ckblood05

iTrader: (15)

ok, im running the 3.3 in my t maxx. i keep reading and seeing different times for the pinch test. i hear when you pinch the fuel line, you want it to rev for 2-3 seconds then cut off. then i hear between 4-5, and 7 seconds. whats is the correct time for my 3.3?

ScottyM

iTrader: (27)

From my experience when the low speed is set correctly and you pinch the fuel line it takes almost, but not quite 3 seconds before engine starts to rev. If it is reving as soon as you pinch it is about 3 hours too Lean.. If it takes longer then 3seconds to rev then it is about, how ever many seconds it takes to rev over 3seconds, that many hours to rich on LSN..

Keep in mind these are only general rules, and no where near exact.. Good acceleration is the #1 thing to go by.. Always tune an engine at operating temp (around or above 200*), and if it starts to lean bog, Richen the engine immediately and turn it off with piston at BDC. After 10 minutes of cooling restart and retune..

I hope this helps..

shanem121

iTrader: (10)

Thats always how i have done it. Never has failed me.

ckblood05

iTrader: (15)

ok, because after about 2 seconds it starts to rev, then between 1-2 seconds after it quits. so im close. yea, i let the motor get warmed up, and make some runs then bring it in and pinch the line. it has good acceleration. sometimes if im at a dead stop, then gun it, it makes like a sputter sound then takes off. but if im rolling or moving a bit then gun it it takes off. like i'll stop, sit there a second or two, then pull the trigger all the way. it will sputter, then once it gets going, it pulls the front wheels off the ground. so roughly 4 seconds fromt the time i pinch the line it should shut off?

ScottyM

iTrader: (27)

I would say closer to 5 or 6 before it actually dies.. Fromt he discription it sound a touch lean still. Richen the LSN an hour and see how it acts then.. I fit is still hesitant on take off, check to make sure your clutch isn't engaging too soon.. As this can cause a lean bog senerio as well, even though it isn't actually lean bogging..

It sounds like you are very close. Just barely move that LSN and see what you end up with..

ckblood05

iTrader: (15)

ok, i will give it a try. yea, i just replaced the stock traxxas clutch shoes with the mip ones. how do i know if my clutch is engaging to soon?

ckblood05

iTrader: (15)

ok, im running my t maxx in my inclosed garage because it is like 60 instead of 41 outside. but im trying to get my idle dialed in. when i do the pinch test, it takes about exactly 4 seconds to shut off. but it seems rich. i mean if im ideling then gun it, it bogs. but before i turned the lasn richer, it took off good. but my temps were getting in the 270's. i think my idel screw is broke. its like no matter how i turn it, it seems not to really do anything sometimes.

ScottyM

iTrader: (27)

Lean it back out a touch, but don't go quite as far as you did when you richened it.. Those Traxxas motors will run in the upper 200 range.. 300 is too high but 270-280 is normal for them..

Maximo

iTrader: (11)

i don't like tuning with the pinch test at all.....

nitroexpress

Your point?

ckblood05

iTrader: (15)

i think im pretty close. i was just running the rest of the fuel out and it was ideling pretty good and had good acceleration from a stand still. and the temp was between 240-245.

ckblood05

iTrader: (15)

well i try to go by how much smoke is coming out the exhaust and by sound. i kinda agree with ya, some people say 2-3 seconds, then some say 4-5, 7 seconds

ALLSPEED

iTrader: (4)

If yo have smoke then your right on point.

ckblood05

iTrader: (15)

yea, theres always smoke coming out. but there could be to much, or not enough. its tricky finding that sweet spot