Trx 2.5

Plug

Hi anyone with a traxxas vehicle fitted with the new TRX 2.5 racing engine. I got my engine broke in over a week ago and when I tuned my engine every thing went haywire. When I start my engine it idles for 2_5 seconds and then cuts out.
When I fiddle about with the needles it can idle till the tank empties and when I slow down without using the brakes after a high speed run it idles but if i use the brakes to slow it down it cuts out. When i was braking in the engine everything worked proberly.Any ideas in what I should do.

Darren_______Kilkenny

2 Espressi

have you tried setting the throttle trim a bit higher?

Plug

I tryed that but the car kept moving and when I pressed the brakes it cut out. I think i know whats wrong, I set the trottle trim to high but I should have set the idle set screw 1mm away from the slide carb. I,ll do that later. Thanks for the help anyway.

Darren_______Kilkenny

coolwings

Plug wrote:

.... but the car kept moving and when I pressed the brakes it cut out.

3 possibilities ...
A
The idle is too rich, slowing idle speed, and when you select lowest throttle it just cuts out ... cure ... lean idle a little to raise idle speed above cutout when throttle stick is full down
B
The governor screw is not preventing the total closure of carburettor when throttle stick is full down ... there should still be a 1/4mm - 1mm gap for air.
Cure ... adjust the governor to stop total closure of carb barrell.
C
The clutch is burnt out, from being in gear at same time as car has brakes on. Symptom is car is in gear all the time, spinning 2 rear, or 2 front wheels simultaneously (in the same direction) tries to turn engine over. ie Clutch does not allow decoupling of engine from wheels when tested this way. Cure...cut out the melted clutch and fit a new clutch.

Cheers
:cool: :cool: :cool:

Plug

Whats the governor screw. I only know the idle stop screw, rich needle screw and low speed screw. Were is it on the carb.

coolwings

Plug wrote:

Whats the governor screw. I only know the idle stop screw, rich needle screw and low speed screw. Were is it on the carb.

Gvernor ... idle stop...
Same thing ... two names, it stops the carb from closing fully, when screwed in.
BUT ... only adjust it when at full throttle, then throttle down to monitor the effect of the adjustment. If you screw it in when throttle is closed, the tip of the screw breaks.

Plug

coolwings wrote:

Gvernor ... idle stop...
Same thing ... two names, it stops the carb from closing fully, when screwed in.
BUT ... only adjust it when at full throttle, then throttle down to monitor the effect of the adjustment. If you screw it in when throttle is closed, the tip of the screw breaks.

So I just open the trottle with the trottle trim, tighten or losen the idle stop screw and when I leave it idle the carb should be slightly open. Thanks

Darren___________Kilkenny

Plug

Thanks coolwings I got the truck up and running.

goldwing

Plug wrote:

Hi anyone with a traxxas vehicle fitted with the new TRX 2.5 racing engine. I got my engine broke in over a week ago and when I tuned my engine every thing went haywire. When I start my engine it idles for 2_5 seconds and then cuts out.
When I fiddle about with the needles it can idle till the tank empties and when I slow down without using the brakes after a high speed run it idles but if i use the brakes to slow it down it cuts out. When i was braking in the engine everything worked proberly.Any ideas in what I should do.

Darren_______Kilkenny

Hi plug my name is goldwing Iam from america but I moved 2 Kilkenny about " weeks ago I cant make heads or tails of the place do u live in the tow & do u no anywhere week could meet up & race. By the way I have a CEN MT2.

coolwings

Plug wrote:

Thanks coolwings I got the truck up and running.

That's good news. Enjoy.

BTW I go to Kilkenny weekends maybe every 8 weeks.
Usually I don't take a model, (fills the car up pretty fast), but some of the other Kilkenny guys asked me take them next time. They (some) are near the airfield and others also at Thomastown . I haven't done RC in Kilkenny city so far, there could be a first time though.

I'll send a PM when I'm going there next time (assuming its weather OK conditions).
:cool:

Plug

ill get back as soon as i can,my computer exploded im in huston station writing this message.

Plug

I know this thread is a bit old, but anyway the other day I fired up my engine for the first in about 2 months, the engine start acting strange pulling wheelys at a bare touch of the trigger :eek: and started over heating.
So I set it back to factory settings, that was worse, anytime I applied trottle it cut out. Is it to rich or lean
I keeped my fuel in the shed for ages, Its cold but not damp, could the fuel be my problem

.B.R.

Sounds like your too rich... Lean the low end 1/8 of a turn and try it out..

coolwings

Maybe too rich...
but I would bet it's too lean because you say the engine is racing.

Odds are that some fuel dried out in the fuel line and carb inlet nozzle, while it was stored.
the methanol evaporates out the carb air inlet, leaving the 20% oil behind in a thickened gel type form.
Kinda like clogging of the arteries. Less fuel gets to the engine than you think judging from the carb setting.
To wash it out fill up the tank and open the throttle full, prime and deliberately flood the engine, leave it for a while to soften up the gel.
Empty the tank again.
Then take it to a filling station tyre pump and blow some compressed air into the carb air inlet, and then into the tank. Concentrating in the place where the fuel goes into the carb from the tank.
Be sure to close your eyes and mouth while u do this.
Then fill the tank and start it.
Probably problem is gone, but you may have to open the carb needle a 1/2 turn extra & run rich for a tank to wash away some persistent residue.

SLIM19198

Factory settings for a 2.5 engine are way too rich, but you are popping wheelies on take off???

I would say lean it out a bit but the wheelies are weird!

Plug

Yeah thanks coolwing i,ll try that later, but I usally clean out the engine and pipe lines when I store it. It used to run grand before I stored it. I use hobbico afterrun oil, maybe I put to much in . Oh slim19198 them whillies were strange but true, never happened before on the rich side :eek: .

coolwings

The worst blockage (if that is the cause) will be between the fuel inlet nipple on the carb, and the place that the main needle screws down into.
Once in a while you can take out the needle, blow in the tube, and actually see the lump of gunge trying to go up the fueltube towards the tank.
BTW Thats why I only have clear fueltubing.

Plug

How about if I take the whole thing apart wash it with warm water and then spray WD40 on it, would that ruin the carb

CHUCKLEZ

well if its popping wheelies id say its ur low speed needle is set way to high or else some 1 swap ur engine lol