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What octane should I be using ?
- Requiescat
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1980 KZ750 LTD
I'm getting some pinging around 3000 - 4000 rpm, more when the bike is warmed up.
I've been using premium gas, 91 octane, should I be using a lower grade?
Should I spray some water into the intakes to clean out the combustion chambers?
Should I switch to higher heat spark plugs?
...Or....should I do all of the above?
This pinging is annoying, it's only under load but I'm scared I'm gonna hole a piston. Any advice would be appreciated.
Gregory.
1980 KZ750H LTD more fun than a barrel of monkeys.
have had:
1982 Suzuki GS400L (wadded by an ex friend).
1982 CB 750 Nighthawk(sold to a friend).
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- bountyhunter
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To clean out carbon, do the seafoam thing where you draw it in through a vacuum line until it kills the engine. let it sit about ten minutes, then run it out. You will look like a crop duster for a while when you are riding from all the smoke coming out, usually lasts maybe 15 - 20 minutes.
1979 KZ-750 Twin
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- Requiescat
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Thanks
1980 KZ750H LTD more fun than a barrel of monkeys.
have had:
1982 Suzuki GS400L (wadded by an ex friend).
1982 CB 750 Nighthawk(sold to a friend).
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- hardr0ck68
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- Who put the what in the where?
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1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
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- bountyhunter
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Make sure your mechanical timing advancer is working right. Those suckers gum up and get sticky over time. They can screw up your timing.I was hoping I wouldn't have to buy a timing light. Oh well, I'll see If I can borrow one.
Thanks
1979 KZ-750 Twin
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- 650ed
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1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- PLUMMEN
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Still recovering,some days are better than others.
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- 76 LTD
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- 650ed
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I didn't know KZ750s had such low compression. The stock compression on the 1977 KZ650C1 is 9.5:1. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- Bluemeanie
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Plummen wrote: "no reason why a stock 8.5:1 motor should need 93 octane gas."
I didn't know KZ750s had such low compression. The stock compression on the 1977 KZ650C1 is 9.5:1. Ed
That is correct (9.5:1) compression for our 650's and should be for it's big brother 750 also.
1980 KZ650F1, Bought new out the door for $2,162.98!
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- PLUMMEN
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i guess im used to the john deere tractor compression of a stock 900-1000 :laugh:900-1000 is only 8.7:1Plummen wrote: "no reason why a stock 8.5:1 motor should need 93 octane gas."
I didn't know KZ750s had such low compression. The stock compression on the 1977 KZ650C1 is 9.5:1. Ed
Still recovering,some days are better than others.
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- Patton
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Hi Guys
1980 KZ750 LTD
I'm getting some pinging around 3000 - 4000 rpm, more when the bike is warmed up.
I've been using premium gas, 91 octane, should I be using a lower grade?
Should I spray some water into the intakes to clean out the combustion chambers?
Should I switch to higher heat spark plugs?
...Or....should I do all of the above?
This pinging is annoying, it's only under load but I'm scared I'm gonna hole a piston. Any advice would be appreciated.
Gregory.
If resorting to a different spark plug heat range, would go only one step to a colder plug, and not a hotter plug.
For example, if NGKB8ES is standard, then NGKB9ES is colder, and NGKB7ES is hotter.
The hotter burning plug helps keep it clean under easy riding conditions, such as a riding style of continuous plonking around at lower rpm's and without a regular blast through the gears. Imo, it would tend to increase pinging.
The colder burning plug helps keep temps down under racing conditions or high speed riding for extended periods. It would tend to foul more under "normal" riding conditions.
Btw, does slight application of choke lessen the pinging?
Good Luck!
1973 Z1
KZ900 LTD
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