Engine Trouble 80cc ht won't start

Discussion in '2-Stroke Engines' started by rider30ab, Aug 13, 2012.

  1. rider30ab

    rider30ab New Member

    Hello. new here and any help would be great! first build and got engine and parts new. Installed motor and parts then went to fire up and nothing. not a thing. got spark but seems very light even with ngk b6hs plug. piston moves when plug is out and i am assuming when plug is in. the weird thing is is when pedals are being cranked there is not one sound of the engine even trying to turn over. no popping, no nothing! I looked at specs on the cdi. output on wires and mine isn't anywhere close to the specs. yet i am still getting some spark. like i said, very faint. magneto is good(all readings are right on with those specs i received. been at it for a week. any help would be great. going crazy here! thanks
     

  2. Big Red

    Big Red Active Member

    Can you tell if the engine is turning over, or is the clutch slipping and just nothing happening? If the clutch is engaging properly then it should turn the engine over. If not, then it needs adjusting to engage the engine.
    You should at least be able to hear the engine's compression making a little noise through the exhaust and carb. It should be hard to push from a standstill with the clutch out. Check the flower adjust nut on the clutch, I've heard a couple guys got engines with stripped flower nuts. This would make the clutch way too loose and simply slip.
    Let me know if this helped.
    Big Red.
     
  3. rider30ab

    rider30ab New Member

    thank you. will definately try tomorrow.
     
  4. Big Red

    Big Red Active Member

    Clutch?

    I'm going to try to further describe how the engine and bike SHOULD act together as a unit.
    Of course, with the clutch lever pulled in the rear wheel should roll freely, letting the motor chain spin free around the engines drive gear.
    When the lever is let out it should almost lock the rear wheel, but not quite really. It should make the rear tire skid if no weight is on the bike. With a little weight on the bike it will lock the tire to the pavement thus forcing the wheel to spin and in turn, making the engine turn over. When this is done you should hear the engine making a noise like Thunk, Thunk, Thunk. This is the piston coming to the top, making compression, getting past it, then coming around to do it again. So it's either the Thunk noise or a running engine.
    If all you're getting is a little drag on the rear wheel and no "Thunk" then your clutch is probably slipping. If this is the case then you can either do a search on clutch adjustment, (recommended,) or get back to me and I'll talk you through it.
    Big Red.
     
  5. pedalman

    pedalman Member

    Not sure if this can help, but when I got my bike the clutch was totally stuck(it didn't help that I had nothing to compare my bike to, nobody I knew had one) and I didn't know what the heck was going on....I had to knock it with a hammer to get it unstuck. Those kits sitting on a ship from China then sitting in a warehouse for long periods could cause this I was told.
     
  6. Big Red

    Big Red Active Member

    Get a BIG hammer.

    Thats right pedalman, If it don't work:idea:, hit it with a hammer:jester:
    Any particular area this force should be applied?:devilish:
     
  7. Big Red

    Big Red Active Member

    If the clutch was stuck then the engine would not turn over, not even with the spark plug out. The clutch is turned by the small bevel gear from the crankshaft. Then transfered to the drive gear shaft through the clutch assembly. If the thing turns over when the plug is out then it is probably a slipping clutch. The extra pressure of compression on the clutch assembly is too much on a loose clutch to turn over the engine.
     
    Last edited: Aug 14, 2012
  8. rider30ab

    rider30ab New Member

    The engine turns over with the plug out. For sure.
    When I pull the clutch lever in the rear tire turns freely. For sure.
    Without the lever pulled in the rear tire will not turn without me on the bike. The rear tire drags.
    When I'm on the bike and pop the clutch going down hill the rear tire turns just like it should when trying to fire. EXCEPT the engine doesn't fire. No pop, nothing.

    I put gas in the plug hole and tried to kick start the engine. Nothing
    I put gas in the intake manifold. Nothing

    All of this has been done with the original ignition coil and a new one. The spark plug is getting fire.

    ??????
     
