HELP! with engine sprocket/chain issue

Discussion in 'Frame Mounted Engines' started by Danuaro, Apr 3, 2009.

  1. Danuaro

    Danuaro New Member

    After finally overcoming many previous obstacles, I have managed to get the chain onto the bike. However it seems that the spacing between the teeth on the engine sprocket and the chain does not match up. This causes either one of two things.

    A) The chain does not mesh up and pops off the sprocket, resulting in its getting wedged between the sprocket and the engine housing. Illustrated in picture 1.
    B) The chain gets forced down between the teeth of the sprocket. It then has problems releasing from the teeth as shown in picture 2.

    Picture 3 shows both of these issues going on. The chain on the top is not lining up and the sprocket tooth is hitting the chain roller. The bottom chain is hung up on the teeth, which requires a surprising amount of force to pull off.

    I purchased both the engine and chain from Dax in one of his kits, so it seems strange that they do not match up. I am hesitant to put a grinder to the sprocket to grind the teeth down, but see no other solution. I could not find any other posts in which people were having similar problems, so if anybody has any hints, they would be greatly appreciated.

    Attached Files:

  2. DetonatorTuning

    DetonatorTuning Active Member

    from the pics, you might lightly file the sides of the sprocket to get that curl of machine kurf off. see it down in the "bellies" between the teeth ? that may be what's causing the chain to hang on the sprocket.

    you may also have so stiff link issues with that chain. that may be causing the bunching problem.

  3. Danuaro

    Danuaro New Member

    Well, I have filed the kerf off and that does not seem to help any. The chain is also quite flexible with no spots that do not pivot freely.

    I do think that it is the teeth that are to long or the spacing between them is to large for the chain to handle. I just might have to bring out the rotary and grind a little off of the ends of the teeth, maybe round them off a little. Cross your fingers!
  4. srdavo

    srdavo Active Member

    looks to me, like you need to snug your chain up some....a chain too loose, makes it do funny things......have you ask dax??
  5. fetor56

    fetor56 Guest

    Something seems WAY out....if the chain fits fine on the rear sprocket i can only assume the front sprocket is the culprit.
    As suggested before ask Dax,or if u can get your hands on a KMC K910 Kool Chain that's known to fit HT sprockets perfectly.
    Ask Duane first,it's his kit.
  6. HoughMade

    HoughMade Guest

    That's what it looks like to me. The chain clearly fits around the sprocket as can be seen in pic #2. If it were tighter, it would get "pulled" off of the front sprocket, though rounding a hair off of the edges of the teeth could not hurt.

    HERPER Member

    lube it up with some grease.. and recheck for tight spots that dont pivot. or just tighten the chain with the tensioner tighter... this could be from slack in the chain


    First what size is your chain? #415 is Ideal, but not 415H, 420, or 410. and you can try buying a new chain from 'boygofast' on ebay and a new sprocket from kingsmotorbikes. might be worth a shot!
  9. V 35

    V 35 Member

    Picture # 2 looks like loose chain, my advice, put chain on slack, no tensioner,
    do not use spring clip on master link !, at least, not yet . With chain on both sprockets, remove spark plug, or lock clutch, so engine turns easy. Try turning rear wheel a little, either forward or backward, see if chain ' takes a set ' and seats properly. Next, check wheel alignment, both chains must be true, a cocked wheel makes the difficult more so. Push bike around, be sure chain turns freely, if hard to push = chain is too tight, loosen until it pushes easily. I'm running # 415 chain on both sides of my cruiser.
    Last edited: Aug 18, 2011