'm trying to install it. I took off the flathead screw on the small clutch gear, and for the past 2 hours I've been trying to figure out how to get...
  10. M

    BGF centrifugal clutch

    I want a centrifugal clutch. Particularly one that's a "sprang" type that will let me still use the manual clutch so I can pedal-start the motor. I understand the cent clutch from zoombicycles works like this, but they're out of stock. The one from Pirate Cycles is also out of stock. Seems...
  11. M

    The death of the RAW motor

    I checked back to the site where I purchased my RAW motor. 80cc 66cc 48cc 49cc Bicycle Engine Kits - Motorized Bicycles - Grubee Sky Hawk - Parts - Bike Motor Now it seems they no longer make their motors and now they sell Grubees and Jets. It's really too bad. My RAW 66cc is great...
  12. M

    Decreasing parasitic clutch/drivetrain drag

    My bike is already set on a really low gear, and when I pedal, it seems like it's awfully tough to push the bike when the clutch is disengaged. Are there any tricks for fixing this? I've fiddled with the clutch but it doesn't seem to make much of a difference. Would replacing the spring...
  13. M

    Has anybody tried having the engine drive the gear casette?

    I'm interested in getting my bike to go as fast as possible. I know that this isn't possible for variable street environments, but I'd like to see how fast I can go at a racetrack or something like that where I have room to gain speed. The smallest drive sprocket I could find for the...
  14. M

    Acorn nut stuck on stud

    I have finally decided to switch to long hex nuts, but one of the acorn nuts on my head has decided to stick to the stud, and I can't get it off. I can still pull it out with the whole stud, but if I want to replace it with new long hex nut, I'll need to get off that acorn nut. Any...
  15. M

    SBP expansion chamber... gone!

    Christmas is coming up, and I thought I'd ask for an SBP expansion chamber. I went to the site and... they're gone! Either they're out of stock or they just don't make them anymore! Does anyone have the low-down on an alternative expansion chamber that works just as well?
  16. M

    Crank balancing

    I keep hearing about balancing the crank, but I haven't found any good instructions on how to do this with a china girl. Supposedly it's supposed to reduce vibration and prolong engine life? Can anybody tell me how to do this?
  17. M

    Oil pump injection system

    I don't find mixing the oil and fuel as much of a hassle as some other people, but I like exploring different ideas so I am looking into a separate oil system that automatically mixes the oil into the fuel or squirts it directly into the cylinder. Dan's Motorcycle Two Stroke "AutoLube" Oil...
  18. M

    Am I experiencing pre-ignition?

    This is related to my experimenting with E85 fuel, so this is not related to normal operation on gasoline. As I've mentioned before, I've been running my bike on E85 and over time I've been working out the kinks. I've gotten it to run just as well except for one problem. I think I'm having...
  19. M

    $3 homemade muffler end cap

    As I posted before, my end cap fell off and got crushed by a street sweeper(curse those useless things). I came up with a replacement that works really well and only cost me $3 to make from hardware store parts. All it is is a fender washer with another hole drilled into it(for the...
  20. M

    How can I fix my muffler end cap?

    I took a ride this morning, and after all that time I couldn't get it off, the end cap fell off on its own. I went back to get it, but right as I got about 100 feet away a street sweeper came and ran over it. Didn't suck it up but now it's all bent out of shape. If I can get a piece of...