Chains 2 stroke chain popping off

Discussion in 'Transmission / Drivetrain' started by DoIt AllPauls, Feb 7, 2013.

  1. DoIt AllPauls

    DoIt AllPauls Member

    I have a 2 stroke kit the chain keeps popping off .
    The engine sprocket , spoke sprocket and back tire are all aligned and are true.
    The engine is not moving
    I have adjusted the tensioner, tighten the chain where it is not to tight or to loose.
    I can ride it sometimes for days with out it popping off then other times it might pop off 2 -3 times a ride what could be wrong?

    :confused::confused::confused::confused::confused::confused::confused::confused::confused::confused:
     

  2. Fabian

    Fabian Well-Known Member

    What about the option of simply moving up to a better drive system like the SickBikeParts shift kit, and be done with chain misalignment issues; commonly noted with a single speed system.
     
  3. DoIt AllPauls

    DoIt AllPauls Member

    I purchased it at a garage sale to fix and sell so i don't want to put a lot of cash in it.
     
  4. geebt48cc

    geebt48cc Member

    Understrand Doit.............#410 0r #415 chain?
     
  5. crassius

    crassius Well-Known Member

    first, be sure the chain is at its tightest spot in its rotation before adjusting it, then roll it a bit to see how loose it gets at loosest spot - you may have to straighten out the rear sprocket a bit if it gets too loose

    also, I like to grind the top edges of the sprocket teeth to a sharp point so they will more easily find the center part of the link
     
  6. DoIt AllPauls

    DoIt AllPauls Member

    don't know for sure but I bet it's a 410.
    How do you tell
     
  7. Samdallas214

    Samdallas214 Member

    I had one that was doing the same thing and come to find out it was the chain itself,
    your engine is a 5+ year old used engine with the original chain, and a new sprocket.
    I told ya last time it happened it almost has to be the chain count the links and order a new 415 chain. just spend the $20.00

    everyone should know Paul is beyond cheap, I thought I was a cheapskate and a tightwad, Paul's is even a bigger cheapskate and tightwad then me and that's realybsaying something.
     
  8. geebt48cc

    geebt48cc Member

    Well, the 410 is the same size as regular chain on bike. D, if chain is tight, and true...............then make sure every link is turning ok, and lubed! If the rear sprocket teeth are turned a bit either way when entering chain, it will jump off. Make sure sprocket teeth are mating straight on sprocket. Even if it looks straight, the rear wheel can have the sprocket turned just enough to throw off!!
     
  9. Samdallas214

    Samdallas214 Member

    geebt48cc, all have been checked and rechecked ,
    what I thank it is the chain is old and bends real easy and need to be replaced.
    when he got it it has a lot of rust on the chain 90% coverage , Paul thought it was the sprocket so I gave him a new one, that did not fix it .
    I thank he has a 415 ordered.
     
  10. geebt48cc

    geebt48cc Member

    Mmmm, Ok, I see. Sam, from what I understand, the 415 should help. The larger size, gives a bit more room in travel.
     
  11. crassius

    crassius Well-Known Member

    410 is 4/8inch from pin to pin, 1/8 inch gap inside - 415 is 4/8inch from pin to pin, 3/16 inch gap inside (the '15' is 1 & 1/2 8ths)
     
  12. DoIt AllPauls

    DoIt AllPauls Member

    After doing all y'all told me to do and nothing fixing it it has to be the chain,
    I will be ordering a 415 off ebay today, went to the bike shop they wanted almost $40USD pluse tax for a new chain .
    Ebay has them heavy duty for half as much.
     
  13. DoIt AllPauls

    DoIt AllPauls Member

    The chain was it problem

    I got the new chain installed and wow what a difference no more slipping no more popping off .
    I was able to put it up for sale this week end and a new member named Tom purchased it for the $175.00 I was asking .

    As always your guys rock and as all ways you guys knew what was wrong , and how to fix it thanks

    motoredbikes.com and there members are a great bunch of people regardless of what troll bobs says

    :bowdown::bowdown::bowdown::bowdown::bowdown::bowdown::bowdown::bowdown::bowdown:
     
  14. Fabian

    Fabian Well-Known Member

    Interesting to note that for all of Mr Bob's claims of assistance to others on this forum, and his good standing by those who value him greatly, he not only has "zero" reputation points, but lacks a messianic fan club to back up his claims.
     
  15. roughrider

    roughrider Member

    Hmmm...

    OK brother, I gotta be honest. You SAY it's all straight, true, and tight, but if that were true, you would not be throwing chains.

