Honda Big Red - Clunking Chain Drive

[rasum]

I have a 1983 Honda Big Red that uses a chain drive. The ATC is in excellent shape and I use it once a year for hunting moose in northern Alberta. It runs really well but it has an annoying clunk that occurs as the chain goes around. It seems to be one spot on the chain. I oil the chain with 80 weight gear oil. The o-ring chain and sprockets are in great shape showing little if any wear. The chain has been adjusted correctly. The "dull" clunk is heard and actually felt by the rider but my friends on their quads do not hear the clunk. The clunk does not occur as one slows down. The chain skid plate and the chain guard are not bent. One Honda dealer said, "Oh they all make that noise!" However, I am getting tired of the noise and I wonder it anyone has run into the "same" problem.

[Dracus124]

did you try to get a new chain?

[scary132]

Sounds like the sprocket/axle isnt lined up right, or bent, so each time around the chain isnt rolling on right. How are the rear axle bearings? Axle play from worn bearings could cause it too maybe. If the bearings and sprocket are good I would raise the rear end so it is off the ground, loosen the chain, loosen all four bolts for the rearend, then readjust the chain, make sure everything is straight and true, then tighten everything back up.
That would also be a good time to take off and throw away the silly chain guard if you havent already so you can see the chain and sprocket.

[Taiser]

Yep sounds like an alignment problem, or an overly worn chain/sprocket set. If you jack up the rear end and spin the rear tires backward/forwards you should hear the "chunk" better. If it happens more when you spin them backwards then you have an overly worn rear sprocket.

At that age your best off to just change the chain and sprockets. I just did mine and it cost less than 50 bucks on e-bay for all the hardware so it's worth it.

Oh and I'd keep the chain case on, I don't think scary realizes what our Northern Canadian bush is like! :lmao:

[rasum]

Thanks for the replies giving me some ideas to try for the clunking chain drive.

I will have to pursue this during the winter in my heated garage.

I have a set of bearings for the rear axle so I will change them as well.

Thanks to everyone that replied.