Mikuni TMX 35
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bryansmudge
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Can one of these adjustable powerjets available nowadays be fitted to a Mikuni TMX 35, I realise that they are supposed to allow the reduction in the main Jet, but I was thinking would this also richen up the mid range leaning off in these carbs? Any advice from the carb Guru's mucho appreciated.
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Knowledge
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Bryan,
It is worth asking the question, because I am aware of these powerjets being used for this very reason. One of the off the shelf kits (I forget which; there are so many) has a habit of running dangerously lean when coming off the throttle at high engine speed, causing failure. A correctly set-up powerjet can fix the problem.
I have not heard of one of the PJ kits being fitted to a Mikuni TMX35, but if it can be physically fitted I suspect it would work.
Perhaps a grown-up with a bit of experience may come along and answer the question a little more fully.
It is worth asking the question, because I am aware of these powerjets being used for this very reason. One of the off the shelf kits (I forget which; there are so many) has a habit of running dangerously lean when coming off the throttle at high engine speed, causing failure. A correctly set-up powerjet can fix the problem.
I have not heard of one of the PJ kits being fitted to a Mikuni TMX35, but if it can be physically fitted I suspect it would work.
Perhaps a grown-up with a bit of experience may come along and answer the question a little more fully.
Martin
Interesting point......
I suppose if there is room to fit it on the body of the carb....yes.
However if it is leaning out in the mid already you would probably have to set the power jet to deliver more fuel at this point but then it will deliver more than you need at WOT because it cuts in at just under half but delivers more fuel as you go towards wide open throttle so you will probably end up chasing your tail.
If you then lower the main you will still lean out the mid range slightly again so more fuel will be needed from the power jet which will then again deliver too much at wide open throttle......Hope that sort of makes sense....
Could be wrong but that's how I would see it.
When you come off wide open throttle to shut off and have overheating issues your pilot/mid is too lean. When you come off wide open throttle to cruise in the mid (big danger area with our 2 strokes) and it overheats, your needle/atomiser is too lean. That is why I am personally not a fan of the fixed atomiser ilk of carbs.
Because we all mostly run modified pipes (ooooooeer missus)......mostly expansions...we have a defined power band when the engine is demanding much more fuel. Out of this band , if the scooter is jetted correctly, it will probably miss, splutter etc
So many scoots have seized due to people trying to clean this "off power" area up by down jetting and then when in the power band the jets are too small to deliver the fuel required.
This is where the power jet comes in. By leaning off the main, it has a leaning effect in the mid range too which then cleans up the carburation when off the power. The power jet then supplements the leaning of the main as the revs rise, kicking in from about half throttle to maximum fuel delivery at full throttle.
I suppose if there is room to fit it on the body of the carb....yes.
However if it is leaning out in the mid already you would probably have to set the power jet to deliver more fuel at this point but then it will deliver more than you need at WOT because it cuts in at just under half but delivers more fuel as you go towards wide open throttle so you will probably end up chasing your tail.
If you then lower the main you will still lean out the mid range slightly again so more fuel will be needed from the power jet which will then again deliver too much at wide open throttle......Hope that sort of makes sense....
Could be wrong but that's how I would see it.
When you come off wide open throttle to shut off and have overheating issues your pilot/mid is too lean. When you come off wide open throttle to cruise in the mid (big danger area with our 2 strokes) and it overheats, your needle/atomiser is too lean. That is why I am personally not a fan of the fixed atomiser ilk of carbs.
Because we all mostly run modified pipes (ooooooeer missus)......mostly expansions...we have a defined power band when the engine is demanding much more fuel. Out of this band , if the scooter is jetted correctly, it will probably miss, splutter etc
So many scoots have seized due to people trying to clean this "off power" area up by down jetting and then when in the power band the jets are too small to deliver the fuel required.
This is where the power jet comes in. By leaning off the main, it has a leaning effect in the mid range too which then cleans up the carburation when off the power. The power jet then supplements the leaning of the main as the revs rise, kicking in from about half throttle to maximum fuel delivery at full throttle.