Noob w/ Engine curiosities and Mfr Rundowns....

Discussion in 'General Questions' started by BillMckraken, Jun 4, 2011.

  1. BillMckraken

    BillMckraken New Member

    I've been researching and reading up on these motorbikes for a lil' bit now, hoping to make correct decisions. I've read quite a bit on the forums and continue to read more (great site!). I have a few questions that I don't believe have been asked. Also I have a couple I couldn't find good answers for. All the questions are focused on the engine.
    For all the engine questions; I would like to assume a chain / belt drive with any of the possible "rigid drive" styles (Nuvinci, SPB shift, HD axle, etc). E.G., no friction or trailer drives and preferably V mount (though not required if it satisfies drive system). Sorry for the build-up, just trying to help eliminate variables.
    First, has anyone tried or would it be possible to use an R/C type engine for one of these bikes? Been a while but I know Zenoah makes some 30-60cc airplane, heli, and used to make 1/4 scale car engines. R/c engines in this size are around 400 and up, so this would only be viable as "longer lasting" or it's not worth it. I DO know that the Airplane and Heli engines probably will NOT work as they are designed for large air cooling mass and a (more or less) steady RPM. Was curious if anyone has walked down this trail yet.

    Second, is there a way to run the Mitsubishi or Tanaka engine's in the assumed drive system? For instance, has anyone V-mounted one of these with an SPB shift kit? From what I can tell all these are used in friction or trailer and seem to be a weedeater style engine. I guess these have a small squared output shaft or something then? Is there a marketed Gear box or kit to get these in V-mount? These engines are a bit more so, here again, would these last long enough to warrant that cost?

    Third, could someone please list all engine models that will currently fit my assumption above (drive, mount)? Here I'm curious about different models. From what I can tell ALL the current V-mount kits are using 2 engines (48 or 66) regardless of brand or store. If this is correct, a Jett or Grubee or silver flying horse, etc; are all the same. So all these that are the same (interchangeable) could be just identified by the most popular one, I suppose. I'm still new and looking, but from what I can find; it seems there's only one style that fits my assumption!?!? A Grubee style china engine. Oh, I believe Kings Motors sells a Grubee style upgraded with a cylinder or something so that WOULD be different. What are all the others, if any?

    I apologize for the windy post and many questions. I guess the greatest point of the entire post is to get a list of all possible engines (being different) that can fit the assumed mounting drive style.

    Thanks to all that take the time to read and offer a response.

  2. motorpsycho

    motorpsycho Active Member

    the r/c type engine queston has been asked before.
    a nitro r/c car engine would not give you enough torque.
    high rpms yes, low torque to move the weight load? no.
    the r/c car engine fuel (nitro) is expensive...$12.00 - $15.00 for a quart, $40.00 for a gallon.
    you would have to figure out a gear ratio and find a gear bigger than the one on an r/c car engine because those gears are made to mesh with a spur gear, not pull a chain.
    you would have to figure out a clutch set up because the r/c engine use a centrifugal clutch that is very sensitive because the cars are so light weight. (an airplane engine does not use a clutch, they are direct drive to the prop).
    i'm not saying that it wouldn't work, i'm just saying that it would be expensive to build, and expensive to run. it would be much easier and cheaper to just get a cheap chinese 2 stroke (66 or 48) because you will end up with everything you need to run it and you would not have to have parts custom made...and the fuel to run it is a lot cheaper.
    now you could do something with an electric r/c helicopter motor because it has been done. an electric r/c motor will give you a lot more torque than a nitro r/c engine. a friend of a friend built one and his bike will literally spin the rear tire at will, and the bike tops out around 60 mph. BUT, he has about a year invested in building it and machining all of the custom parts in his shop. he's running lipo batteries and is using an r/c helicopter speed controller for the throttle. the bike was sold for $10,000.00.
    here's a video of it in action.

