My bike is a DOG AND A PIG, It is ****ing me off, anyone know some other methods?

Discussion in '2-Stroke Engines' started by Bonefish, Jun 16, 2009.

  1. Bonefish

    Bonefish Member

    Bike is still in the break in cycle, and running the fuel/oil mix at 16:1. It now has 225 miles on it. It has hardly any power and is eating gas like there is no tomorrow. It has been like this from day one. Changed spark plug to NGK. Cleaned spark plug, Cleaned out Mufffler(looked good, not much oil), put the e-clip in the second postion from the top on carb. Just fustrated, It revs well when there is no load on the engine(clutch lever pulled in) but when it has a load on it and the wheels are in motion, it lacks power, has very little torque, wouldn't probably hit 20 mph. It fluctuates and has no consistancy or smooth throttle acceleration. Any suggestions or ideas would be apprecaited, Im at a standstill on what else i can to to make this puppy run like she should. The things she does well is, starts, She starts with no problem, and idles well. That is about it.


  2. biken stins

    biken stins Member

    Check filter.
    Is the carb slide going all the way down or sticking ? Adjust cable.
    Take a look at the carb float. May need some tweaking.
    Then the needle will need to be reset.
    Good luck
  3. srdavo

    srdavo Active Member

  4. Mountainman

    Mountainman Active Member

    sorry to hear that -- with such a new engine

    as said above check carb
    compression check just to make sure things are up to par in there
    spark strong ? gap correct ?

  5. Bonefish

    Bonefish Member

    Im at wits end, tried everything i could find in previous threads. Picture of ride.

    Im pulling hair out and about to throw bike off of a bridge.

    This is what i have tried to solve the lack of power/torque problem i have. The bike is very sluggish and will not go over 20 mph. It has 230 miles on it in the break in cycle mixed ratio of 16:1

    1 New plug NGK, nothing
    2 opened carb. checked jett. tight not loose,
    3 cleaned carb.
    4 cleaned carb filter. (was oily but didn't make much difference in performance)
    5 sealed intake port openings where the clamp is at with silicone to prevent air comming in. nothing improved
    6 ran bike with carb filter off. nothing, still boggy and lacks power
    7 ran bike with muffler end cap off, loud as ****, sounded fast but still lacked power.

    Here is a pict. of my Bike. I have the rack on the back to carry an extra gallon of gas and to carry my backpack with laptop in it so my back doesn't get sweaty.

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    copy and paste:

    Thanks for those who have helped, i have been riding a bicycle for 3 years everyday, never driving a car for that period. Pedaling over 5,000 miles a year. I now have this MB and all these problems. It is my only mode of transportation, so i appreciate any help you can give, because i ride this thing everywhere.

  6. What does your plug look like? I would try leaning the fuel/air ratio to 25:1 or 32:1 with a quality oil and fresh gas. Might also have to change the needle clip setting.
  7. srdavo

    srdavo Active Member

    I am sure you mean the fuel/oil ratio.

    16:1 is mighty thick..... I agree.... 25:1 would be a safe fuel/oil ratio, now.
  8. Bonefish

    Bonefish Member

    Thanks, it looks a little charred, with some carbon build up, but not that bad, I cleaned it. reinstalled it, Tried running some Marvel Mystery Oil in the with the gas mix at 16:1 on this last run because i blew my last engine i got from BGF. It had less than 300 miles on it as well so I have been treating this thing like a baby, but it is turning into a red headed step child.

    The engine i got from BGF had balls, it was a rocket ship and had lots of torque and power, before it blew. i noticed this engine i have now doesn't have the slant head but it still should be performing better than it does now. this engine i have now i think is an older model i got from a different supplier that had about 25 of them and sold out quick. It is a heavier engine and the hardware that came with it is better hardware.(screws/bolts) so I kept the engine from BGF as a extra parts engine kit, and have been building this bike using the best parts from both kits.

    The bike had large ballon whitewalls on it, but i had to put skinny tires on it for now because the chain ate the sidewall out. It looked sweet with the whitewalls on it. I hope i can find some 26 X 1.90 whitewalls to replace the original 26 x 2.125's

    Thanks about the suggestion with the changing of the oil/gas mix. Im going to do that after i hit the 300 mile mark, like the break in schedule says, so i don't blow another engine. I always ran the BGF engine with 16/1 though, not sure why it blew. Some guy told me they were throw away engines, so i just bought another one. Hoping that i don't blow another one. This one doesn't seem like it is going to blow, the exhaust pipe didn't even discolor like the BGF engine kit did. So it is not running HOT.

    Anyhow, I'll be ridding it everywhere and should hit the 300 mile mark soon and then wean it to a less oil blend, and hopefully that will solve the problem. I'll update the post after i hit the 300 mile mark and change the oil/fuel blend.

    Thanks for your time,
  9. Yes I did.

    Thanks Dave...........
  10. Skyliner70cc

    Skyliner70cc Active Member

    32:1 is all you need. 16:1 is crazy rich oil mixture and not necessary. I hate to say this, but I have one engine that is like yours. It runs smooth but has no ooomph even with new rings and new head.

