OMR: '76 KZ900 Restoration/Modification

what signs of damage was seen on the other pistons? do u see any silver specks on the spark plugs insulators ?

Thanks for the link motor...
Round C-Clips, Wiseco part #....

Just curios, what heat range plugs were you running? 8's? 9's?
BS8E's... Brand spanking new out of the box the day before tune up... She ran strong up the hill to Payson AZ ~ 100 miles then 70 miles down the hill.... :blush: :laugh:
The last 30 miles on AAA truck... :pinch:

Have you drained the tank into a clear container and try to see if the fuel is/ was the problem?
Larry and I spoke of this... Other then having it tested not much I can tell from the gas...
Here in AZ, they use the ethanol this time of year...

Prior to coming back down the hill, topped off in Payson, very possible the last fill was improper mix no doubt.... How to prove it... Ah hell who knows...

Life goes on...

Hey Marky...

"do u see any silver specks on the spark plugs insulators"...
Plugs were brand new as well... BS8E's...

Very little on the insulators but on the other 3 piston domes, on the carbon build a slight grayish/silver crystallized misting... YUP!

8's always look good to your eye in that motor in the past? With the compression etc, I think 9's might be the go, not like your going to sit around Idling or putting around with a build like that.
The fuel thing would be very hard to prove, unless other vehicles were effected. We had 26 Cars in one morning towed in from this. That was only one Shop. There were many others at different shops. All because the Truck driver had a Brain Fart.

Yup on the BS9E's... As Larry mentioned, 90F plus outside, run the 9's...

Prior sparkies all looked good throughout the last 3 years... Actually on the rich side where I definitely was cautious of running lean....

Pre-Shitville....
NOTE: Flash was on so seem bright white where actually grayish in insulator color... Never have achieved tan here with our fuel.

Are those in Order, 1 being on the left? As if so there looks like a bit already on #4.

i had seen silver specs on the insulators before. is the first sign on detonation.
thats 1 reason i decreased my squish clearance. havent seen it since.

Old Man Rock wrote: Thanks for the link motor...
Round C-Clips, Wiseco part #....

Just curios, what heat range plugs were you running? 8's? 9's?
BS8E's... Brand spanking new out of the box the day before tune up... She ran strong up the hill to Payson AZ ~ 100 miles then 70 miles down the hill.... :blush: :laugh:
The last 30 miles on AAA truck... :pinch:

Have you drained the tank into a clear container and try to see if the fuel is/ was the problem?
Larry and I spoke of this... Other then having it tested not much I can tell from the gas...
Here in AZ, they use the ethanol this time of year...

Prior to coming back down the hill, topped off in Payson, very possible the last fill was improper mix no doubt.... How to prove it... Ah hell who knows...

Life goes on...

I know for a fact that your local GM dealer should have a tool that can tell how much Ethanol content. Take them about a "piss test cup" full of your fuel and ask them if the could test it for you they should be willing to do so for you. You may want to call ahead and see if the will and have time to though.

"I know for a fact that your local GM dealer should have a tool that can tell how much Ethanol content."...

Ewww, didn't think about that... Thanks Elf, I'll check on that...

BTW, the sparky image isn't the actual plugs removed the day prior. Just an example of previous plugs that was for the most part consistent with those in the image. After 2K miles on them, pretty much the same the last 3 years. More carbon rich then lean conditions.

Consensus of the cause (from me anyways) is high compression pistons, AZ heat index (hell temps) in running her pretty hard (70-110mph) that day (long winding rubberized asphalt roads) and some miss mixed fuel, possibly a faulty spark plug and she went bye-bye. Not to mention a 30 year old engine case/lower end...

If I had just been riding her for someone my age at 65-70mph we most likely would not be having this discussion... But what friggin fun would that be, might as well trade her in for a HD or cruiser then.... Better yet, Honda Rebel... :blush:

elfmagic17 wrote;
"I know for a fact that your local GM dealer should have a tool that can tell how much Ethanol content. Take them about a "piss test cup" full of your fuel and ask them if the could test it for you they should be willing to do so for you. You may want to call ahead and see if the will and have time to though."

That's so they can void the warranty on you!!! If you are using fuel with a heavy mix of Ethanol, and it is not a Flex Vehicle, they won't hesitate to Void your Warranty.

Motor Head wrote: elfmagic17 wrote;
"I know for a fact that your local GM dealer should have a tool that can tell how much Ethanol content. Take them about a "piss test cup" full of your fuel and ask them if the could test it for you they should be willing to do so for you. You may want to call ahead and see if the will and have time to though."

That's so they can void the warranty on you!!! If you are using fuel with a heavy mix of Ethanol, and it is not a Flex Vehicle, they won't hesitate to Void your Warranty.

More for diagnosis then anything, hard to tell exact amount of ethanol content without it and if the vehicle runs bad we need to know if that is an issue. You can also mix some water in 100ml of fuel and watch it separate but takes awhile and the other method is easier.

Motor Head wrote: 8's always look good to your eye in that motor in the past? With the compression etc, I think 9's might be the go, not like your going to sit around Idling or putting around with a build like that.
The fuel thing would be very hard to prove, unless other vehicles were effected. We had 26 Cars in one morning towed in from this. That was only one Shop. There were many others at different shops. All because the Truck driver had a Brain Fart.

Could you elaborate on this some more? I'd like to know what the truck driver has to do with it.

Found this