Aftershock Throttle Problems

[wilxayboi]

hey guys i was wondering if i could get any help with my losi aftershock?

I'm trying to tune it up from factory settings which are:

HSN: 3 turns out from bottom
LSN: 3 turns out from bottom

I'm also using that flow diagram that is posted on the General Talk forum by the way (it comes in very handy).

I've got it so the engine can keep an idle speed and also that it doesn't die when i full throttle it. BUT, when i come to let the throttle off, the RPM dies down as normal but as it starts to get to idle speed, the pitch of the engine changes. It goes from being that classic 2 stroke noise that we all love to hear, to being a quite high pitched humming noise. AND it wont stop when i apply the brake.

Please help me out because not only is this VERy anoying but also i can only stop the truck from moving by applying the brakes which i shouldnt have to do when I'm not accelerating.

Look forward to the help guys!!!!
Thanks:bow:

 

[Cupooterluvr]

Your idle sounds like it is too high. Check the gap to make sure it is 1mm. If it is then your LSN may be too lean. Richen it 1/8 turn and retry.

 

[wilxayboi]

No the idle is fine. i will try the LSN but the noise changes sooooo much that i dont think its the idle because it will be idleing then sometimes the slightest touch of the throttle will make it humm like a bee.

Tis Very Strange....

 

[Cupooterluvr]

You might also have an air leak.

Obviously describing sounds can only go so far. I'm thinking that if you could get us some video with sound then we can help better. I might know what you're talking about though.

Like when it stops, after a couple seconds it idles up and starts sputtering? And kinda wants to jump forward? If so then it's an air leak. I've got one that I can't track down on my T-Maxx and it doesn't bother me. It only happens every once in a while.

 

[wilxayboi]

no it will idle all day if you let it and it wont try to jump forward. i will work on getting you a video clip so you can see what i mean about 'humm' it will only humm if you accelerate fully then let the trigger go.

I will report back either tomorrow or the day after with a video clip and hopefully hit the nail on the head.

 

[olds97_lss]

Sounds like your a bit lean on the LSN. My AS engine did that too when I went too far. For that matter, my buddies 427 and SH28 both also do it when you go too lean on the needles. It makes for a wiggy idle down that sometimes seems to stick at an odd sound and much higher than idle RPM.

That being said, my stock AS engine had air leaks all over. Even the fuel filter leaked all over due to improper installation of the o-ring at the factory. I sealed the carb neck, carb cinch bolt and backplate. I also took the o-ring off the fuel filter, cleaned the threads with DA and put a smear of RTV all over the threads and put it back together.

The tune was much more stable after all that, but would do the weird idle drop thing when tuned too lean on the LSN.

 

[wilxayboi]

thats axactly what it is!! thankyou so much i will try the low speed needle and check for air leaks. thanks very much!!!!