hi houston,
just wondering why offroad .21engines usually use a much hotter plug than onroad .21engines?

i've seen people using os p3 for their offroad engines but when it comes to onroad engines they'll use a much colder plug like nova#7. both using 25% nitro, air temp about 77F and humidity about 70%.

also, which is more damaging? over lean HSN or over lean LSN?

the only thing i can really think of about the onroad plug thing is the way the throttle is applied , the weight of the car and the fact that they are always towards the upper revs of the engine . off road cars are definitely easier to tune with the hotter plug , our offroad engines IMO have a much higher torque load that they transfer to the engine so they like to use a hotter plug to give an advanced timing to the engine .



over lean hsn because thats where your engine is revving and needs more oil :nod:

not saying that a lean bog off the bottom is a good thing but its not just caused from a lean lsn . usually high temps or wrong pipe ;)

thankyou for yr reply houston. :D

however, what i'm trying to ask about the engine lean issue is that; what damages will happen to the engine if:

you're running it too lean on the
1) LSN, 2) HSN

by the way, how will the tune be affected if there's a change of plug? example from #6 to #5 or from #5 to #6?

what are perfect running temps for a OS V-spec?

There's no such thing as the perfect temp for any engine? Throw your temp gun into the bottom of your pit box and only use it for running in!... Learn to tune by power, sound and smoke. It's a much more accurate way of getting the best perfomance and longevity out of your engines.

google RON PARIS and you'll find the best tips for tuning nitro engines!

low speed usually equates to poor low end performance with possible temp spikes and a very high idling that pushes you through the corner .

high speed usually equates to an out of balance feel when running and and much less engine life due to low lubrication flow on throttle .

:blush:

or just look at post #1 ;):weird:

so it's more damaging to an engine with a lean HSN than a lean LSN...:sweat:

thats what i said in this post ;)http://www.rctech.net/forum/6090701-post77.html

Hahaha, i forgot what thread i was in! :)

newbie
 

hi guys

ive just got my frist buggy and me knowing nothing about tuning i'd thought ill ask what will happen if the car is

lean on bottom and what will the car do???
rich on bottom " "
lean on top " "
rich on top " "

or what should i look for.

as i really dont wanna stuff my motor


cheers

i bought a losi 8ight 2.0 rtr buggy when they first came out and i have been racing it for a month and half. i still have the stock losi 350 engine in it and has great power and seems to run great.

my problem is when it flames out or runs out of fuel, it is nealy impossible to get it to restart until it sits for a while. it temps at about 250 when its 90 outside. i'm wondering if the metal carb could be causing vapor lock because it does not seem to be insulated from the block. thanks for the help.

speed freak your too lean on bottom when you flame out hot and its hard to start there is not enough fuel richen your l/s an hour or two and you will find it better

rich will burble lean will hesitate then quit engine should idle smoothly and return to idle after throttle snap. If engine continues to rev after idle snap it is too lean richen the l/s needle if engine bogs and burbles after snap it is too rich on bottom. If engine idles but won't rev has lots of smoke and burbles it is rich on high speed needle if hesitates and revs to a screaming pich it is lean may even stall just quick pointers I recoomend getting someone with experience to help you at local track or hobby shop.

after a high speed pass, my engine will idle slightly higher; however if i blip the throttle, it'll return to normal idle.
if i don't blip my throttle, it'll return to normal idle after about 5s.
my guess is the LSN still abit lean? :weird: