My highly detailed plan, does it hold water?

Discussion in '4-Stroke Engines' started by Benz, Apr 27, 2011.

  1. Benz

    Benz New Member

    Well here goes... My basic plan is to mount a Honda GX120 replica
    $%28KGrHqN,!l0E1F2GWImuBNbSKLW4s!~~0_12.JPG to this bicycle frame 129-3323227SPA74UC898983X.jpg The detailed plan for mounting will be determined later when I receive both the motor and the bike, i will have to create or buy a mounting plate which the engine can sit on, hopefully looking something like this draw1.png then engines shaft will then have a between 10 and 20 tooth sprocket attached(unsure which will give best performance for the engine and terrain) which will connect to the gear on the pedal by connecting a separate chain, then I will use the existing chain attached to the pedals to connect to the rear wheel which will allow me to change gears without paying for a shift kit that will cost as much as the motor itself (although this will mean the pedals will spin when the engine is running)and encase my wording has confused you, here is another "helpful" diagram draw2.png once I have completed this, given that I haven't acquired 3rd degree burns in a huge explosion I will modify the front brake cable so it controls the throttle.

    Assuming everything works I will look into the following

    - repositioning the petrol tank
    - adding a kill switch
    - quietening the engine
    - tuning the engine for the highest efficiency at 40mph
    - adding rear view mirrors, front rear and signalling lights and a speedometer
    - modifications such as a stereo or recumbent seat to make long journeys more fun

    Feedback is appreciated as I have little background knowledge in the feild of mechanics.
    Last edited by a moderator: Dec 18, 2015

  2. ocscully

    ocscully Member

    The first problem I think you are going to run into is the motor will not fit into the frame shown. You will have a better chance of fitting the motor in a Cruiser style frame. The second area you need to address is getting the right amount of reduction. This type of arrangement might help in getting the right amount of reduction. They also have a mounting plate that works for these clone motors. In fact this company has quite a few products that might help with your project.

  3. machiasmort

    machiasmort Active Member

    If I had it to do all over and was starting from scratch w/o a kit, I'd mount the motor above the rear wheel. Just my opinion that I think it would be an easier build and allow for more transmision/ gearing options.
  4. spad4me

    spad4me Member

    How much does that motor weigh.

    As the previous posts say the reduction you are proposing is not enough..
    I use a 6 pound six hp engine with 5 to1 transmission setup with a ten tooth output feeding a (48 to 56) crank freewheel attached to a (24 to 30) sprocket driving the seven speed freewheel attached to the real wheel.
    My reduction in first gear is 34 to 1

    This reduction varies until the hp is too small to move me any faster usually 16 to 1
    Last edited: Apr 27, 2011
  5. Benz

    Benz New Member

    The engine in the picture is 25 pounds and only 4 horsepower, which engine are you using?

    At the moment it looks like i need to rethink my engine choice, any recommendations? and remember I live in the UK, most vendors that i have been linked to dont ship to the UK or charge $100 or more for shipping (not to mention overseas warranties are a nightmare)
  6. spad4me

    spad4me Member

    I use a gp 460 two stroke it has the most bang for your buck. Daves Discount motors sells them for around $255.00.

    This tuned exhaust is the one Daves recommends. I do not use this one.

    You will need stronger clutch springs here are some from Staton made for the gp460.

    This motor with a thats dax pipe will supply around 6 horsepower. If you port it with a pipe around eight horsepower..

    Also Thats Dax has just started carrying a similar engine for around $200.00 shipped.
    Gt50r 4.2 hp engine

    Both engines need a tuned pipe to make more horsepower.
    I like the one from sick bike parts It sells for around $70.00.

    I use a similar setup to the following post The parts are listed in post number 140. Read the whole thread to get an idea of this setup .
    Sadly,The scooterguy went out of business .
    Detonator TuningSolution used a similar setup to commute DAILY at speeds avereging 40 mph.
    I use a 26 inch full suspension steel frame mountain bike

    I use a home made 18 inch steel plate with a hole cutout for the transmission snout anf 5 holes drilled for the engine transmission mount scheme the steel plate is the size to span the top tube to the lower tube.
    Thats daz sells a plate for around $24 00. I prefer to make my own.

    Check out this monster that Daves Discount Motors just started to sell
    A Skopod 60, Sadly no tuned pipe yet.

    I have no camera I spend my cash on other things. Sorry no pictures.\
    Do browse the forum for more Ideas.
    The cheapest setup is Friction drive.
    Friction drive is ok if you live in a DRY FLAT place. If not YOU will NOT like it.

    Here is another engine place try to stay with a 4 stroke honda 50 as the biggest engine." Keyed Shaft, Overhead valve LOS 7000 RPM
    I do not use a honda 50 check this site for more information.

    I like this one
    Last edited: Apr 28, 2011
  7. Benz

    Benz New Member

    Those suggestions would be perfect IF I lived in the USA, however I live in the UK where parts like this are simply unnavailable next to none, the engine im currently looking at costs the equivilent of $140 with shipping, whereas the suggested ones would be in the region of $500 with shipping and tax added

    The thing I need figuring out is how to attach a sprocket to a "Q" shaft, or find a sprocket with a q shaft if they exist...
  8. spad4me

    spad4me Member

  9. Benz

    Benz New Member

    theres 2 kits available that are actually IN the uk, 1 chinese import from a uk seller and some skyhawks which cost £200, no 4 stroke kits, however im leaning more towards the skyhawk option as i dont really like the idea of straddling the bike like a horse...
    Last edited by a moderator: Dec 18, 2015
  10. philcrudo

    philcrudo New Member

    Something like this

    Attached Files:

  11. philcrudo

    philcrudo New Member

    Like this?

    Attached Files:

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