No Harm No Foul (plugs)

I have a KZ750 twin. For the past 8 months I unknowingly had BP6ES plugs in, instead of BP8ES. Any chance that did any harm? I rectified the problem this weekend, but was shocked to find the wrong plugs in the bike,

6 is hotter than 8. This doesn't make the engine run hotter, it's the electrode on the plug itself that runs hotter because it's more exposed. If the electrode is too hot plug life will be short because it will melt. Too cold and deposits can build up and foul the plug.

Nessism wrote: 6 is hotter than 8. This doesn't make the engine run hotter, it's the electrode on the plug itself that runs hotter because it's more exposed. If the electrode is too hot plug life will be short because it will melt. Too cold and deposits can build up and foul the plug.

Ah ok. So no harm done. Another question: can overfilling the crank case cause a head gasket leak? And if so, if the oil is drained will the gasket still leak?

Don't think overfilling the oil will cause a head gasket leak.

Nessism wrote: Don't think overfilling the oil will cause a head gasket leak.

I have no idea whats going on then. The leak is such that it drips off the top of the starter - drips down onto the starter. No of this happened before the bike sat our in below freezing temps for a week. Could something electrical have shorted out and affect some kind of pump? The bike was GREAT before it sat in the cold.

Extra cold shrinks metal. Maybe the aluminum casings shrunk enough to break loose from a gasket when the bike was super cold and went through a rapid heat cycle from running. Back when I stored my bikes in a heated basement, I never had leaks. Ever since storing in a cold garage, I've noticed tiny little leaks showing up where they never did before.

loudhvx wrote: Extra cold shrinks metal. Maybe the aluminum casings shrunk enough to break loose from a gasket when the bike was super cold and went through a rapid heat cycle from running. Back when I stored my bikes in a heated basement, I never had leaks. Ever since storing in a cold garage, I've noticed tiny little leaks showing up where they never did before.

Yeah I think thats what happened. it got EXTREMELY cold the past few weeks and I made the mistake of letting the bike sit. Now its back in the heated garage. Any change it will expand again? I know changing a head gasket is a big job. I dont have the time but i do have the money to get it fixed. How much should that run?

Try re-torquing it first before replacing the head gasket. Use the specs and torquing pattern in the manual.


Good Ridin'
slmjim & Z1BEBE