Water pump/tach issues.

[jkevinlilly]

This evening was good, riding down the "Cherry-Cola" Skyway on Pinky (74 GT750), when all at once I heard a sound from the left side of the bike like the kickstand hitting the road. Regretfully, that was not the issue. Tach immediately stopped working, and temp started to climb. I limped back to basecamp two miles at a time, letting the bike cool in between. Longest 12 mile ride I have ever taken.

My guess is the plastic water pump gear ate itself. Opinions please.....

Kevin

[Suzsmokeyallan]

Yup sounds plausible, you'll need to pull the cover to confirm the issue.

[tz375]

Clearly something broke between the crank and the tacho gear. It is most likely to be that plastic gear but it's possible that the drive gear on the crank fell apart or the quill shaft snapped, but they are less likely than the plastic gear.

Grab a camera and pull the side cover off.