Parts that should be replaced before installing the kit

Discussion in 'Motorized Bicycle General Discussion' started by Mozenrath, Jun 21, 2011.

  1. Mozenrath

    Mozenrath New Member

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    I thought it would be a good idea to make a thread about components that should be replaced before installing the kit, since as we know the parts that come on the kits and bikes usually aren't of the best quality. This includes both parts from the kit and parts on the bike.

    I installed at 2-stroke on my old(relatively) mountain bike, and here are the parts that I've replaced so far:

    - Mount studs and bolts. I really had to pay the price for not doing this in the first place.

    - Axles. I have no idea why my rear one bent, but it seems like the new one I bought is much stronger. Decent axles don't seem to be very expensive either.

    - Fuel filter. I haven't replaced mine yet, but that's probably the next thing I'll be doing. It's okay but I looked closely at it yesterday and saw some sediment at the bottom that passed through the actual filter part. I immediately cleaned it out.


    I've heard that some people replace their kill switch, but mine seems to work just fine.

    Here's a list I'll be updating from people's posts in this thread:
    EDIT: As a further note, anyone who's considering building a motorized bike should feel free to use their own judgment when considering the advice in this thread. Not all of the replacements are 100% necessary to get a bike working.
     
    #1 Mozenrath, Jun 21, 2011
    Last edited: Jun 27, 2011
  2. DuctTapedGoat

    DuctTapedGoat Active Member

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    Magneto seal (black rubber grommet in the front) needs to be removed and replaced with silicone.

    High quality springed seals (learned this the hard way the other day).
     
  3. DaveC

    DaveC Member

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    My first kit first thing I had to replace was the fuel line, it was brittle and could be snapped apart. I got the fuel line then noticed the filter element wasn't fastened at all and ratteled in the holder so a new filter was bought. I liked the looks of the sick bike parts bolt and stud replacement parts. It was about that time I noticed the holes weren't tapped to the bottom of the holes, I got a new tap set...

    I hated the exhaust pipe from the begining and ordered a SBP expansion chamber right off with the add-on muffler. Soon after that I got a 70cc hi-compression Puch head from treatland.tv.

    I was modding this motor from the start but I'm a hotrodder at heart ;)
     
  4. Al.Fisherman

    Al.Fisherman New Member

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    These are the things that I do, I see that others such as the seals (which I've never had one go bad) mentioned. All these mods or replacements are most likely less then $50.00. Choose what works for you, ignore the rest, but here you have them.

    1. Unpack engine
    2. Check for any missing parts
    3. Remove head
    4. Mill head (flat glass and 230 (or finer) grit sand paper. Rub gasket surface to insure it is flat.
    5. Tap cylinder stud holes to insure they are taped to the bottom.
    6. Discard all studs and nuts.
    7. Replace studs with Metric 8.8 (US Grade 5) Replace nuts with locking nuts. 8mm studs are either 1.0 or 1.25 thread, 6mm studs are 1.0 thread. 8mmX1.0 is not common, but I have 1 engine with them.
    8. Replace spark plug with a NGK or the like.
    9. Replace spark plug wire and boot (check with lawnmower supply) or rob from old lawnmower. Use wire core lead.
    10. Mount the engine properly, no gaps between the bike tubes and engine mounts.
    11. Torque 8mm to 150 to 200 INCH POUNDS
    12. Torque 6mm to 60-70 INCH POUNDS
    13. I install cylinder studs with lock tite, and let set overnight
    14. I coat the head gasket with Copper Kote
    15. May need to bend exhaust pipe for crank or frame clearance. Recommend using heat.
    16. Remove or cap magneto white wire off.
    17. Re solder blue wire on magneto.
    18. Make sure all wires have a good connection and use tape or better yet shrink wrap.
    19. Hook up kill wires AFTER you get engine running.
    20. Try not to drill holes in the bike frame.
    21. Do away with the clutch cable routing; there are a number of options.
    22. On my kit the rag joint had gauge (Metric) 8.8 bolts, If not replace them. I replaced the nuts with lock nuts.
    23. I replaced the chain to a better grade of chain. Bought from Tractor Supply.
    24. I sealed the wires coming from the magneto with RTV.
    Never had a axle bend on me.
     
    #4 Al.Fisherman, Jun 23, 2011
    Last edited: Jun 25, 2011
  5. "the prussian" Shop Dogs

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  6. MotorBicycleRacing

    MotorBicycleRacing Active Member

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    Replacing the rag joint with a sprocket hub adapter is the first upgrade I
    would recommend.

    Fuel lines are junk and a hazard as they degrade fast and could fail
    dumping gas on a hot motor with disastrous results.

    Replace studs, nuts and bolts especially the ones on the chain idler if
    you are using it. Sick Bike Parts makes it easy as they have the parts
    so you don't have to waste time running around finding them.

    Replace the junk Chinese spark plug. I have seen the porcelain crack on them
    which could ruin your motor.

    Replace the intake gasket, make your own and match it to the port.
     
    #6 MotorBicycleRacing, Jun 23, 2011
    Last edited: Jun 23, 2011
  7. Tacomancini

    Tacomancini Member

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    If you have to use the tensioner because of clearance issues then replace the mounting nuts and bolts with grade 8 stuff. I bet the majority of tensioner/spoke collisions are due to the fact that with the stock hardware you can't tighten the bolts enough to secure the tensioner without stripping them. You should be able to kick it without it budging.

    Of course if you can do without a tensioner that is the best setup. Second to that is upgraded tensioners that connect at both the seatstays and chainstays.
     
  8. smemo666

    smemo666 New Member

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    How many studs and nuts do I need to buy and where can I buy them?
    Thanks for yor help.
     
