Tuning Help

[SilentWov]

I new to tuning, so let me see if I'm thinking about tuning in a correct way:

As I understand it, the low-end needle is set for idleling and quick responsiveness?

And the high-end needle goal is to set it for a perfect fuel-air mixture but slightly rich?

Is this about right? Any comments, thoughts, links would be appreciated to help me better understand the mosquito.

 

[SkyMaxx]

Idle set screw is for setting the idle or the gap in the carb when the carb is at the closed position.

LSN is for setting fuel mixture or metering fuel during the engines low rpm stages (idle and acceleration).

HSN is for setting fuel to air mixture on the top side. Keeps the engine running and helps with throttle changes once the vehicle is moving.

As for settings, that will vary from location to location and weather to weather. I run my HSN on the rich side, but performance is best had with a lean setting.

 

[SilentWov]

Ah ha! I seen a guy tuning the LSN by revving the motor at low rpm. You want crisp responsiveness there right?

So how is the best way to tune the HSN? Rev to WOT, or judge by the way it accelerates on the ground? You're looking for a healthy sound and smoke I assume. How do you figure where the HSN should be?

 

[Nitro_Keebler]

Originally posted by SilentWov
Ah ha! I seen a guy tuning the LSN by revving the motor at low rpm. You want crisp responsiveness there right?

So how is the best way to tune the HSN? Rev to WOT, or judge by the way it accelerates on the ground? You're looking for a healthy sound and smoke I assume. How do you figure where the HSN should be?

You said it, check the car on the ground... and look for good smoke and responsiveness You sound like you know what to do, just afraid to apply it.

Plus get a temp gun to check after wot test.

 

[olds97_lss]

You also tune the low speed by keeping track of how long you let it sit at idle. You want to run somewhat rich on both the high and low to preserve engine life. If you let the vehicle set for 5-10 seconds, then gun it, it should take off with minimal or no hesitation. If you let it set idleing for 30seconds to a minute, it should load up on you.

The high side should allow you to open it up and run through the rpm's cleanly without sputtering or overheating. If you get a real high pitch wine, but low power, your running it to lean. If you get a gurgling, your to rich.

 

[SilentWov]

My first time out at the track, a veteran helped me "tune" my engine. It ran very well, but very hot. We're talking 320. He made adjustments in 1/8 turns on the HSN to richen it. It seemed the problem I had was: I was running out of gas in the 5-minute race and running hot, or it was running so hot that the power dropped off bad.

The conflict seemed a no-win. To richen/cool it, I would only run out of gas faster?

My second time out at the track, I just figured hell, I need to learn the way of the mosquito myself, so I de-tuned it, started with the needles a couple turns out each. I purposely tuned the LS a little rich, but torque-y, and the HS on the rich side as well, but clean sounding. It sat on the line for 30 seconds, and when I gassed it, it died. My buddy was right there, so he got it started right back up. To my surprise I qualified second, did an extra lap, with fuel remaining, and at a temp of 280.

I was thinking it was too rich to build up and stall like that? Or is that about right, and I just have to blip the throttle every so often?

Another question is: Does the motor use less fuel at lower temperatures? ie more efficient?

I appreciate the thoughts and comments, theres so many other areas of the car to work on, I just need to figure out the motor first.