Short throttle cable

Discussion in '4-Stroke Engines' started by WU7X, Aug 14, 2008.

  1. WU7X

    WU7X New Member

    Hello all!

    I have a GEBE Robin/Subaru 35 cc bike kit installed on my Cannondale mountain bike. The installation went very well, but now as the engine is breaking in, I have a BIG problem. I have slightly over 200 miles on the engine and it is becoming more and more free-revving as it loosens up. In fact, now when I start it, the engine races at an extremely high RPM. This caused me to snap a brand new belt when I tried to put it into gear!:-x

    When I started to evaluate what was wrong, I noticed that when the throttle is fully closed, the linkage on the top of the engine is ~5/16" away from the adjustment screw. This screw adjusts the idle speed according to p. 14 of the owner's manual. If the cable were a bit longer I think my problem would be solved. As it is, I cannot slow the engine RPMs down enough.

    I have emailed GEBE twice, and just left them a phone message. Hope that they get back to me. If they don't, does anyone have any experience replacing this engine's throttle cable? I checked with a local small engine repair store here and they don't "do" cables.

    I have not ridden my little beauty in three weeks now. In fact, I have lost the majority of the summer due to this and another problem on the bike/engine. This is a bit disheartening!


  2. hi wu is the cable stop at a specific piont on the cable ie not ajustable?
  3. WU7X

    WU7X New Member

    Cable stop

    Yes, the cable stop is at the bitter end of the cable. There is no way to adjust it to make it longer. This short cable keeps the throttle from closing completely. That is why (I assume) the engine is always racing instead of coming to an idle.

    When the engine was new, it was tight enough so that although it probably was running faster than it should have been, it wasn't constantly pulling the centrifical clutch in gear. On second thought, it was intermittantly doing that. I am so inexperienced that I didn't realize at the time it shouldn't be.

    Now as soon as I pull the starting cord, the engine engages the clutch and I have to keep a very firm grip on the front brake or the bike would lurch forward.:shock:

  4. Zev0

    Zev0 Member

    The very first thing I was told when purchasing the GEBE kit was NEVER EVER start the engine without the belt engaged. If you do, you stand a very good chance of doing what you did. Break the belt.
  5. bikejunkie

    bikejunkie New Member

    I have a gebe set up as well and had the same problem at first. I ended finding that one of my tie strips (zip strip) was to tight and was not allowing the cable to slide freely. Also I adjusted the cable at the motor. The best way to attach your cable is to start the motor with the cable loose from the bike. Start attaching the cable from the motor end first and work your way to the handle bars. While you are doing this listen to the motor to see if you start picking up rpm. If you have just the slightest too tight of a turn you will have trouble. I have talked to Gebe a couple of times on my bike and everytime they have been a huge help. I hope all this makes since. Good luck
  6. WU7X

    WU7X New Member

    Funny thing is I have heard that twice now, but never before I bought the kit. don't get me wrong, I would really, really like this kit IF i could only get some miles on it before the snow falls. Sending an engine out with a short throttle cable is not something I had control of. Nor is the fact that it seems impossible to get a reply from the company.

    The engine itself is a wonder. The wheel ring excellent. I spent a lot of money having a new wheel wired up with 12 ga. stainless steel spokes to handle it. I put it on a 15 year old aluminum alloy mountain bike frame because I wanted something that could handle the output and get me safely down the road. The bike was professionally rebuilt from the ground up btw, all new bearings, chain, frontend, etc. I am not installing another belt until I have the throttle linkage issue cleared up.

    I see that you are a member of the Royal Order of the Golden Eagle. Perhaps you can tell me if there is a secret hand shake or something I need to do to get help. I have talked with Julia a couple of times and she is a sweetheart. In fact, I ordered the kit from her and was never told about the clutch in gear issue. Now when I call I hear a recorded message. Not good customer service.

    I wish GEBE the best of luck in the future. All I want is a new throttle linkage assembly that I can cut to the proper length and fit myself or have a local professional help me with.
  7. fetor56

    fetor56 Guest

    Dunno about your throttle setup man but this is what i did with my Titan:
    Make-up a new's not hard & since the throttle cable is under very little pressure(comparatively speaking) u can use normal solder on the nipple at the end.
  8. WU7X

    WU7X New Member

    Will try the zip tie fix.

    Bike Junkie,

    Thank you for the great idea. I will give it a try. I don't know if it will work though as I can easily move my throttle cable back and forth now, and with the throttle trigger as far back as it will go is when I measure the 5/16" shortfall in length.

    Will let you know what I find out this weekend. I have relatives coming over for the next couple of days.

  9. WU7X

    WU7X New Member

    My idea exactly


    You and I are thinking exactly alike. That is what I think needs to be done. All I'm asking for is the parts to do it. I enjoy tinkering on my cars, truck, and now this motored bike. One lesson I learned long ago was that the best way to do a job was to have the right parts. That's all I am trying to ask for.

    Thanks for your comments. Will let you know how things progress.

  10. throttle fix

    Hi guys, I usually do Whizzers, but I had 2 GEGE's in my shop. I put rotary throttles on them, with new cables to fit that handle.
    I for one, do not like "trigger" throttles.

    Too much like a weed-eater, and too little like a motorbike for me I guess.

  11. WU7X

    WU7X New Member

    Where do I get one.


    I like your idea! Where can I get one? Does it fit on regular bike handlebars? The guy that rebuilt my mountain bike installed a bar with "Club Roost Go Fast" written on it. The brakes and shifters are Shimano XTRs from the mid-90's. I'm guessing that the brakes and shifters would not present a problem. Just concerned about the rotary throttle working with the bars?

    I am eager to purchase a rotary throttle like the one you described. Please let me know where I can get one.:grin:


  12. rotary throttle

    HI I should have them in stock, they fit 7/8 bars (std bicycle) I may have a couple different models.

    The worst you'd have to do would be to shorten the end for the carb to adjust it's endpaly. For this, you can use a HT clutch cable brass stop (I have those also)

  13. WU7X

    WU7X New Member

    Problem solved!

    Mea Culpa!

    I received an email from Julia at GEBE. She attached a link to a page on their FAQ webpages that discussed this problem pretty thoroughly. As several of you suggested to me on this forum, I cut all the zip ties that held my throttle linkage and the kill button to the bike frame.

    This is where I start getting red in the face. Once I had done that I was able to fully close the throttle linkage! so although the linkage had always moved easily it still was bent too much. That "pulled" it open.

    Once I figured that out, I reattached the cable to the frame, very carefully. I also removed the GEBE spring clip that is supposed to hold the trigger to the bikeframe. It just didn't work properly. I then zip tied the trigger to the handlebars.

    Now all is well. Yes, I have bitten my tongue metaphorically about all this.

    Thanks to all who have helped me solve this problem. I still think I will look into a twist grip type throttle though. It is a much more "natural" approach to accelerating and decelerating.

    Dale WU7X:cool: