Wierd high speed needle cover, can't adjust it
07-25-2008, 07:54 PM
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Wierd high speed needle cover, can't adjust it
I have a ZAMA C1U carb that has a long smooth "rod" in the place of the high speed needle adjustment. I have heard of these but no experience with them. Can it be removed to access a needle? Replaced with a needle? Tried lightly to turn it but nothing happened. Didn't do any more. I need to remove it because the carb is plugged up solid and not getting fuel correctly.
07-26-2008, 07:40 AM
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RE: Wierd high speed needle cover, can't adjust it
don't wasste your time on single needle carbs. Been there, spent too much time on it. We need both needles to adjust our engines well.
07-26-2008, 09:32 AM
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RE: Wierd high speed needle cover, can't adjust it
I know what you mean. Been there too. But I have an engine to repair for another person and figured this is as good a place as any for information. Maybe better. Get more opinions and variations compared to an OEM.
When will some one come out with a 3 needle carb so we can "really tweak" the mid range just the way we want it?
Has any one ever tried to add a third needle?
When will some one come out with a 3 needle carb so we can "really tweak" the mid range just the way we want it?
Has any one ever tried to add a third needle?
07-26-2008, 11:50 AM
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RE: Wierd high speed needle cover, can't adjust it
This new Walbro may be similar to what you have.
There is an aluminum ‘peg” where the h.s. needle would be.
The responses I had here,said that it may be best to
use it as parts.
There is an aluminum ‘peg” where the h.s. needle would be.
The responses I had here,said that it may be best to
use it as parts.
07-26-2008, 01:10 PM
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RE: Wierd high speed needle cover, can't adjust it
That looks like it. But I need to get the crap out of all the passages so it can be used again. Generally I take the needles out and spray cleaner thru the passages. Can't this time unless it can be removed. I may have another carb laying around that will work. If so then I can tear this thing apart, one way or another and learn just how it is built.
07-26-2008, 05:16 PM
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RE: Wierd high speed needle cover, can't adjust it
curiosity killed the cat? If so, I would be dead many times over. Go ahead and find out.
These carbs are set up for one particular engine, and are meant to have a very limited adjustment range ("CARB" California Air Resource Board is responsible for this). The main jet is fixed, but must do with whatever amount of fuel the single idle needle allows to pass through. For clean air, this single engine/carb combination approach is the way to go, and it serves all those well who never want to touch the needles. If however the prop changes, or altitude, or mean air moisture content, these carbs will be way off for most applications, except garden tools.
Since garden tools do pollute the air more than we modellers, That is what the authorities are after. Following the laws of sequential approach, our applications will be next down the line, so get your multineedle carbs while you still can.
These carbs are set up for one particular engine, and are meant to have a very limited adjustment range ("CARB" California Air Resource Board is responsible for this). The main jet is fixed, but must do with whatever amount of fuel the single idle needle allows to pass through. For clean air, this single engine/carb combination approach is the way to go, and it serves all those well who never want to touch the needles. If however the prop changes, or altitude, or mean air moisture content, these carbs will be way off for most applications, except garden tools.
Since garden tools do pollute the air more than we modellers, That is what the authorities are after. Following the laws of sequential approach, our applications will be next down the line, so get your multineedle carbs while you still can.
