Need help with cranks and with Carborater

Discussion in '2-Stroke Engines' started by kamikazi_kostka, Dec 29, 2006.

  1. Ok...I switched frames...cause my old would never ever fit...even though it looked kick ass.

    I now have it on a Schwinn High Sierra Mountain Bike, however, I have not found a way for the pedals/crank to clear both the exhaust pipe and the engine.

    I have no way to heat up the exhaust pipe and bend I am screwed, I could spend $40 to see if I can upgrade the inside piece of the crank to 127 mm, but they don't know what is standard. I need like 2 mm more for clearance.

    Another thing, is I got new gaskets for my carb and exhaust as they blew (I had someone install the kit originally for friend's dad...and he messed up). The point is, I mounted the carb horizontally...with the throttle cable coming off to the right side. In most pics I see the throttle cable coming off the top. Does this matter? I want to switch it if it does, but otherwise, I will leave it.

    Lastly, I have a question about idling. I never got my bike to idle ever. After I go 10 mph and pop the clutch, should the engine go, even if I don't give it gas...should it idle without moving with the clutch out? I am just so confused about this.

    Any help would be greatly appreciated. And I will try to take pics to help out...but I don't have a digital camera...i would have to borrow. Thanks


  2. srdavo

    srdavo Active Member

    #1. your carb cable must come out the top.
    the bottom of the carb, the bowl, has a float inside that shuts off the excess fuel, when the bowl is full. otherwise your engine floods. your engine won't run until your carb is sitting as level as possible.

    as for your clearance problems, you can change the pedal cranks to some that are more offset. then you should have plenty of clearence for engine & exhaust.

    gaskets can be made out of high temp material.

    keep us posted on your results.
  3. gone_fishin

    gone_fishin Guest

    good can buy offset crank-arms.

    the carb must be level.

    maybe i should just say "DITTO" :wink:

    welcome to the forums :)
  4. So in terms of the Carb, I need to put it vertically, with the throttle and gas line going into the top, and the circular part on the bottom?

    That is one thing I need to change.

    Secondly, about Off-set cranks..where can you get them? My local bike shop said they might be able to increase the center piece but that is all. They recommended just trying to bend the lever, but I don't want that.

    Thirdly, should I upgrade my clutch lever to the one at thatsdax? That one seems to be of much better quality, and I want quality.

    4thly, I am curious about Sprocket Size. I have gone about 25 mph on my bike, even though it is break-in (eek. Due to my neighbor messing up on the throttle...kept on accelerating even if throttle wasn't twisted). Should I get a better throttle, or is the only included decent? I am just curious as to if the 44 tooth Sprocket will allow 35 mph with my body. 6' and 150 lbs. Also, my bike has trail tires and are 26" diameter. If I can only go about 27 mph on this, I will upgrade to the 36 tooth sprocket, but if I can go 35 mph, without the engine being damaged, I will just leave on the 44 tooth. There are absolutely no hills in my area, so that is not a problem, but there are some roads that are 35 mph that I need to go on to get to friends houses, so I need to go at least 35 mph, as most cars go 40 mph.

    Thanks for all your help, and once I get the kit running, I will ask for help with idling.
  5. srdavo

    srdavo Active Member

    I had to change cranks on my mountain bike for the same reason. I used cranks from a Pacific girls 20 inch 6 speed mt. bike. ($5.00 garage sale+ I have all the other parts for other projects)
    My schwinn mesa had nice offset cranks. So just look around, you can find what you need.
    clutch levers.....I use regular bicycle brake levers. If I need to lock my lever down, I use a heavy rubberband, made from a slice of old bike innertube.
    your idle problem will probably fix itself when you get your carb upright.
    As for going fast.....ya need to go slow for a while, till you find all the stuff that's going to vibrate loose. Then as you get to know your bike, you'll know what parts to keep an eye on. with your 150 lbs. you'll be flying in no time.
  6. gone_fishin

    gone_fishin Guest

    that's not much of a bicycle shop from what i'm hearing.

    i understand the new style clutch lever is more reliable & durable.

    i'm 6'5" @ 200lbs. and have gotten a top speed of 48mph with the 44t sprocket.

    just break the engine in slowly so's the rings and cylinder will seat nicely, giving you the potential for those kick-ass top end speeds. if you're already pushing it, you may be shooting your own foot, so to speak.