Fine tuning cline regulator
04-07-2008, 03:05 PM
#1
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Fine tuning cline regulator
Hello
I have had very good experience with my cline regulator copupled with a moki 1.35 engine.
Nonetheless I am strugling to get the set running perfectly since it looks the engine is getting more fuel than needed in mid range.
I mean, I have closed idle adjustment and it goes just perfect, at full throttle I have closed needle valve and it runs fine, the problem I have is in mid range it sounds like flooded but if I close more the idle set , I get engine out in idle.
I am thinking about opening the regulator and lowering the lever a little bit, any suggestion about that?
Thanks in advance
Omar
I have had very good experience with my cline regulator copupled with a moki 1.35 engine.
Nonetheless I am strugling to get the set running perfectly since it looks the engine is getting more fuel than needed in mid range.
I mean, I have closed idle adjustment and it goes just perfect, at full throttle I have closed needle valve and it runs fine, the problem I have is in mid range it sounds like flooded but if I close more the idle set , I get engine out in idle.
I am thinking about opening the regulator and lowering the lever a little bit, any suggestion about that?
Thanks in advance
Omar
04-07-2008, 07:22 PM
#2
RE: Fine tuning cline regulator
Niche,
I have taken them apart, and tweaked them to set the height, because it was not flowing enough fuel. I might have deformed it a slight bit to begin with, since I replaced the viton tipped needle (10 years old). As logn as the rocker is flush with the inside of the case, that is the way it is intended to be. I am not sure that bending it to lesson the fuel flow will help you, it will probaly not supply enough at WOT then.
The Cline does not force fuel through the carb that it does not want.
The problem is the midrange in your carb, not the Cline.
I have taken them apart, and tweaked them to set the height, because it was not flowing enough fuel. I might have deformed it a slight bit to begin with, since I replaced the viton tipped needle (10 years old). As logn as the rocker is flush with the inside of the case, that is the way it is intended to be. I am not sure that bending it to lesson the fuel flow will help you, it will probaly not supply enough at WOT then.
The Cline does not force fuel through the carb that it does not want.
The problem is the midrange in your carb, not the Cline.
08-26-2008, 01:15 PM
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RE: Fine tuning cline regulator
I would have expected the exact opposite - Lean Run at midrange.
The reason I say that is that the carbs throttle barrel, low/mid needle have a flow profile that are meant for the recommended installation - muffler pressure. Muffler pressure is not a constant, variable from low to high through idle to WOT. Any regulator or pump exposes the carb to a more constant pressure (negative or positive) without any curve in the middle. If you bend the lever or change spring presssure so that it takes more diaphram pressure to lift the needle, this changes the SETPOINT of the regulator for suction pressure LOWER / LEANER over the entire range. Then you'll adjust the idle and main richer to compensate, thus giving you a relative lean DIP in the middle.
If that doesn't work, here is a version of an old drag racers trick. (This happens to be implemented on the latest YS110 carb version)
Reprofile the carb flow all by yourself. Not very hard to do. Take apart the barrel and file a notch on a strategic position in the top half of of the barrel so as it opens, you see this notch being exposed just off idle, and into midrange. The notch dissapears as it goes to WOT, or back to idle. (has to be off to the side a bit) What this does it expose the spray bar to a higher pressure (big hole above spray bar, smaller hole below) to lean midrange. The same thing can be done on the bottom part of the barrel to get richer midrange, (big hole under spray bar, small hole above) exposing the bar to more crancase suction. Position and shape of the hole is a big trick, you must use a sharpie to experiment with how the hole exposes and dissapears again in the throttle stroke. It can be notch, round, just about anything.
For the price of a barrel, its easy to go back.
I have yet to start my OS 1.20ax with the Cline. Maybe this week.
The reason I say that is that the carbs throttle barrel, low/mid needle have a flow profile that are meant for the recommended installation - muffler pressure. Muffler pressure is not a constant, variable from low to high through idle to WOT. Any regulator or pump exposes the carb to a more constant pressure (negative or positive) without any curve in the middle. If you bend the lever or change spring presssure so that it takes more diaphram pressure to lift the needle, this changes the SETPOINT of the regulator for suction pressure LOWER / LEANER over the entire range. Then you'll adjust the idle and main richer to compensate, thus giving you a relative lean DIP in the middle.
If that doesn't work, here is a version of an old drag racers trick. (This happens to be implemented on the latest YS110 carb version)
Reprofile the carb flow all by yourself. Not very hard to do. Take apart the barrel and file a notch on a strategic position in the top half of of the barrel so as it opens, you see this notch being exposed just off idle, and into midrange. The notch dissapears as it goes to WOT, or back to idle. (has to be off to the side a bit) What this does it expose the spray bar to a higher pressure (big hole above spray bar, smaller hole below) to lean midrange. The same thing can be done on the bottom part of the barrel to get richer midrange, (big hole under spray bar, small hole above) exposing the bar to more crancase suction. Position and shape of the hole is a big trick, you must use a sharpie to experiment with how the hole exposes and dissapears again in the throttle stroke. It can be notch, round, just about anything.
For the price of a barrel, its easy to go back.
I have yet to start my OS 1.20ax with the Cline. Maybe this week.
