butre
Well-Known Member
easy on the power? no, full throttle heavy load all the time. never hold top speed for the first 5 miles
Need help with gas/oil
- Thread starter Greendice34
- Start date
sbest
Active Member
I do not know for these engine, but I have thousands of kms of experience riding my 2000 KTM 125 EXC in dirt and on the highway.
I have tuned the 125 engine to run on 87 octane, I might have lost one or two HP, but worth it to run on any fuel I can find. With the highway tire and sprocket pictured below it has a top speed of 140 kph (87mph) and can do any highway grade at 110 kph (68mph) although I tend to keep it to 100 kph because of the rpm. My point is, I am very familiar with putting huge miles and high speeds on a small 2 stroke engine.
This bike had 40:1 synthetic oil for the first year of its life and 50:1 thereafter. I ran most of a tank of 100:1 through it one weekend. Bonehead math error. No bad effects. I have had 2 engine failures in the 15 years I have owned this bike. At 7 years I dunked the bike, completely, in muddy water. Broke rings, drove it home with no rings. Had to push start and it wouldn't idle but it made it 15 kms to the trailhead with zero compression. You cannot kickstart, it is a push down a hill sort of thing. Actually I dunked it annually at the same event 2 more times before I finally needed a new crank and cylinder. The other failure was a forged piston that was not allowed to warm up properly. Gave it full throttle after only a 1 km warm up and it locked up and set me on my butt. Or rather wore the skin off my butt. My point? 15 years and many thousand kms at 50:1 and no oil related failures.
The head on the right was my high mileage 50:1 lean jetting head:
Note the differences in combustion chamber shapes. The one on the right (and middle) is a mid-range torquer.
The one on the left is a high rpm screamer. Oh yeah, my point? Less oil is better.
Steve
I have tuned the 125 engine to run on 87 octane, I might have lost one or two HP, but worth it to run on any fuel I can find. With the highway tire and sprocket pictured below it has a top speed of 140 kph (87mph) and can do any highway grade at 110 kph (68mph) although I tend to keep it to 100 kph because of the rpm. My point is, I am very familiar with putting huge miles and high speeds on a small 2 stroke engine.
This bike had 40:1 synthetic oil for the first year of its life and 50:1 thereafter. I ran most of a tank of 100:1 through it one weekend. Bonehead math error. No bad effects. I have had 2 engine failures in the 15 years I have owned this bike. At 7 years I dunked the bike, completely, in muddy water. Broke rings, drove it home with no rings. Had to push start and it wouldn't idle but it made it 15 kms to the trailhead with zero compression. You cannot kickstart, it is a push down a hill sort of thing. Actually I dunked it annually at the same event 2 more times before I finally needed a new crank and cylinder. The other failure was a forged piston that was not allowed to warm up properly. Gave it full throttle after only a 1 km warm up and it locked up and set me on my butt. Or rather wore the skin off my butt. My point? 15 years and many thousand kms at 50:1 and no oil related failures.
The head on the right was my high mileage 50:1 lean jetting head:
Note the differences in combustion chamber shapes. The one on the right (and middle) is a mid-range torquer.
The one on the left is a high rpm screamer. Oh yeah, my point? Less oil is better.
Steve
HeadSmess
Well-Known Member
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oil? pffft. the finest swiss butter, if you will. made with real swiss cow cream, educated in geneva and trained in all the fine arts. the cow AND the cream that is.
all mellowed with some overproof motor spirit imported from the far middle east, blended with virgin first pressing castoroil and menthol for that refreshing aroma we all know and love
the exact specific formulae remains a family secret, closely guarded from the fiercest of rivals.
all mellowed with some overproof motor spirit imported from the far middle east, blended with virgin first pressing castoroil and menthol for that refreshing aroma we all know and love
the exact specific formulae remains a family secret, closely guarded from the fiercest of rivals.
butre
Well-Known Member
My family recipe is avgas and whatever cheap oil the oreilleys or autozone carries mixed at 50:1. usually that stuff that says low smoke on the bottle but really smokes like a steam engine
sbest
Active Member
From experience, I usually go the other way around. I build the engine to use the available pump gas and use the best oil I can find.
Fuel, you use a lot of and are often forced to use what the pump has. Build the engine for it.
Oil, you use a little of it and is critical to the long term health of the engine. Better oil is cleaner, lubricates better, and MOST importantly, less prone to fouling the plug.
If, perchance, you cannot find good oil at a backwoods gas-stop, one tank of cheap oil will not kill your engine.
One tank of 87 octane fuel will kill an engine built for 100 avgas.
$12 for a litre of good synthetic oil figures out to 72 cents in a tank of fuel.
Cheap oil is a poor way to save 54 cents, especially if you are doubling up on it to "stay safe".
Steve
Fuel, you use a lot of and are often forced to use what the pump has. Build the engine for it.
Oil, you use a little of it and is critical to the long term health of the engine. Better oil is cleaner, lubricates better, and MOST importantly, less prone to fouling the plug.
If, perchance, you cannot find good oil at a backwoods gas-stop, one tank of cheap oil will not kill your engine.
One tank of 87 octane fuel will kill an engine built for 100 avgas.
$12 for a litre of good synthetic oil figures out to 72 cents in a tank of fuel.
Cheap oil is a poor way to save 54 cents, especially if you are doubling up on it to "stay safe".
Steve
butre
Well-Known Member
avgas isn't too hard to come across around here, and I always keep a few gallons spare. avgas is still leaded, if you've ever used leaded gas you know what kind of lubricity benefits it has compared to unleaded gasoline. remember when unleaded gasoline first came around and everything that was already on the road needed the valves lapped every couple of years? that's because the tetraethyllead in leaded gasoline kept the unhardened mild steel valves from wearing down.
I don't use avgas for the octane rating, I use it for the TEL. my bike will happily run on 93 octane if I throw a splash of xylene in there
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