Hello from Salem Oregon

Discussion in 'Introduce Yourself' started by Orpackrat, Oct 8, 2010.

  1. Orpackrat

    Orpackrat New Member

    Hello all, I just moved to Salem in Oregon not too long ago.

    I have a mountain bike that I've put one of those cheap motor kits on (you know the ones from eBay). I used it for a long time since I had a truck that got only 10 MPG. The motor stopped running about the same time I ended up getting a cheap fuel efficient car so I left the bike parked. Now that the engine blew up in the car, I'm going to go back to my bike. Only problem is, its not running, I think I know the problem though.

    Anyways, I've done some different things with motors in the past, some somewhat successful, some not, and some I used until they broke.

    My very first attempt with an engine on a bike was rigging a chain assembly to my brand new Stihl 290 when I was about 14. Before I could get too far into it, my parents stopped me as it was a nice saw and they wanted me to be safe and keep it a single purpose motor.

    For a few years, that was the end of motors on the bike, I had a car, an old snowmobile, if I wanted to go somewhere, I drove.

    (All that I built, besides getting the motor and a bike frame mentioned below, they were all built with stuff I already had laying around)

    I ended up moving to the coast about 5 years ago from central Oregon and my first attempt with a motor (chainsaw). I bought a cheap gas scooter with a 33cc engine, it needed a new chain and was one of those cheap folding ones that are famous for the steering breaking off and bad accidents, it also had not working brakes. I got it running and took it easy riding in on the flats just because (not the safest). No brakes and bad handle bars led me to quickly change the motor options. I cut off the back end of the scooter, took an old bike rack (kind that mounts to the seat), reinforced the bolts, welded a drop down and attached the back half of the engine assembly to my mountain bike. It worked alight, the seat pole hinge would allow me to make corners but I found that since there was not much weight on the powered wheel, it would loose traction a lot, especially up hills.

    The next mod to fix it was to use some scrap steel, make some bars that fixed the seat rack over the tire. I then used the shock from the scooter to apply force on the rear wheel for better traction. Now it worked perfectly except for 1 small problem: the bike could not turn. I had 3 wheels in contact with pressure and it would not turn more that about a degree or 2 with me on it. That build had little life.

    The next mod and the best one, I bought a old mountain bike for $5 at the junk yard, stripped it down to just the frame, with front end. Then I welded the scooter rear end to the back of the bike. Had a kind of hybrid, half bike (front end with brakes) and half motor scooter. Didn't have the pedaling ability but it was gas and go, I rode it till the scooter frame cracked from the stress. Rewelded the scooter frame and rode it till the tire blew, chain broke, carb broke, and engine finally went.

    For awhile, I didn't do anything else. I ended up with a truck that got 10 MPG for when I needed it most but I ended up going back to my bike. Figured I'd actually buy something this time, lack of money lead me to buy something cheap so I got one of those cheap ebay 2 stroke kits. Worked alright, it was not really made for my kind of bike (frame too big for lower motor mount and fuel tank). I got it working anyways. Did a lot of riding on it, then the exhaust broke. Since I had my welder at my parents for some work I did for them, I did the dumb thing of taking the exhaust apart. It did not go back together right after that. I managed a temp fix with some aluminum tubing but the heat dissolved shortly after. I tried some JB weld, work great until I read the label and found it was not rated for a high enough temp. It dissolved as well. Got my welded back and went to see if I could put the exhaust back together, it worked somewhat but eventually started leaking and broke free again. The motor is currently not running, and I am looking to fix it and start using it again to commute to work (14 miles 1 way).
    I believe I just need to order a new exhaust system to get to right back pressure for the motor to run. Currently, the motor will not start, I might get lucky with some starter fluid in the cylinder and the throttle at full but its a spurt and will not stay running. If the engine is hot, It sometimes starts at full throttle and if you don't keep it at full throttle, it dies. Its getting spark, fuel, compression, just not running. I can unscrew the spark plug, set it on top the cylinder and it will ignite the fuel mix being pushed out but it won't run (with spark plug screwed in), that was my test for spark and fuel.

    I hope its just needing a new exhaust, and if someone can point me in the direction of one that would be of a higher quality or let me know what I need exactly to get it back up and running.

    In the mean time, (my bike is at the coast so I won't be able to pick it up till this Sunday), I am tearing down an old Homelight XL12 chainsaw I found in storage and will look into making it a friction drive for another bike. Does anyone know how to get the clutch off, I got the first part off but the second inner part looks like it need a special tool with 3 forks to get it off. Is there an alternative to that. I am also looking to strip down an old leaf blower that the pull start has gone out on and some old scooter engines, and may look for a cheap weedeater motor.

    I am looking to eventually have motors on a couple bikes. For commuting to work, I am looking into getting the eBay motor back up and running and mounting a backup friction drive motor on the front wheel. Also going to get a smaller sprocket for the rear wheel for a higher top end speed a I no longer live at the coast will all the hills and need a faster top end speed for commuting on the flats.


    Steven C.

  2. Orpackrat

    Orpackrat New Member

    Guess no ones around, oh well, back to work on the building a friction drive and fixing up the frame mounted motor.
  3. SimpleSimon

    SimpleSimon Active Member

    You sound like a pretty ingenious fellow. We mostly call the eBay kit engines Happy Times engines hereabouts - assuming, of course, that you mean the ultra-cheapo 2 stroke chinese imports. Usually abbreviated HT, those engines were the starting point for most everybody (with some notable exceptions). Many stick with them, others move on to other options.

    In the valley, or over on the coast in Oegon, a friction drive is going to suffer from the commonest problem they encounter regularly - a slipping roller when wet. Which it mostly is, there. That's not too say they won't work - they certainly will.

    On the exhaust system issue, I'd suggest that you check out the ad for SickBikeParts. They sell some excellent after market mods for the HT systems, including a tuned expansion pipe designed for those engines that imcreases power reliably. No, I'm not affiliated with those guys, I just respect good engineering, sound design, and excellent customer service - all of which they provide.

    Beyond that, I'd suggest you read, read, read - the search function on the forums will help you locate info on almost every conceivable question and issue in motorizing a bicycle. There are a lot of good people with amazing creativity and a willingness to share ideas and solutions on this board.
  4. srdavo

    srdavo Active Member

    just a guess.... your main jet might have unscrewed itself. check inside the fuel bowl.

    Welcome to MBc.
  5. Orpackrat

    Orpackrat New Member


    I just spent some time cleaning out the carb and tightening it all. Still not starting. I went to test the basics again, its getting fuel, air, and now its not getting any spark. Wires are all good, the magneto assembly (think that's the name) looks good, just some corrosion but the connections are good:


    How common is it that the coil could go out. I tried a couple spark plugs and still got nothing.

    Any Ideas?