High-altitude suggestions for stock KZ440 engine?
- Astrin
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bluej58 wrote: What Octane gas are you running?...
JD
Well, 90 here when I use pure gas, because that's all I've got here, at one single place, a terminal by the airport. But I don't know why higher-than-spec octane should matter. It's not like it retards detonation. It prevents PRE-detonation at high compression. I've never experienced any difference running higher-than-spec octane on a vehicle. Some say that my SV650 will run better on 87 than on 91 but I've never experienced any difference on the track.
Pure gas isn't only about preventing ethanol from dissolving rubber (although that's critical in my BMW - while modern bikes use Viton (R) which is ethanol-resistant). It's also about water retention in the fuel. As you know if you've ever mixed a drink, ethanol dissolves in water and vice versa. Ethanol will adsorb water, when filling on a humid or rainy day or whatever, and that can freeze or just be a problem. Many folks with modern bikes advocate using pure gas for that reason. But it's dry in Santa Fe, so I'm not too concerned about that. I have filled the Kawi with 88 E10 here, I think it was, but I'll try 86 E10 for comparison. But it's mainly about the mixture, I think, for the normal reasons. There ain't much air here.
Sam Hokin - Santa Fe, NM
1991 BMW K75RT road | 1983 KZ440 cafe toy | 2006 SV-650 track
"BMWs are slugs, for gentleman riders who are also slugs." -- letter to Cycle World, 1984
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- redhawk4
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One tip with your fuel tank, that I do with my cans of gas, is to always put fuel stabilizer in there when you fill up at the gas station, that way everything you put it in is automatically ready for winter lay up, whenever that occurs, as opposed to trying to get all that done when you finally realize you won't be riding a gain until spring.
1978 KZ1000A2 Wiseco 1075 kit
1977 KZ650B1
1973 Triumph Tiger TR7V
1968 BSA Victor Special 441
2015 Triumph Thunderbird LT
1980 Suzuki SP400
Old enough to know better, still too young to care
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- Astrin
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redhawk4 wrote: I use 88 octane non ethanol gas in all my bikes. Even though the BMW says I need 91 it runs fine on the 88 and gets better mpg than with ethanol gas.
One tip with your fuel tank, that I do with my cans of gas, is to always put fuel stabilizer in there when you fill up at the gas station, that way everything you put it in is automatically ready for winter lay up, whenever that occurs, as opposed to trying to get all that done when you finally realize you won't be riding a gain until spring.
What's "winter lay up"? Yeah, I use Sea Foam pretty generously. Keep those injectors clean. My K75 vibrates on low octane, my wife even notices it immediately. Even 93 is noticeably smoother than 91. But the K75 is an insanely smooth engine, so these little changes are noticeable. Pure gas mileage is significantly higher, more than the 3% minimum you get just from energy considerations. (Ethanol's specific free energy is significantly lower than that of petroleum.)
Sam Hokin - Santa Fe, NM
1991 BMW K75RT road | 1983 KZ440 cafe toy | 2006 SV-650 track
"BMWs are slugs, for gentleman riders who are also slugs." -- letter to Cycle World, 1984
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- redhawk4
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1978 KZ1000A2 Wiseco 1075 kit
1977 KZ650B1
1973 Triumph Tiger TR7V
1968 BSA Victor Special 441
2015 Triumph Thunderbird LT
1980 Suzuki SP400
Old enough to know better, still too young to care
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- SWest
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- 10 22 2014
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Steve
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- Astrin
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redhawk4 wrote: If you were in Utah at 7,000 feet, you would know what winter lay up is, unless you have snow chains and can handle 2 feet of snow
Heh. I'm gloating. We just moved from Wisconsin, my home state, where winter lay up can be rather lengthy. Usually December through end of March for me. Although one member of our BMW Club rides through the winter on her GS, saying "the season ends on December 31 and starts on January 1." The glory of Santa Fe is it's a quick drive up to excellent snow, especially this year. The skiing has been fantastic.
Sam Hokin - Santa Fe, NM
1991 BMW K75RT road | 1983 KZ440 cafe toy | 2006 SV-650 track
"BMWs are slugs, for gentleman riders who are also slugs." -- letter to Cycle World, 1984
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- SWest
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- 10 22 2014
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Steve
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- Astrin
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1. As i was toodling around the hills, I found that the bike was really dogging it up hills. So, I pulled the foam "air filter" out of the airbox. BIG improvement. No surprise, the bike was starving for air when it needed it. So, I've replaced the foam, but I thinned it out in several places so the bike can get more air, while still having some dust protection. I'm sure there many higher-flow replacements for the foam, but this seemed to work well. This also made a huge improvement to starting the engine.
2. As I got to a very low tank, which had been 90-octane E0, I tried a suggestion here and put in 86 octane (E10). MAJOR difference. I'd cranked the idle up with 90, and now I had to turn it back down to about where it used to be at sea level. It also idles much more reliably around 1100 RPM. I think this improved starting quite a bit as well. So 86 octane it is. (It's very dry here, so I'm not too concerned about the water retention of E10, which was a major issue in humid/damp Wisconsin.)
3. I got a new gel battery. This was already planned, but of course it cranks better while providing more volts. The bike started much better with the above improvements, but now it starts right up, and I can use the choke.
So I'm in business without re-jetting, and the bike's running great! Thanks for all the tips!
Sam Hokin - Santa Fe, NM
1991 BMW K75RT road | 1983 KZ440 cafe toy | 2006 SV-650 track
"BMWs are slugs, for gentleman riders who are also slugs." -- letter to Cycle World, 1984
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- missionkz
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In a normally aspirated, internal combustion engine, it's actually closer to 75% max power above 7,000 ft and only 60% power at 10,000 ft.swest wrote: Oh, I should have said you should expect 10% or more less power at high elevation anyway.
Steve
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
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- SWest
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- 10 22 2014
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Steve
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- missionkz
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Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado
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- KZB2 650
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1978 KZ650 b-2
700cc Wiseco kit 10 to 1.
1980 KZ750 cam, ape springs, stock clutch/ Barnett springs.
Vance and Hines Header w/ comp baffle and Ape pods, Dyna S and green coils, copper wires.
29MM smooth bores W/ 17.5 pilots, 0-6s and 117.5 main
16/42 gearing X ring chain and alum rear JT sprocket.
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