Spark plug question

[gary55]

tried the top, this worked wonders. i have another nt carb that has a 5 slot slide, should i change the carb or could i just use the slide from one carb to another?

Look at the needles. If they appear to be the same length and taper it should be fine. Nothing shows results like a experiment so if it gets too lean you can always change back. If it's too lean it will balk when you snap the throttle wide open. The slide in the speed carb is slightly larger and won't work in the NT.

 

[UDAHOE24]

Look at the needles. If they appear to be the same length and taper it should be fine. Nothing shows results like a ezperiment so if it gets too lean you can always change back. If it's too lean it will balk when you snap the throttle wide open. The slide in the speed carb is slightly larger and won't work in the NT.

experiment it is then. ill have to try this later. ill write back what happens

 

[UDAHOE24]

tried the different pin but it was smaller than the original. i put my carb back together and it must have gotten som dirt in it or something becuse it lost the power again.

 

[LewieBike]

tried the different pin but it was smaller than the original. i put my carb back together and it must have gotten som dirt in it or something becuse it lost the power again.

Those 'pins' are metering needles, they are supposedly used to meter the gasoline precisely into the engine at part throttle openings, but these carbs are sorta imprecise to be honest.

You said you looked at the other one, and it's 'smaller'? In what way? Did you hold them side by side? Was one shorter? Was one smaller in diameter?

The differences would be so slight that it should take a digital vernier caliper to measure the differences. Quality motorcycle carbs running metering needles will have such fine differences in their needles, that they have to be numbered to tell them apart. Generally judging metering needles is not something you can tell just by a calibrated mark 1 eyeball.

If the needle you traded to was smaller, and if the engine ran crappier, it's a good chance it's way too rich again in the mid throttle range. I'd go back to the needle that ran better first and work from it's best C-clip position.

 

[UDAHOE24]

Those 'pins' are metering needles, they are supposedly used to meter the gasoline precisely into the engine at part throttle openings, but these carbs are sorta imprecise to be honest.

You said you looked at the other one, and it's 'smaller'? In what way? Did you hold them side by side? Was one shorter? Was one smaller in diameter?

The differences would be so slight that it should take a digital vernier caliper to measure the differences. Quality motorcycle carbs running metering needles will have such fine differences in their needles, that they have to be numbered to tell them apart. Generally judging metering needles is not something you can tell just by a calibrated mark 1 eyeball.

If the needle you traded to was smaller, and if the engine ran crappier, it's a good chance it's way too rich again in the mid throttle range. I'd go back to the needle that ran better first and work from it's best C-clip position.

I held them side by side, and the one on my bike is very noticably bigger than my spare carbs pin. The smaller one also has the 5 notches for the clip where as the bigger carb only has 4 notches.

Also I've neglected to clean the carb or do anything with it since my last post. So I don't have any updates on it, as far as I know she's backfiring every now and again, but she still moves better than she did before I played with the clip in the first place

 

[LewieBike]

An optimally tuned engine can lose power from poor fuel mixture changes in two ways, it can start running really rich, and running too lean.

Running too lean can kill your engine, running too rich just makes your spark plug foul and coke up. Better to err on the side of too rich.

Like I was saying you didn't describe the differences between the two needles except to say that one is noticeably bigger..? In what way?