How do i reset HSN & LSN?

Welcome to RCTalk

Come join other RC enthusiasts! You'll be able to discuss, share and private message with other members of our community.


RCNT Rookie
Hi, I'm trying to retune my Mach 427 nitro engine. According to the manual says I should turn each needle 2.5 turns out. Does this mean 2.5 full turns (i.e from 12'oclock to 12'oclock)? Because when I tried this my car died every time I gave it throttle due to the fact that it's running too rich. Where'd i go wrong?
Thank you


RCNT Rookie
It means you screw both screws in until the bottom out, then back them out 2 full turns and 1/2 turn.

What's in the book is usually "break in" settings which are typically on the rich side.

What I read in the manual was 4 turns for the HSN and 2 for the LSN:

That's funny, the instruction manual is different for the Mach 427 and the Losi 427. I actually tried 4 and 2 and couldn't even keep it started. I'll try doing 2.25 and 2 tomorrow and see how it goes.


Dekalb, IL
RC Driving Style
Pretty sure the "losi" 427 and "dynamite" 427 are both dynamite. There were a couple versions though, gold head and grey head. I think the grey head ran a higher flowing carb. Maybe the gold was "dynamite" and the grey was "Losi".

Oddly, can't find the carb part number for the gold version, only carb parts. The opposite with the Losi/grey one. I can find the entire carb, but not the parts. lol

The grey one's manual is 2.5 turns for both.

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Thread starter Similar threads Forum Replies Date
R Is it possible to Reset a Spektrum? Electronics 1
JaeJae Reset to Factory Settings?? Traxxas T-Maxx 7
marauder Losi Mini-LST2 - Reset ESC now have no reverse?! Mini & Micro RC 8
ZANDOR 3PK reset Electronics 3
P Master Reset Electronics 2
X How to reset the carburator needles in a Dirt Demon Monster Trucks 2
JohnSampson Nitro engine HSN Nitro RC 5
jwilson idle screw and hsn tuning Chassis & Drivetrain 12
REVO-5309 HSN seal loose Nitro RC 12
nazUK HSN Holder keeps on going loose Nitro RC 7
M Revo 3.3 tuning help - HSN 4.5 out and 265F Traxxas Revo 17
ckeast420 Please help! Lost washer off hsn lrp 30 Chassis & Drivetrain 1
P Dynamite Mach. 26 hsn Loose Chassis & Drivetrain 4
P hsn screw Nitro RC 4
Jonnybagstrx hsn 6 turns out Traxxas T-Maxx 24
A (Noob question) Throttle Trim - Does it override LSN or HSN? Nitro RC 21
S 2.5 T-Maxx HSN vibrates out of adjustment Traxxas T-Maxx 4
C 3.3 hsn 7-8 turns out just to run WTF? Traxxas T-Maxx 5
Metalhead Matt Self adjusting hsn Traxxas T-Maxx 2
D Any advice for a stripped hsn/ fuel line connection Traxxas T-Maxx 12
blckrevo33 cleaning hsn needles? Traxxas Revo 2
D Uhm, which way to turn the HSN and LSN? :S Chassis & Drivetrain 4
T HSN more than 4 turns out Traxxas Revo 3
A LRP Z.28R Spec 3 - HSN & LSN Counts Chassis & Drivetrain 3
M Overheating 3.3 with HSN almost 5 turns out Traxxas T-Maxx 6
C Stripped hsn housing fix? Nitro RC 19
A Idling,HSN,LSN Is it good togo? Nitro RC 7
N hsn issue Nitro RC 2
D TRX 3.3 T-Maxx Factory Idle Setting? Not LSN or HSN but the idle screw Traxxas T-Maxx 4
D Problems after replacing HSN Nitro RC 13
X Help please! Stock setting for a hyper 7 .21 lsn and hsn Buggy and Truggy 4
I When breaking-in engine HSN or LSN is adjusted first? HPI Savage 3
W High temp problems even with HSN at 5 turns out!! Nitro RC 2
L Your favorite way to tune HSN? Chassis & Drivetrain 13
E HSN question Nitro RC 1
G Why do we need 2 needles (LSN and HSN)? Chassis & Drivetrain 17
P Hpi Evo 3 Hsn On-road and Rally Cars 9
1 4.6 engine HSN needle settings HPI Savage 3
D Loose carb HSN Buggy and Truggy 8
W Hsn Traxxas T-Maxx 12
B os18 tm HSN Traxxas Revo 2
D Cracked Carb Body HSN Traxxas Revo 3
S TRX 2.5 HSN setting??? Traxxas T-Maxx 1
S hsn setting for break in HPI Savage 8
K Ambient temperature effects on the HSN mixture setting Nitro RC 5
I picco hsn what not to do HPI Savage 6
R HSN setting? HPI Savage 6
J Idle Screw VS LSN Nitro RC 21
J Video example of LSN extremes: Rich vs Lean Nitro RC 1
IdriveSlideways LSN wet? Nitro RC 16
Similar threads