    1. Tight. Really? REALLY? Is it tight in one part of the revolution then loose in another? If so, you have a gear that is either out of round or not mounted concentrically.

    2. Alignment. Looking at the chain from the rear, is it really in a PERFECT line? Not even a little itsy bitsy offset?

    3. Wobble. No wobbles in the rear gear? Try spinning it with a marker held next to the gear. Does it "kiss" one section and then have a tiny gap?

    4. Concentricity. Is it really, REALLY concentric. I suspected this earlier, but here it is again. "Out of round" makes the chain loose, tight, loose, tight. That, combined with a worn chain could cause your trouble.

    Bottom line, tight and "true" = no chain throwing. Period.

    If all of the above are cool, you have a chain (or gear teeth) that is/are so worn you need to replace one or the other. Looking very, very, VERY closely at the drive gear and the rear gear, do you see any teeth that look chewed up? Bent? That would do it.

    BTW, the stock chains on the the newer builds are all 415s. 410s are a touch narrower. I doubt that's your problem. But a really worn chain is just so sloppy it can flop around from side to side even if everything else is OK. That WOULD do it, but even then, only if it were not tight. (And I mean TIGHT.)

    Just my 2 cents and what I'd look for if I had your bike to examine. To repeat, "trueness" means three axis: alignment, wobble, and centricity.

    Cheers,
    Rick
     
  16. DoIt AllPauls

    DoIt AllPauls Member

    First thanks for the advice/help roughrider all you suggestions were tried and tried and tried.
    you should know i purchased the MB used, although the engine was a little dirty it was rapped up with a small tarp.
    The tarp covered the engine but the chain was not covered and was rusty, as far as being true you could not of gotten it any straighter,
    Sam tried to tell me the chain was worthless and was not worth spending the time to clean all the rust off of it.
    I was told it was a wast of time because I had no idea how long the chain was rusty ,the rust had probably weakened the chain.
    The bike came with a little box of parts 99% of them were worthless junk but there was 5 new rust free master links, I just thought the new free links would fix it, truthfully I was just to cheap to spend the $20.00
    I know the chain was bent I replaced the bad ling, worked fine for around a week then the chain popped off again I found another bad link i replaced that link worked fine for around another week after the 5th link I just gave up a spent the $20.00, I should of spent in the fist place.
    a lesson well learned not to be so cheap. LOL
    Since I replaced the chain I rode it every day for 2 weeks with no problems, I then sold it to Tom he has had it for around 2 week now.
    After 4 weeks of daily use the chain has not popped off, not even once so it had to be the chain.
     
    Last edited: Feb 27, 2013
  17. Fabian

    Fabian Well-Known Member

    This is an interesting topic because i have had some interesting experiences with chains and how they misalign and hence derail.

    Prior to fitting my chain tensioners on the SickBikeParts shift, the jackshaft chain could be made to reliably derail, even when the chain didn't have a lot of slack and both sprockets were in perfect alignment; verified with a straight edge.
    If constant tension was applied to the chain, and the bike traveling along absolutely strait, the chain would happily spin around, but if throttling off and back on again in an aggressive manner, over uneven surfaces and throwing the bike around, the chain would derail.

    What seemed to be be happening is that the aggressive on-off throttling caused an oscillation from the sudden change in tension (from a slack state); a bit like cracking a stockmans whip.
    The engine would also flex a little on the engine mounts, causing the jackshaft to twist downwards, creating an increased level of momentary chain slackness.

    After i installed my chain tensioners, the problem "never" reappeared, no matter how aggressive i was with the throttle or how bad the road surface; also surprising was the noticeable reduction in chain induced vibration; most of it coming from the 415 chain on the left hand side, which madly flapped about because of the non concentric Chinese output shaft sprocket.
    The left hand side chain tensioner massively reduced this medium frequency vibration.
     
  18. roughrider

    roughrider Member

    Yep. I agree with this verdict. I have had success reviving rusty old chains by alternately soaking them in motor oil and scrubbing them with mineral spirits. But that won't help a chain that's just, plain, worn.
     
  19. roughrider

    roughrider Member

    I have seen this on other machines. It can even happen on fixed gear bicycles. This shows that there's nothing like a springed tensioner on chain drive which gets hit hard by sudden accelerations and de-accelerations. That's what I take away from that.
     
  20. Samdallas214

    Samdallas214 Member

    I tried to tell him if it's a chain that might have a little rust or one you at least know how old it is and how long the rust has been there, You can probably fix it , but a used MB with a rusted chain just replace it.

    O by the way the easy way to remove rust, just soak it in a can of coca cola over night, the next morning the rust will be gone.

     
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