    Couple things you can do:
    1. check intake to ensure gasket is not partially restricting intake air.
    2. Pull head. Bottom gasket on the jug is often cut too big and restrictive of the ports.
    3. Pull inline fuel filter that is part of the fuel switch. It often clogs and restricted fuel flow can cause power loss.
    4. Ensure head bolts are tight. Loose head bolts can cause power loss.
    5. Try a new muffler. some of these cheap newer mufflers are overly restrictive. I ahve a box of mufflers that kill engine power.
  11. nadroj

    nadroj Member

    make sure your head bolt are tight, i have seen them come very loose from the factory
  12. AdamT

    AdamT Member

    My bike was running pretty poorly until after messing with everything and no luck i bent the forks in the bowl down a little bit. They are the forks that touch the float in the carburetor. BE VERY CAREFUL not to bend em too much all mine needed was a hair adjustment it runs good now so Im too afraid to bend em more and see what happens. Check your plug after...
    Good Luck
  13. Mountainman

    Mountainman Active Member

    not a bad THING to try

    not a bad THING to try when tinkering with HT engines

    at most times when repairing small engines in the repair shop
    mechanic's ((do not)) do this very often
    but in the case of the HT engines
    may not be a bad idea to try

    only simple note would be in this and most cases when making changes
    remember the starting point
    in case we wish to go back

    so many times in life -- we wish we could go back to where we were !!

    Last edited: Jun 18, 2009
  14. Nitropeewee

    Nitropeewee Member

    had bout the same problem with mine. make sure yer coaster brake isnt draggin or back inner axle nut isnt too tight. good luckaxle
  15. Bonefish

    Bonefish Member

    Many thanks for your ideas, Im now out of the break in cycle and ran my first tank of gas thru it. I ran 93 octane mixed at 28:1 Noticed no difference/to very little difference. I have a speedometer, and made sure the head bolts were on snug before i opened her up to see what she would do. It tops out at 21 mph. Im only 150lbs, so she still should do better. She still is a dog and eats gas. It is very sluggish between 0 and 15mph, after she hits 15 mph and is there for a while and accelerate, she moves, and sounds the best between acceleration, from 15mph to 18 mph. Coaster brake is not on/locked. My next step is im going to try and put the muffler i got from BGF from the engine i blew on it, and was thinking about putting the slant engine head on as well from the blown engine. In doing this would i need to do any thing else besides get a new head gasket and put on slant head? May try tinkering with the carb float forks as well if muffler doesn't work.

    Hoping i might somehow return the favor of the many ideas you have given, hopefully this will help someone that ran into a problem i had, and had to innovate something that worked. It is in regards to the mounting of the gas tank, my bike had a wide/fat top tube and the mounting screws they give me were not long enough to clear and install the mounting brackets, and you can't take out posts and install longer ones like the engine. So i bought some black plastic wire holders from the hardware store and mounted two of them on each tank mounting post. I then ran two long zippie ties at each mount under the top tube of the bicycle. This also allowed a spot for the clutch cable and ignition kill switch wire to run thru. I also added some double sided sticky tape to the bottom of the tank where it fits on the top tube, and it provides a strong secure tank hold without having to drill or monkey around with brackets that will scratch your frame.

    <img src = ""
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    Also check out the post im about to make on a "Quick Release Cargo Trailer" in traveling and commuting. i just got done building it. I built it out of 1/2 inch EMT conduit i got from the Hardware store. It is a strong trailer and also a breeze to disconnet from the bike.

    Here are some picts, more in traveling and commuting thread.

    <img src = ""
    <img src = ""
  16. jtmiyake

    jtmiyake Member

    When I switched my muffler to one with the catalytic converter in it my bike ran like a dog. Barely hit 20mph and had no power. Ran fine otherwise. I fussed with that thing forever drilling out holes in the cat, etc, etc.... I finally gave up and switched back to my rattle can muffler.

    On a different subject, don't trust those zip ties to hold your tank. Zip ties eventually bust.
  17. Have you tried adjusting the clip on the needle inside the carb to lean or richen the air/fuel mixture yet?
  18. I was having a similar problem on a bike i helped build,it would idle and rev but when i gave it gas with a load on it it would fall flat on its butt and id have one heck of a time getting it to move on its own power...It turned out to be flashing in the intake manifold choaking down to about a 1/4 hole to breath through. Cleaned all that **** out and it ran great. Cut off inside muffler tube even with part that comes off, put on 3 rd slot on carb and opened up air cleaner ran 35 with a 44 tooth sprocket.
  19. Mountainman

    Mountainman Active Member

    nice MB
    maybe I am missing someTHING
    where is the swivel point on your trailer ??

    as we ride those THINGS
  20. emdude

    emdude Member

    I read through the posts and agree with all said in regards to getting your motor to run right. I offer the following:

    Based on the experiences I had when I first set up my motor I would not at all be surprised if your engine is running way too rich. Mine was and it took quite some time and work to get it leand out properly. Search past posts by for some further reading.

    One way to get a good idea of this is to run the bike after warmed up on a long straight away and turn off the fuel valve. If there is significant increase in engine speed an power just before it dies from fuel starvation it's time to lean it out. For some reason these engines come set up super fat from the factory.

    I occasionally see this guy ride by where I work and have for a while. His China Girl sounds like a four stroke. It;s pathetic. One day I'll flag him down and offer to help him get it leaned out and tuned up.

    If you have a problem with leagage at the head you will be able to fell it. Just hold your hand around the cylinder head and rev the engine. If there is leakage you will feel he hot gasse on you hand. You should also hear whistling sounds, especially under load up hills.

    I found that a gap about twice the one set from the factory on the spark makes a real difference. If the gap is too small I get misses and a less better reving engine.

    I found that the base gasket covering the transfer ports is NOT an issue. I discovered this before I ever ran the engine but left it as it was. After maybe 2 hours of running time I tore the engine down to fix this. It turned out the covering part of the gasket had simply been eaten away!!!!!. Don't worry about that.

    I know they test run these engine in China an if there anything major wrong like a magneto off and the timing real bad they would have caught it.

    I still think the motor is running way to rich based on my own experience and those of others that have found the same thing.