Backwoods M Max
New member
I am wondering what the tolerance is to elevation, temperature and the jet needle?
I had set my needles at 3.5 the first year that I owned the sled and run it that way ever since, the plugs had good burn on the ground but the color was always on the black side. I did that out of worry with ethanol fuel and was always running 91 ethanol out of safety since I didn't trust 89 with ethanol in it to be close enough to Yamaha's 88 octane spec.
I have moved now and can get 91 ethanol free from a station that's trail side. It's my fuel source of choice now and I'm not too worried about low turnover. I want to set my needles back but am wondering where to go. Torn between 3 and 2.5. The elevation at the new house is 675' and anywhere I go to ride is just going to be an increase in elevation. I'm realistically in between the 300-1700 and 1700-3300 foot tuning columns for the MM700 when I ride. Most rides will start at or just below 1700' and end the day above it, but never going over 3300' From 20F up I'm at 2.5 on the needle through both columns, I don't need to be at 3 until I'm below 0F in the 300-1700 column.
I have read that all sleds, not just yamaha are jetted rich from the factory which I completely understand. How does this tolerance carry over with the jet needles? If I end up starting the day between 0F and 20F where it calls to be jetted at 3.0 and I'm at 2.5 even though the jetting is rich, what is the probability of a lean run in the mid range? I'm also running carb heat full time so how much does that richen the jetting?
For the rest of this winter I'm not going to play with the jetting but I do want to change the needles. Here are my options: 145/143.8/143.8 45 pilot 1.5turns 3.0 clip (but set at 2.5) down to 0F for 300-1700' (Where it's jetted now). What does that 1/2 clip position do in the big picture? Next option is 143.8/142.5/142.5 45 pilots 2.5 clip. This gets me into the 2.5 range on the tuning scale for the elevation increases I will see while riding but jetting is still rich.
The 2 blocks with hi-liter are what I'm torn between. I can't see myself riding below zero ever but I may be between 0 and 20 below 1700' and anybody's experience with jetting and wash/plugs when that happens would be great advice.
02 MM700 Stock Pipe, MBRP Can and vForce reeds.
Thanks! Enjoying the blizzard in New England right now
I had set my needles at 3.5 the first year that I owned the sled and run it that way ever since, the plugs had good burn on the ground but the color was always on the black side. I did that out of worry with ethanol fuel and was always running 91 ethanol out of safety since I didn't trust 89 with ethanol in it to be close enough to Yamaha's 88 octane spec.
I have moved now and can get 91 ethanol free from a station that's trail side. It's my fuel source of choice now and I'm not too worried about low turnover. I want to set my needles back but am wondering where to go. Torn between 3 and 2.5. The elevation at the new house is 675' and anywhere I go to ride is just going to be an increase in elevation. I'm realistically in between the 300-1700 and 1700-3300 foot tuning columns for the MM700 when I ride. Most rides will start at or just below 1700' and end the day above it, but never going over 3300' From 20F up I'm at 2.5 on the needle through both columns, I don't need to be at 3 until I'm below 0F in the 300-1700 column.
I have read that all sleds, not just yamaha are jetted rich from the factory which I completely understand. How does this tolerance carry over with the jet needles? If I end up starting the day between 0F and 20F where it calls to be jetted at 3.0 and I'm at 2.5 even though the jetting is rich, what is the probability of a lean run in the mid range? I'm also running carb heat full time so how much does that richen the jetting?
For the rest of this winter I'm not going to play with the jetting but I do want to change the needles. Here are my options: 145/143.8/143.8 45 pilot 1.5turns 3.0 clip (but set at 2.5) down to 0F for 300-1700' (Where it's jetted now). What does that 1/2 clip position do in the big picture? Next option is 143.8/142.5/142.5 45 pilots 2.5 clip. This gets me into the 2.5 range on the tuning scale for the elevation increases I will see while riding but jetting is still rich.
The 2 blocks with hi-liter are what I'm torn between. I can't see myself riding below zero ever but I may be between 0 and 20 below 1700' and anybody's experience with jetting and wash/plugs when that happens would be great advice.
02 MM700 Stock Pipe, MBRP Can and vForce reeds.
Thanks! Enjoying the blizzard in New England right now
Backwoods M Max
New member
Nobody?
Things must be getting slow around here.
Things must be getting slow around here.
Cheaper to foul some plugs then smoke the motor. Start rich and reassess. Just my thoughts.