QuestionI have two Honda Hawks, 1978, one is CB400T and the other CB400A. The first one has noisy engine caused, I'm told, by loose balancer chain inside the engine. My question is, can I trade out the CB400T engine and stick in its place the engine from the CB400A? I would prefer to keep the engine and transmission that requires manual shifting of gears, but it would be a real project to take out both chains and trade just the chains. What would you recommend?
AnswerKen, before you go to all that work, take off the cover and reposition the balance shaft on the splines. There is a tensioner that is adjustable. You may be able to get it back into adjustment again.
The primary chains are inside the cases, I believe so the motors would both have to be split at the bottom end and parts swapped, assuming that the other engine has better parts than the one you have.
Later versions of the motors had an access hole to facilitate chain adjustments, but not on the 1978 versions.
Get a new gasket and seal for the cover and then dive in and see what you find. This may be easier than you think!
Bill Silver
