Standard upgrades for Motorized Bicycles?

Discussion in 'Motorized Bicycle General Discussion' started by Fogcity123, Jul 27, 2013.

  1. Fogcity123

    Fogcity123 New Member

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    Hi.
    With Harley's it was always changing the air filter, pipes and rejecting the carb - most bang for fur the buck and the first thing most people would do. Is there a short list for these China 2 strokes?
    Thanks.
     
  2. mapbike

    mapbike Active Member

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    Re: Standard upgrades?

    Spark plug NGK B5 6 or 7 HS (B6HS) is the good medium range plug, better NGK plug boot, stock ones are junk normally dont last very long and then they fall apart at a bad time usually, a better exhaust is always top of my list and I pull head and jug and upgrade the wrist pin bearing, i've had two major failures and both were due to cheap junk bearings, after 150 or so miles I start the carb tuning process after I install the exhaust and air filter I plan to run and have settled on the brand of oil and the ratio I plan to run.

    These few upgrade will make a big difference in performance and reliability in my experience, if you can I would do three things before ever mounting the engine and running it, get the better spark plug get the NGK or another good plug boot replace cheap wrist pin bearing with better one these three things will only cost you about $20 or maybe a little lessbut will help the reliability of the engine while its breaking in, then I'd go to a better flowing exhaust and tune the carb to lean the mixtire down some because these engine are known to run fairly rich out of the box and 4 stroke a lot.

    Im sure you'll get other opinions here and thats fine but I know from experience the things I listed are worth doing right from the get go and many others here do at least some of the same when they get a new engine.
     
  3. wheelbender6

    wheelbender6 Active Member

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    Re: Standard upgrades?

    In the 1960s, you hopped up you muscle car with the three H's; Holley, High rise and Headers. (Carb, intake, exhaust). Except for the advent of the ECU chip, I don't think much has changed.
     
  4. mapbike

    mapbike Active Member

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    Re: Standard upgrades?

    And if you were running a small block chevy a set of the double humped or as some called camel humped heads were always a nice addition since they had the 64cc combustion chambers, I still have two sets of them one set were from a vette and have the accessory bolt holes for all the brackets. I wasn't doing it in the 60's. Because thats when I was born but I was raised up loving and working on the 60's muscle cars and building my for 327 when I was 15, dang those were the days.....!

    But yes. You're pretty much right, I get a good flow on the exhaust, tune the carb well and those two things alone make a world of difference in how these little engines run.

    Map
     
  5. Inky

    Inky New Member

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    Re: Standard upgrades?

    These guys are right on the money for standard performance mods. as far as some small technical stuff that I would personally recommend to solve a problem before you have it;

    -replace the ragjoint sprocket assembly with a manic or similar hub adapter. the ragjoint can ruin your wheel in my experience. others have had good luck though. an HD wheel will hold up just fine.

    -grease all your cables (throttle, clutch, even brakes) they can fray inside the housing over time if you dont and the last thing you want is any one of those cables breaking mid ride.

    -install an inline fuel filter and replace stock petcock. the stock pet is pathetic, and the filter inside it is a joke. the filter can clog and the petcock can leak.

    -people swear by loctite, ive never used it. just make sure your bolts are tight every other ride or so.

    theres a million and one other things to do to these engines, it all depends on what you want out of it. ive built little put puts for friends that ran about $300 when all was said and done, and ive built two bikes that would have ran over $2000 if i bought everything off the shelf. which leads me to my biggest tip;

    Bargain hunt!
    as far as bike parts go, thrift shops and ebay/craigslist are your friends

    as for engine parts, if you cant find it cheap on ebay or craigs search different vendor sites. theyre all competitive and the prices change so you can usually find one thats got a good deal on whatever your looking for.

    Good luck and happy riding!

    Inky
     
  6. chainmaker

    chainmaker New Member

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  7. CTripps

    CTripps Active Member

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    The minimum?
    Replace (upgrade)
    • plug, plug wire and boot
    • fuel line and filter

    That should cost less than $20 depending on where you go for parts.
     
  8. dodge dude94

    dodge dude94 New Member

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    I agree with the others: good plug and wire as the minimum.

    If you wanna do some slight upgrades before you drop it into the bike, pull the head and jug off, and lap them.
    Get you some 400grit wet/dry sand paper, tape/glue it to a sheet of glass, wet it and start sanding in figure 8 motions. That will make a slight (slight, as in not noticeable) compression bump but more importantly make sure the gasket mating surface is flat. If you have a dremel and some small files, you can lightly "polish" the exhaust port so that it's not as rough as it is stock. But you don't wanna sand it down too far as you risk changing the port timing and fubar'ing your engine. After that, port match your exhaust gasket to the engine and you might also open up the factory exhaust flange on the muffler a bit. And you might also ditch the factory acorn nuts on the head if you feel uneasy about them.

    As for any other upgrades, wait until the engine is broken in and you're running a normal gas/oil mixture before you start cranking the power and what not. :)
     
  9. Risingsunn

    Risingsunn New Member

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    A few things that come to mind:

    Sick Bike Parts makes a good exhaust that almost everyone agrees on.
    Of course a new spark plug
    I would even say replace the spark plug wire with something like Magnacore.
    A bigger sprocket if you don't mind losing a some low end power for high end speed.
    Possibly a new carb though there is some debate about the benefit.

    For some "not so performance" related upgrades:

    Better grade mounting hardware
    Better grade chain
    Disk brakes for more reliable stopping power
    Lower gauge spokes for the rear if you intend on using the rag joint.
    Possibly repacking all bike bearings since you will be putting a lot more wear and tear then was intended.

    Just a few things off the top of my head.
     
  10. Master-shake

    Master-shake New Member

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    should I be installing new upper wrist pin bearings as a mandatory thing? Where can I find a really nice upgraded one? will simply oiling the stock one not be sufficient for dependability?
     
  11. fonzie

    fonzie Member

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    Bearings direct carry them and while your at it, get a K-10x14x15 bearing. Stock is k-10x14x13. The k-10x14x15 is 2 mm wider.
     
  12. Master-shake

    Master-shake New Member

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  13. fonzie

    fonzie Member

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    Yep, that's it
     
  14. mapbike

    mapbike Active Member

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    Thats a good one to use, I have gotten some from motion industries and have run them with no issues, but the one from bearingsdirect.com are wider at 15mm and to up the room between the con rod and piston better, just remember if you change it out just oil it good with a bit of 2 smoker oil when you install it and then it wont start off dry the first couple of seconds the engine fires off.

    Here is another place that offers some nice upgrades, nice gaskets and a few other things like a upper wrist pin bushing for those who would rather have it over a bearing.

    http://juicemotoparts.com/?limit=15

    Map
    reddd
     

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