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-   -   "the tuning bible" (https://www.rctech.net/forum/onroad-nitro-engine-zone/295490-tuning-bible.html)

houston 05-08-2010 09:39 PM


Originally Posted by mbx5rcr34 (Post 7379694)
guys i need your input here we went for practice yesterday & everything was fine new clutch shoe,spring & cleaned filter , except the jx motor flame-out (half-tank) ,so i tried to richen the top (hsn) & fill it up again after some passes same thing when it rich to half-tank it will flame-out ,i tried new p3 plug same thing,if not half-tank it will flame-out on 1/4 mark

put a new tank in it ;)

go to the ebmods js thread , there are a number of experts on that engine in there

mbx5rcr34 05-08-2010 09:58 PM

i just change the tank recently ,i would say 10 tanks already

shauncarman 05-09-2010 12:13 AM

Very Helpful:tire:

triple7s 05-09-2010 06:52 PM

Tuning help
 
I just chased a tune all day. I put a new carb on a good running OS v-spec, old one's slide was sticking. It ran great on the starter box, started right up, idled good, good power etc. until it was put on the track. At best it would run great on the straight, i'd coast through the sweeper, then when I got back on it, it gurgled like it was loading up. Re-tuned and it would bog and try to die at half throttle, a couple times it backfired (again it was perfect on the bench). Tried numerous time, same results.

It seemed like it only acted up under load. Other suggested an air leak, it didn't seem like an air leak to me but I was willing to try anything, so I changed fuel lines, tightened carb, pipe etc.

I thought maybe a clutch problem but just pulled it apart and it seems good. Is this maybe a mechanical problem seeing it only happens with the cars wheels on the track?
Any ideas??? :confused:

houston 05-11-2010 04:07 PM


Originally Posted by triple7s (Post 7383105)
I just chased a tune all day. I put a new carb on a good running OS v-spec, old one's slide was sticking. It ran great on the starter box, started right up, idled good, good power etc. until it was put on the track. At best it would run great on the straight, i'd coast through the sweeper, then when I got back on it, it gurgled like it was loading up. Re-tuned and it would bog and try to die at half throttle, a couple times it backfired (again it was perfect on the bench). Tried numerous time, same results.

It seemed like it only acted up under load. Other suggested an air leak, it didn't seem like an air leak to me but I was willing to try anything, so I changed fuel lines, tightened carb, pipe etc.

I thought maybe a clutch problem but just pulled it apart and it seems good. Is this maybe a mechanical problem seeing it only happens with the cars wheels on the track?
Any ideas??? :confused:

make sure you have the proper shimming under the head ;)

TC3ElectricGuy 05-13-2010 04:01 AM

quick question..

i'm running in an engine axe cobra x1 evo .21

i've done about 2L through the engine now and it's starting to get some serious top end speed.

when tuning this engine i have found myself having to richen the mixture to get a better top end without lean bog (which i have experienced when running this engine in). so i richened the HSN by upto 1/4 turn..
does this seam right with a new engine? is this just the engine wearing in and finding new RPM?

also. when applying open throttle, backing off, then applying open throttle the engine would surge slightly on the 2nd take of... once again, is this just a result of a too rich mixture... both HSN and LSN, and/or the engine wearing in?

at all times the engine has blown blue smoke. with the spit test . spit evaporated after about 6 - 8 secs.

DaveG28 05-15-2010 02:45 PM

Hi guys,

i'm a bit of an amateur and have accidently adjusted my LSN on my OS speed while adjusting the throttle ballstud position!

As it runs now it's fine once it's off and running, it doesn't stall quickly when sat idling but under initial acceleration it sits for 1-2 seconds before clearing out and accelerating with initially a lot of blue smoke. The HSN is definitely bob on so it is only the LSN that needs adjusting, does it sound too rich or too lean?

tkhoo 05-16-2010 05:32 AM


Originally Posted by DaveG28 (Post 7409085)
Hi guys,

i'm a bit of an amateur and have accidently adjusted my LSN on my OS speed while adjusting the throttle ballstud position!