    yes all availble chinese 2 strokes engines are either 48 c.c.'s or 66 c.c.'s there is no such thing as an 80 c.c. chinese 2 stroke, even tho some are advertized that way. externally the 66 and 48 are the same, internally the piston and cylinder bore on the 66 is bigger than on the 48. i think they use the same stroke, but i'm not positive.
    in reality if someone gave you a 48 c.c. and a 66 c.c. side by side on identical bikes, you wouldn't be able to tell the difference between the 2 engines even if you rode the bikes. a 48 c.c. will give you just as much power and speed as the 66 c.c. but the 66 will have a tiny bit more low end torque. my 48 c.c. will outrun my frineds 66 c.c. and both bikes are the same style. i have an expasion chamber and a 41 tooth rear sprocket while he has the stock exhaust and a 44 tooth rear sprocket.
    at one time when we first built these 2 bikes they were identical (stock everything, and both had 44 tooth rear sprockets.) my 48 was still faster on the top end than his 66. yes, we weight about the same, and even if we switch bikes, my bike will still beat his. but now since i added the expasion chamber and the 41 tooth sprocket, my 48 will walk away from his 66.
    seriously, you will get the same exact same engine from an e-bay vendor for $150.00 that you would get from an on line vendor for $250.00.
    Last edited: Jun 4, 2011
  3. BillMckraken

    BillMckraken New Member

    Thank you for your response and video! I was pretty sure all the imported engines were the same. I'm also thinking the 48cc might be the better way to go (a Grubay, lol). I've read enough people, including yours now, who don't seem to show much more power in the 66cc (stock). Throw in the terrible balancing in the 66cc and blowing top conn. bearings; definitely leaning 48cc in 2-stroke.

    On the R/C engine/ motors I believe you missed my intent a bit; I apologize for not being more specific. I knew people were working on brushless DC bikes n' things, but hadn't seen one working (thanks again there!). Those motors do have a lot of torque and rpm. Myself (in the scale world) I'm old school and prefer Brushed DC. I'm not looking to do an electric bike I guess, battery technology just isn't there yet.
    On the Engine side I wasn't referring to the "glow" style R/C's that run on nitro. Their Bhp is only developed at high rpm (20-30K) and would be a gearing nightmare as you mentioned. When you get into the 1/4 scales in any category Heli, Airplane or car; they all get into gasoline burning, spark ignition, 2 and 4-stroke engines.
    These larger engines are the ones' I was asking about. Several are CNC machined from ground up, larger cooling area on heads, more precise carbs. in some cases and even electronic ignition. Heck you can get into 2 cylinders as well! I'm pretty sure one of these would work VERY well (excluding budget of course). here's a couple links to show examples.

    First link there Gasoline 50cc 2-stroke w/ reeds and electronic ignition. 5.5hp 1,500-8,500 working rpm.

    Fuji's are nice engines. Gasoline 64cc Fully CNC. Full bearings (Including conn rods) Electronic ignition. Chromed internal crankcase!!! 5.7hp 1,500-9,000 working rpm.

    Heck Even O.S. makes one. This is your standard "low end" in the R/C world. 55cc Gasoline Still good bearings and electronic ignition. Cast head though. Has the look of the Heli engines that size, less cooling.

    The last one is a bit big, but just wanted to show there's 2 cylinder's out there as well. ;).

    There are many brands and styles. I'm surprised actually that this hasn't been done yet.

    For me I'm going to be looking towards being simple as it's my first bike. I guess the choice of brand in these 48cc 2-stroke is easier now, knowing they are the same.

