Hey People

I need a little help.... I have a Traxxas 2.5R Nitrol Rustler and the acceleration is really sluggish.

When the engine is cold it will wheelie and run really well with lots of power. But once the engine has warmed up to operational temperature i find that the acceleration is really poor and sluggish. Once the engine reaches top revs it runs fine. I think it has something to do with the low speed needle.

The engine is brand new and has lots of compression. Can you guys give me some tips on how to tune the low speed needle please.

Miles

Hello miles welcome to the site mate :thumbs_up:

Do you have a TRAXXAS manual? that will tell you everything you need to know about running, tuning and the maintenace of your TRX engine.

But if not heres one for you and some info to follow.

http://www.traxxas.com/PDF-Library/4409_manual.pdf

Have a good read of this manual mate, it is very helpful :)

Where you say,: once the engine has warmed up to operational temperature i find that the acceleration is really poor and sluggish. What is the temperature of the engine??? It should never go above 270° F, if it is its running too hot..

As long as all other needles have been set correctly and your engine is not running too hot, Your issue does sound like an adjustment issue on the LSN, should be easy enough to sort out. :thumbs_up:

Low-Speed Fuel Mixture Adjustment

The low-speed mixture is always set after the high-speed needle is
correctly adjusted. The low-speed mixture is set using the pinch test.

1. Once the engine is warm, do several high-speed runs to confirm
that the high-speed needle is set correctly.
2. Bring the vehicle in and pinch closed the fuel line going into the
carburetor (use the engine shut-off clamp). The engine should run
for 2-3 seconds, speed up, and then shut off.
3. If the engine runs longer than 3 seconds, then lean the low-speed
needle 1/16 turn, make several more high-speed runs, and retest.
4. If the engine shuts off immediately without speeding up, then
richen the low-speed needle 1/8 turn, make several more highspeed
runs, and retest.

When the low-speed needle is set correctly, the engine’s throttle
response should be very quick, even to the point of making it difficult to
keep Nitro Rustler from doing a wheelie when you accelerate!

Hope this helps a bit mate, let us know how you get on.. :cheers: :thumbs_up:

HAPPY RC-ING :rc_car:

Thank you mate :)

I know its something to do with the mixture as there is alot of unburnt fuel around the engine. I dont thing the engine is running too hot as i have done the water test and it just simmers away (if that makes sence).

Is it best to put the engine back to factory settings and go from there?

Thanks for helping.

Cheers

Miles

Hi mate, your welcome :thumbs_up:

Yeh id put the engine back to factory settings thats a good idea. :)
Then follow the manual to retune the engine, then fingers crossed it should run sweet.

Where abouts do you live mate?

Im also running Model Technics Big Bang 16 fuel which i have been told is rubbish. Gunna try and get some Byron Gen2 see if that helps.

I live in Weston Super Mare in Somerset. Its a shame there isnt many RC clups around :(

Arh yeh, its a shame you dont live closer to me mate or we could have meet up and i could have help you tuned the rustler..

Yeh mate model technics is not a very good fuel, in fact, when people come on saying they are having tuning issues, about 90% of the time they then say theur using model technics fuel lol..

You can easy up your nitro percentage to mate, we use byron 25% fuel on our 2.5 t-maxx's, revo, and jato.

But if you do up the % you will need to do a basic run-in again on your engine and retune :thumbs_up:

I think ill keep witht he 16% just cus the engine was run in on that. Just got my Byron fuel today in the post :D

Once the weather get better ill try tunning the engine and ill let u know :)

Cool mate, look forward to hearing more, good luck :thumbs_up:

HAPPY RC-ING :rc_car:

Hey mate

Good news!!! Used the new fuel put the settings back to factory setting and only had to turn the LSN 1/16th of a turn.

The engine is running sweet :D!!! the bad news is i have ripped to shreds the Idler gear haha bad times but at least the engine is great :P the car wheelies down the road!!

Once i get the Idler gear what is the best grease to use in the transmission?

Cheers

Miles