As it runs now it's fine once it's off and running, it doesn't stall quickly when sat idling but under initial acceleration it sits for 1-2 seconds before clearing out and accelerating with initially a lot of blue smoke. The HSN is definitely bob on so it is only the LSN that needs adjusting, does it sound too rich or too lean?

too rich on your LSN. Lean it little by little.

Cappy 05-16-2010 06:37 AM


Originally Posted by DaveG28 (Post 7409085)
Hi guys,

i'm a bit of an amateur and have accidently adjusted my LSN on my OS speed while adjusting the throttle ballstud position!

As it runs now it's fine once it's off and running, it doesn't stall quickly when sat idling but under initial acceleration it sits for 1-2 seconds before clearing out and accelerating with initially a lot of blue smoke. The HSN is definitely bob on so it is only the LSN that needs adjusting, does it sound too rich or too lean?


Try the pinch test :nod:

deadmancourt 05-17-2010 03:08 PM

i have been reading this whole thread to try to weed out the good and bad ideas and have tried them all.....but the 1 i like best is: GET THE MOTOR TO OPERATING TEMP,THEN DO A COUPLE HIGH SPEED RUNS AND LEAN THE HIGH SPEED NEEDLE LITTLE BY LITTLE TILL IT BOGS @ HIGH SPEED THAN RICHEN THE HSN ABOUT 1-2 HOURS DEPENDING ON YOUR OWN LIKEING.....THEN LEAN THE LOW SPEED NEEDLE LITTLE BY LITTLE TILL IT BOGS WHEN THROTTLE IS QUICKLY APPLIED,THEN RICHEN IT ABOUT 1-2 HOURS DEPENDING ON YOUR LIKEING AGAIN....IF YOUR MOTOR IS IDLEING ALITTLE HIGH JUST BACK OFF ON THE IDLE SCREW TILL IT IDLES AND THE CLUTCH IS NOT ENGAGING....AFTER THATS ALL DONE YOUR MOTOR WILL SCREAM! AND IDLE GREAT!:batman:

mbx5rcr34 05-21-2010 04:28 AM


Originally Posted by houston (Post 7379723)
put a new tank in it ;)

go to the ebmods js thread , there are a number of experts on that engine in there

........its for my ninja jx21 sorry for the incomplete details,anyway i just realized that i messed-up the MRN setting i just change the o-ring & its acting-up ,but i got it right this time ,so it will idle no-flame-out ............today i just noticed that theres some oil behind the flywheel ,i guess oil leak ,is this the time for replacement ??

maiden723 05-23-2010 09:11 AM

losi mach 427 tuning
 
i need help i cant get this engine tuned right all its broken in just need help tuning it any help would be nice it dies after about 10 seconds of idling and wen i hit the throttle it just dies please help

i have had my aftershock for four years and still dont know how to tune please help

tkhoo 05-24-2010 08:29 AM


Originally Posted by maiden723 (Post 7443680)
i need help i cant get this engine tuned right all its broken in just need help tuning it any help would be nice it dies after about 10 seconds of idling and wen i hit the throttle it just dies please help

i have had my aftershock for four years and still dont know how to tune please help

too rich on your LSN.

maiden723 05-24-2010 05:38 PM


Originally Posted by tkhoo (Post 7447987)
too rich on your LSN.

ok thanks

tharris1959 05-26-2010 05:50 PM


Originally Posted by TC3ElectricGuy (Post 7399695)
quick question..

i'm running in an engine axe cobra x1 evo .21

i've done about 2L through the engine now and it's starting to get some serious top end speed.

when tuning this engine i have found myself having to richen the mixture to get a better top end without lean bog (which i have experienced when running this engine in). so i richened the HSN by upto 1/4 turn..
does this seam right with a new engine? is this just the engine wearing in and finding new RPM?

also. when applying open throttle, backing off, then applying open throttle the engine would surge slightly on the 2nd take of... once again, is this just a result of a too rich mixture... both HSN and LSN, and/or the engine wearing in?

at all times the engine has blown blue smoke. with the spit test . spit evaporated after about 6 - 8 secs.

Are you using the cold plug they recommend? I went to a hotter plug, the tune was more consistent


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