    I did also find, from reading more on the site; what all was needed to get a 4-stroke into the V-mount. That makes more engine options available to think about.

    thank you again for your post.
    P.S.- I'm in Indiana as well ;)
  4. dougsr.874

    dougsr.874 Active Member

    Whatever you decide stay away from Kings Bikes....they are crooks and will not answer the phone nor emal after you buy.....also the chain on the Skyhawk engines are regular bike chains and will break immediately....also the CNS carbs are no good....
  5. motorpsycho

    motorpsycho Active Member

    yeah i understand which r/c engines you're talking about now that you say 1/4 scale.
    I was thinking that you were referring to the 1:10 scale nitro engines.
    I'm into r/c too and i have had a couple of 1:10 nitro r/c's (a monster truck and a dragster).
    I prefer electric because nitro is so expensive, and you have to constantly fiddle with the nitro engines.
    right now i have four 1:10 scale r/c's (an old tamiya Superblackfoot that i restored, a duratraxx evader that i converted into a grave digger monster truck, a custom built 4wheel drive, 4 wheel steering monster truck, and a tamiya re-issued sand scorcher v.w. baja beetle).
    back to the engines...
    I bought all of my engines from boygofast on e-bay. i had great service (through e-mails), super fast shipping, and all 4 of the motors run great and all of the parts were in excellent shape when they came to me. 2 of these engines are mine and the 2 other ones went to friends of mine.
    yes, the 66 c.c.'s tend to vibrate, while the 48 c.c.'s don't.
    my 66 vibrates pretty bad at w.o.t., but my 48 is as smooth as silk.
    all of these kits came with the bigger chain (i think it's 415 chain...motorcycle size).
    yes, i have also heard that the cns carbs are junk (the newest versions that come with some of these kits). I've had very good luck with the good old n.t. carbs that came with the kits before the cns carbs started coming with them. I'm not sure if you can still get an engine with the old style cns carbs or not. but i am pretty sure that you can still buy replacement n.t. carbs off e-bay for like $12.00. so even if you do end up with a cns, and it gives you trouble, you can just order an older style n.t. and it will bolt right on.
    but, be prepared to tune the carb and possibly re-jet it. I had to re-jet all 4 of the carbs for the engines i got, but it was real easy to do. the hard part is figuring out what jet the carb needs.
    it takes a lot of trial and error switching jet sizes until you get it to run how you want. my 48 c.c. is an oddball style if 2 stroke, and i don;t think they even make it anymore. It has a different style n.t. carb than the more common ones found on the 66 c.c. engines. The carb on my 48 is mounted directly to the cylinder and there is no intake tube. jetting this carb was a bit of a pain because it's pretty difficult to get the carb off because of the way it's mounted. it's mounted with studs, that have nuts on the ends to hold the carb on, but the nuts sit in recesses in the carb, so there's no way to get a wrench on the nuts. I had to drill out the stud inside the nuts until the nuts fell off. then i replaced the studs with allen head bolts so the carb is much easier to get off now if i ever have to remove it. the bonus to having this style engine is clearance. as you will see. i have this mounted in a 20" schwinn stingray frame, and clearance is a big issue. but with the carb mounted like it is, the engine fits right into the frame. if it had the intake tube like most engines do now, it wouldn;t fit. I probably would have had to cut the intake tube way down to get the seat tube clearance that i have now.
    here's what my 48 c.c. looks like.
    before anyone mentions that i'm not running a fuel filter, it;s because i have not found one that will fit yet. i need a TINY filter so that the fuel line doesn't kink.

    yeah a 4 stoke would be cool, but i just don't like the way they look when mounted in the frame to be honest. they look like someone slapped a lawnmower engine into a bike frame.
    with the 2 strokes, they look more "motorcycle" and they seem to fit the look of being in a bike frame in my opinion.
    Last edited: Jun 4, 2011
  6. 5-7HEAVEN

    5-7HEAVEN Guest

    The most popular r/c engine is the 4.2 hp GP460 engine. It has the correct 76mm clutch and four-bolt motor mount to utilize standard bike engine drive kits.

    I have used this engine in friction drive and frame-mount Scooterguy drive system/shift kit.

    I am presently using a 2.8 hp Tanaka 47R engine with pipe. This is also frame-mounted ala Scooterguy/shift kit.

    Front frame-mounted, but not centered in the bike frame.