  9. Big Red

    Big Red Active Member

    Then it acts exactly as it should except no "pop". I'm sittin here thinking my A** off. Coming up blank.(Wait a minute, here I go.)... Are you using the spark plug that came with it? Also the plug wire that comes with these things are carp.It could be a weak and defective CDI unit. If you're still not getting the voltage specs required out of the CDI then that is likely your problem. a weak spark will give you fits couse it looks like yer gettin spark, right? But you would have to run it downhill at 50mph to get it to start. A weak CDI can do the same thing as a weak coil. Spark LOOKS OK, but no go. Since you've replaced the coil, the next things are the CDI, plug and wire. A good auto type wire will work and get yourself a NGKB6HS plug, (Part# NGK7534.) If this don't do it then I'm outa suggestions.
    Big Red.
     
  10. pedalman

    pedalman Member

    I mean't clutch stuck in engaged position--not totally frozen engine,sorry for misunderstanding. It wouldn't disengage.
     
  11. Big Red

    Big Red Active Member

    AND, OH YEAH. Unhook yer kill switch. If it's defective then it'll never start.
    Big Red.
    P.S. Just noticed in yer first post you said you have a NGKB6HS, Sorry for being slow. So just get a new CDI unit and a good plug wire. I THINK this will do it.
     
    Last edited: Aug 17, 2012
  12. rider30ab

    rider30ab New Member

    Unhooking the kill switch is the first thing we did. I remembered that from my dirt bike days. Now clear something up for me: I am calling the little black unit with the plug wire coming out of it the CDI and also call it the coil. Is this not right? What part are you calling the coil? Help me get on the same page you are on. I'm easy, just point me where you want me.

    We are currently using a new CDI unit (black with plug wire)

    Thanks for the help !!!!
     
  13. motorpsycho

    motorpsycho Active Member

    how are your wires connected together?
    if you're using the push together connectors that come with the kit, cut them off and throw them way. solder and heat shrink all of your wire connections.
    do you have anything (like a headlight) hooked to the white wire?
    if so, remove it.....cut the white wire and cap it off.
    make sure that there are no bare wires touching anything.

    have you tried to start it using the choke?
    have you removed the air filter to verify that your choke is open or closed?
    are you sure that you have fuel flowing into the float bowl of the carb?
    yes, i know that you poured gas into the eingine and into the intake manifold.
    but if you put too much in, it will just foul the plug and it will not run.
     
  14. rider30ab

    rider30ab New Member

    1- wires hooked together with screwnuts
    2- no headlight, no wires touching anything
    3- Tried with choke on and off,,,many times
    4- removed air filter and checked operation of choke,,,,many times
    5- open drain screw on float bowl and watched gas come out,,,,,many times
    6- checked plug for fouling. plug clean and dry,,,,many times

    Thanks for the check list, it made me stop and think.
     
  15. Big Red

    Big Red Active Member



    The CDI is the little black box with the plug wire. The coil is the part that goes around the magneto (magnet) with the copper windings and the black, blue and white wires coming from it. You said you replaced the COIL. If you have not replaced the COIL then do so now. That is usually the first weak link. Even new they are often defective. I would almost put money on it that this is your problem. I THOUGHT you had already replaced it or that would have been the first thing I suggested. I have had MANY bad coils that still put out spark, just not strong enough to start the engine. Took me a minute to figure it out also, so don't feel too bad about it. I've even replaced a bad coil with what I THOUGHT was a good one, (it wasn't,) and almost lost my mind trying to figure it out. The coil is located under the cover on the left side (sitting on bike) of the engine. The coil has four screws holding it to the inner case. Easy as 123.
    http://www.ebay.com/itm/66cc-80cc-M...Cycling_Parts_Accessories&hash=item2c60a2d240
    Big Red.
    P.S. While looking at coils I noticed that some sellers call a CDI a coil. THIS IS WRONG.
     
    Last edited: Aug 17, 2012
  16. Big Red

    Big Red Active Member

    Hey Moto, All good advice, But I'll betcha a million, gajillion dollars it's his coil. Been through it a million, gajillion times.
    Good to run into you again BTW, It's been a while.
    Big Red.
     
  17. BigBlue

    BigBlue Active Member

  18. Big Red

    Big Red Active Member

    Last edited: Aug 17, 2012
  19. BigBlue

    BigBlue Active Member

    10-4 good buddy!

    Chris
    AKA: BigBlue
     
  20. rider30ab

    rider30ab New Member

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