2 Engines, 1 Bike....2WD...Ludicrous Acceleration

Discussion in 'Performance Mods' started by lowracer, Nov 5, 2011.

  1. lowracer

    lowracer Member

    I gotta give props to 5-7 Heaven for pioneering the 2 engine MB. I've had the urge to build one but didnt have two engines for one bike until another fellow MB& 'er was nice enough to sell me his barely used engine. I just got it hooked up & am awaiting some new bearings for the clutch driver to come via eBay (I messed them up playing with friction drive). Both engines are V-Belt drive.
    One of these big bore high compression Pocket bike engines is more than plenty for a bicycle & just the thought of putting two of these little monsters on a hardtail no suspension bike was bordering on the insane...but what the heck.
    Here's what it looks like so far. Gotta re-install the clutch driver & expansion chamber.

    Attached Files:

  2. 5-7HEAVEN

    5-7HEAVEN Active Member

    This brings back pleasant memories, but funny ones too. My bike and yours look like trick photography/photo shop.

    Like yours, my engines were almost exact duplicates, except the back one had a red engine cover. Pipes were identical too.

    A central auxiliary tank would extend traveling range, but fuel siphoning back to the center tank might be an issue.

    Man, I can hardly wait until you're motoring down the road. Your first ride will be something you'll never forget.:grin5:
  3. lowracer

    lowracer Member

    I gotta wait until the new clutch driver bearings arrive to take this puppy out.
    I hooked up the front engine throttle cable yesterday using some silver/lead flux core solder & a gas grill lighter. I stipped a small piece of extra ceiling fan electrical wire & wrapped a few pieces of the super fine inner wire around the end of a MTB brake cable for the solder to stick to. Heated up the cable & a few touches of the solder is all it takes to make a throttle end. The cable from the brake lever throttle to the carb is only about 7" & works great using a non-V brake lever (less cable pull).
    Will write a short novel once I take this out on its maiden voyage.
    Any suggestions what I should name this one?
  4. 5-7HEAVEN

    5-7HEAVEN Active Member

    How about "Double Trouble"?

    One great thing about twins is that if/when one drive system fails, you can "limp home" @ normal cruising speed.
  5. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    There is already a bike with that name, has the name on the tank....

    Bigboy's "Double Trouble" was a show stopper at the Grange race on Oct 22nd
    along with their other 2 4 stroke bikes.

  6. lowracer

    lowracer Member

    Wont be Double Trouble, but that was a good one...
    I'm still thinking about a suiting name for it. Maybe after a few more rides it will come to me?
    I got the bearings in one of the Staton drivers to cooperate enough (using a hammer & screwdriver) for a good test drive today. Only thing I can say is, "SCARY FAST"!
    When you pull both throttles (2 seperate brake levers, one on each side) the thing shoots forward with violent intensity & reckless abandon. I did play with it some by pulling one then the other to feel & hear the differences. I felt like a kid in a candy store. 5-7 was right about the concert of engine noises you get with dualing engines. I passed a few people in my neighborhood & the looks I got were quite different than the usual 'one engine on a bicycle' look. They kinda had that constipated face trying to figure out where all that 2 stroke rage was eminating from...lol
    I think its a cool contraption, but is it practical? is it legal? is it fun? (No, No, Yes)
    I'll receive the new bearings probably Mon or Tues & will replace them, then ride it around a little more. Here are a few more pics of the finished product.

    Attached Files:

  7. 5-7HEAVEN

    5-7HEAVEN Active Member

    Having twin engines is like having twin kids. Sometimes twice as much to maintain, but a barrel of laughs together.
  8. rawly old

    rawly old Member

    I think they call sumpin like dat a motorcycle. Not much pedaling happenin'
  9. lowracer

    lowracer Member

    I have 3 MB's that dont get much pedal action (don't need to).
    I have 3 pedal only bikes that I use for training & exercise, 2 of them are road bikes & 1 MTB.
    Different strokes for different folks.
  10. rawly old

    rawly old Member

    meant no offense, lowracer, I was referring to motorbicycleracing's
    red side-by-side engine bike. Your bike, on the other hand, reminds
    me of doctor dolittle's push-me-pull-you, 2 headed llama.:jester:
  11. 5-7HEAVEN

    5-7HEAVEN Active Member

    Back in the "learning years", twins were the only way I could think of keeping up with traffic. My previous MB's before twins had me riding on sidewalks and bike paths.
  12. lowracer

    lowracer Member

    I know this seems premature, but I just removed the rear engine from the 'Twins' & am running just the front engine on this frame. It was fun for the short period I ran both, but definitely overkill when using high powered pocket bike engines.
  13. 5-7HEAVEN

    5-7HEAVEN Active Member

    Your choice, my friend.

    Back in the day, not many builders ran pocket bike engines. I still have a 10hp(cough cough) modified pb engine I bought on ebay for cheap. It quit running on its maiden voyage. It coulda been loose studs. Strangely, there is no keyway on the crank, so unsure if timing is off. I also have a stock pb engine I bought years ago; it just needs a pullstart.

    I like pb engines; they are so compact, once you lose the 3:1 gearbox.
  14. lowracer

    lowracer Member

    I'm fond of the 4hp version. I've been getting lots of service from my 1st one & still runs great. The 2nd one is running great too. I may keep the 3rd one for spare parts should I ever blow one up or need a part.
  15. 5-7HEAVEN

    5-7HEAVEN Active Member

    Yeah, pb's are cool. If 460's don't work, I might try twin pb's on Staton's gearbox, center-framed and shift-kitted.:jester:
  16. blue 48

    blue 48 Member

    anyone done a twin ht setup yet?
  17. built_to_go

    built_to_go New Member


    I would love to see some ideas on dual motors on a tandem or any bike really....
  18. max350

    max350 Member

    Should be fun with a video, performance, speed? looks very crazy, but cool. i like it:likelots:
  19. HeadSmess

    HeadSmess Well-Known Member

    well theres your name, pushmipullyu :)

    i like that red one! thats some funny stuff :)
  20. lowracer

    lowracer Member