    SBP uses bicycle sprockets; Scooterguy drive uses 8mm(T8F) pocket bike chainring, 5:1 pocket bike gearbox and 8mm engine sprocket.
  7. BillMckraken

    BillMckraken New Member

    @ motorpsycho Nice to see you with the old school electrics from Tamiya's hayday. Ty for the pic of the bike too ;). Also I totally agree on the mower look of the 4-strokes. For me n' R/C I only have a Kyosho Mini Inferno 1/16 scale carbon fiber. I was into the R/C's big round the mid 90's, heh used to work for a local hobby race place.

    @ 5-7Heaven good info there! That engine you mentioned is for the 1/5 HPI Baja R/C. I'm not sure who the mfg. of that one is, though I'd bet Taiwan or Japan. What did you think of the reliability of that GP460 with bikes?

    Thanks again for the responses!
  8. Pepsi Challenge

    So....u got Friction drive, Center Mount, and Rear Mount drive systems.

    All will have trolls that argue either way.

    If you go with the RC engine type, there are two different size clutches....if engine cc is less than 33cc the clutch is usually 52 or 54mm. Over 33cc and the clutch size is 78 or 77mm.

    You got Chinese Engines vs Japanese brainer for me anyway.

    Again. Trolls.

    You got Belt vs Chain drive


    You got cheap or expensive


    2 stroke vs 4 stroke

    Fools and Trolls

    You have jackshafts, belt drives and primitive trannys (No, those are not caveman crossdressers..dirty minds you have...)

    Whichever way you go sir, the motor you finally unpack is like a box of chocolates.....literally, you never know what you r gonna get... if you bought a chinese engine increase your risk factor by 2 or 3.

    All these guys INCLUDING myself can tell you whats up, but at the end of the day, you dont know what you got until you got it.


    Bottom line, this is going to be a depreciating asset or a middle class investment....(don't worry guys I include myself in this classification) , just saying the truth, so no matter which way you go, you are spending money, on a belt, on a chain, on high performance gear, on a new chinese engine cuz they suck, on new tires, brakes, blah blah.... oh yea, and if you do go b@lls deep and try to sell your bike, you will get a fraction of what you paid into it.....

    It is not like buying gold or silver or other obsessions you could choose to have....that is fur sure.

    Motored bikes is a novelty and a hobby so understand, this isn't like a new motorcycle where you pay and just drive forever....things break down fairly constantly....if it doesn't break down, YOU break it down and do preventative care.....ect.

    Look to spend from $150 to $700 before you are good to go.

    In summary:

    Dunno about YOU, but I will take the pepsi challenge with anything you are considering buying against my GEBE rear drive with a 41.5cc Zenoah G-43L engine bolted on. It pushes 45mph without the hipo carb i just bought and I am 6' 2" 230lbs.----yes I am trying to become part of the 50mph club.

    Is it excessive?....YES!!....but I have the option of being able to haul a$$...and I like options.

    Hope this helps.
    Last edited: Jun 12, 2011
  9. motorpsycho

    motorpsycho Active Member

    "Motored bikes is a novelty and a hobby so understand, this isn't like a new motorcycle where you pay and just drive forever....things break down fairly constantly....if it doesn't break down, YOU break it down and do preventative care.....ect."

    this is by far one of the best quotes that i have read to date.
  10. Happy Valley

    Happy Valley Active Member

    On the Japanese made utility engines, I know of no kit currently available commercially that accomplishes what you're asking. It can and has been done, and done well, but requires some skill at fabricating a one-off design.
    Most of the engines in this class and certainly the ones you mention, utilize and come with a centrifugal clutch at the output, 78mm in diameter in the 30cc and up displacement.

    That's a straight forward approach and contains some no-nonsense advice but it's a little harsh to characterize members as trolls who offer honest opinion and advice, as much as it would be to label your post as such.

    People recommend what they own, true of many products and no one wants to feel they made a bad decision. The discerning reader knows that, and with a bit of study decides what is best for them.

    As one of the resident sages on this site once reminded me:
    "Everything in life is a trade off, the trick is getting what's right for you at any particular time and place."