dclintonh

what does it adjust?
ive never adj it on either one of my buggys, and i was wondering what it improves? i really should probly know by now but ive just thought that it was suppost to be flush.
and i did a search and didnt see what i was looking for.
what symtoms i would look for to adj which way.


thanks for all you guys help.

mozzzy_2000

Ok I'll to resist asking but how the heck have you been able to keep your engines properly in tune with knowing what the LSN does? Sorry to take it back a few notches but have you got a grasp of the other needes such as the HSN, the idle adjustment screw and the MSN(if it has one)?

Anyway the basics are that the HSN controls maximum power & top speed; the LSN controls the idle mixture and the immediate throttle response whilst the idle adj, screw controls the idle level. Clockwise leans the needles out whilst anti-clockwise richens the needles.
You tune the HSN first then the LSN & idle last. Once you have tuned in the HSN for satisfactory top speed, the LSN is dialled in for idle mixure and throttle response. Ideally when properly in tune, the engine should accelerate smoothly from the instant you apply the throttle.
A good method to tell whether your LSN is in tune is the pinch test. Run the car up to speed, bring it in and pinch the fuel line about 1" from the engine inlet nipple until the engine cuts out. If the engine's revs increased dramatically for some seconds before cutting out then the LSN is too rich; If the engine's cuts out immediately then its too lean. What it should do is that the RPMs should increase a little before the engine cuts out after a few seconds.
Another similar method is by listening to the engine and how it settles after a WOT blip. Bring it up to running temp and with it off the ground give it a good blip of the throttle. Listen to how the engine settles and resumes idling. If the RPMs of the idle goes higher or remains high and the engine does not settle back down its an indication the LSN is too lean. If the RPMs dip and go low and bogs the engine down eventually cutting out, then its likely the LSN is too rich. Ideally after a WOT blip, the engine should settle into a normal idle until it eventually bods down after about 20 secs before cutting out. Of course this is not as easy as it sounds because it can be hard to tell whether a lean setting is raising the idle or if infact its just the idle adj. screw that needs to be turned down a smidge. The more you do it, the better you become at learning the different aspects of tuning.

rclynx

Are you sure those rules apply mozzzy after all you guys run your cars up side down LOL that was some good advise / I just had to say welcome back to Mozzzy from the land down under. [:-]

AllAboutFunHobbies

Wow, what did he say a WOT a BLIP, oh I'm so confused[sm=spinnyeyes.gif] Just yankin your chain. I always started my tuning with the idle, LSN, HSN in that order. Guess it really doesn't matter as long as you get the end result.

dclintonh

thanks guys, that explains why my hurricane bogs out so bad, goes great on top end but bogs bad on initial responce and it keeps dieing when i give it gas at start up. it will start great, but die when i give it gas.

but does that sound like its too rich or to lean?

thanks

MiniCwik

Too rich IMO, but I am no expert.

I recently richened mine up (3/4 of a turn CCW to almost flush) because it was too lean on the LSN (I was 1 full turn CW in from flush), which I could hear while letting off the accelerator or when taking off. It would sound like it was not getting fuel (cutting out).

It may be hard to tell between bogging out and cutting out.

ehroof

its hard to say, it may be loading with fuel at idle so it bogs down if it is too rich, it may not have enough fuel so it cuts out from an idle, i would suggest richining the lsn a little at a time and see if it helps, if not try start leaning it, i would think its probably too lean since you say it starts easy, when they are too rich it usually floods out. make sure you run the car a minute to let the adjustments start to work. before you turn the needles more

MiniCwik

See, told you I was no expert

ehroof is right, make adjustments to see if it gets better on the LSN ... drive it a little and see if it improves, if not adjust the other way giving it time to adjust.