I have a sound that sounds like a metalic rattle coming from the engine area after the bike has been running a while. The rattle seems to increase with rpm's. The sound isn't real loud but it is noticeable. No loss of power or warning lights. The bike has 12,000 on it and it runs great. I have an 81 seca 750. Any thoughts?

Does it change when the clutch lever is pulled in?

Sounds like it might be a stuck camchain tensioner.

It seems to follow the rpms, the higher the rpms the faster the rattle, but it is still present with the clutch pulled in and when the bike is at rest. It is hardley noticable at the low rpm's though. If it is the camchain tensioner, what would the procedure be for adjusting it?

Tensioner

It is on the rear, center, bottom of your cylinder block. Release the jam nut on the bottom of the bolt (the one at the 1 o'clock position in the picture, not the two bolts holding the tensioner to the block), and unscrew the bolt about a turn or two. The tensioner should click into place. If it does not, it may be stuck, or there may be another problem.

Whoops, looks like this is the tensioner assmbly for a 650. The 750 looks like the one on my turbo, according to the cd, inwhich case it is non-adjustable. You can pull off the rear cap, but you will have no luck getting the spring back in afterward. The idea is to get into the tensioner and manually push in the plunger. This will tell you if it is stuck, or out of range of adjustment.

These bikes have dual walled header pipes and rattle when the inside wall breaks loose after years of use. Best way to be sure is to use a mechanics stethoscope with the engine at idle or reved slightly. Place it at the center of the pipe and check each one. If this is the problem it will be apparant on correct pipe.

Alas, my bike too has a rattle. It is coming from the chain hitting the top front of the valve cover. Trying to determine if it is worth fixing as parts are becoming very scarce for the 700 maxim. Bike runs great otherwise. Good luck on fixing your problem