  9. Al.Fisherman

    Al.Fisherman New Member

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    4... 8mm X 1.25 (very few use 1.0) cylinder studs and nuts
    2... 6mm X 1.0 intake studs and nuts
    2... 6mm X 1.0 exhaust studs and nuts
    2... engine mount studs (6mm X 1.0) and nuts (long)
    2... engine mount studs 6mm X 1.0)and nuts (short)
    9... nuts for rag joint bolts (6mm X 1.0)...that is if you already have Metric grade 8,8 bolts. If not bolts also.
     
    #9 Al.Fisherman, Jun 23, 2011
    Last edited: Jun 23, 2011
  10. "the prussian" Shop Dogs

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    That list needs to be a stickey!
     
  11. MotorBicycleRacing

    MotorBicycleRacing Active Member

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  12. Mozenrath

    Mozenrath New Member

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    I was actually going to ask why I should replace the spark plug, but then you edited your post. Thank you for explaining! That'll be another thing I will be looking into.

    The gaskets that came with my kit were okay I guess, except the one that was for the exhaust degraded fairly quickly for whatever reason. So I went to Pep Boys and got a sheet of gasket material for a few bucks. The stuff is very thin, much thinner than the stock gaskets, but the stuff works wonders and just one sheet will go a long way, I'd think. The cereal box cardboard technique I've heard of people using is potentially dangerous and I don't know why people can't just go out and spend a few bucks on quality gasket material. It's even easier if you just lightly coat the area that you want to make a gasket for with graphite or ink and press the material against it and cut out the outline.

    .wee.
     
  13. bikeroz

    bikeroz New Member

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    Replace the single clutch ball bearing that presses onto the clutch bucking bar.
    Found some of the Ch... bearing disintegrates almost instantly.
    Even before use, those bearings are not round, not case hardened enough, or not at all.
     
  14. Diver

    Diver New Member

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    Go ahead and place everything from the kit out on the table or floor, taking notes with a pad and pencil or pen (I perfer black ink- not blue- says "girlie"!)

    Write down everything that came with the kit (engine, tank, carb, CDI, etc..) as you'll need to quickly replace those items with custom aftermarket parts (start googlin') and make sure you order at least two of those parts- at least two! Don't bother mounting the original kit onto your bike, those custom parts are what really matter.

    After mounting your custom aftermarket engine kit, mixing the oil and gas and putting on your helmet- get ready- because now it's time to drive around and vibrate everything off!! Double nut it- lock whatever it- it will come off! You're Motorized bicycle wants to come apart, that's it first and best destiny. Before engine seizure, before bents wheels or sputtering carbs'. This Kit wants to get off your bike no matter what- watch and you'll see!
     
  15. NormO

    NormO New Member

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    The stock air filter should be replaced ASAP. Especially if riding in dusty areas. They stop rocks from getting in but that's about all.
     
  16. Al.Fisherman

    Al.Fisherman New Member

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    I have it in WORD... copy and paste...heck no one reads the "STICKIES" that's apparent from all the duplication of questions asked.

    Not only that..if posting a question, in the title specify the problem, that way when and if someone searches, the title pertaining to the question is listed.

    Hit search and type in Dust Cover, or Bearing Cover, or Coaster Brake....and the title of my post comes up. The search leaves much to be desired...it really isn't that great. That's why noobs find it hard to find what they need.
     
    #16 Al.Fisherman, Jun 24, 2011
    Last edited: Jun 24, 2011
  17. Mozenrath

    Mozenrath New Member

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    Are you just kidding around, or did that actually happen to you?

    I've heard a lot about vibration shaking things off, but that just hasn't happened to me yet. I mounted everything with rubber pads in between and the spring washers that came with the kit, no loctite yet, and nothing has come off yet. I even counted the amount of threads that are through each of the mounting bolts, and there's no indication that anything has loosened. The only thing that got kinda loose was the gas tank, which I tightened and put rubber padding under, and that hasn't been a problem since. I've also been riding my bike every day for about 2 weeks.
     
  18. decoherence

    decoherence New Member

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    i was thinking of making a thread like this.

    i would say don't order a "kit". just get the engine & buy all the other pieces.
    everything that is part of the kit i have either replaced or i am going to replace.

    even the mounts have broke.
    here is a tip.
    i found that a "u-joint repair kit" for a chrysler with some grinding to widen the bolt holes is awesome for the seat mount. it is the "HELP!" brand part # 81006 @ advance auto.

    find a real gas tank.
    get a real throttle.
    get an extra magneto.
    get a real chain from a place like tractor supply.
    not one from a bicycle shop. i have multiple stress fractures from a bicycle chain.
    spend a lot of time mounting the engine
    if the rear drop outs can accept adjustable stays use them. (can't remember what they are called)
    again spend more time to adjust the engine to try & not use an "idler pulley".
    it will take quite a few tries to get both chains to be properly tensioned on both side of the rear tire.
    a chain breaker highly recommended.
    a tool bag to carry on the bike. carry the chain breaker & a few links of extra chain.

    if can afford it, get a shift kit.
     
  19. Al.Fisherman

    Al.Fisherman New Member

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    decoherence...if you broke mounts then the reason is that it wasn't mounted correctly.. The only part I have go bad was a magneto...lasted 3 days. Yea...I got a chain from tractor supply. Forgot about that one.
     
  20. John the Chimp

    John the Chimp New Member

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    Its not a part that needs replacing, but I just made my exhaust port about a quarter inch bigger. By cleaning the cast flashing out of it.
    Ive also learned you need to make sure there are no blemish's in the chrome coating on the cylinder wall.
    The next motor I get will be completly gone thru and polished,piston,rod,wrist pin,bearings,crank. Every moving part will be polished and lubed. Plus quality bearings.
     

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