Sirio .18 Help

[NJRC]

I am really new to R/C trucks and just bought a used TMAXX that was completely modified by a R/C hobby store owner. On my truck I am trying to get familiar with the parts mostly about the engine. I have a Sirio .18 motor with pull start and was wondering if there was any manuals out there from Sirio that canbe downloaded or any tuning tips especially with identifying parts on the motor to adjust possibly through photos?
I would appreciate any help from you guys out there that are familiar with this Sirio motor.

Thanks
RJ

 

[GilBeQuick]

Hmm....have you ever had anything that was nitro before? What I'm getting at is, do you have any nitro engine experience at all? Are you able to identify the high speed needle or the low speed needle on the carb?

How does the truck run now? Does it perform badly?

 

[NJRC]

I have absolutely no knowledge of nitro motors or anything about my truck at all since I am new and willling to learn just by talking to experienced guys and those who have been there and done that.
I am not famliar with the parts of the carb or engine on nitro R/C's but I do see two screws that would seem to me as adjusting screws for the carb. One pointing up and one pointing to the side. I would assume that the high speed needle is teh one point up and the low speed needle is the one pointing to the side??? Am I right so far???
It seems to run OK....I think but not really sure since I don't know much about it's "real performance." I have read around that the motor will allow my TMAXX to do wheelies but I have not seen one wheelie pop yet. I have also read around that hot temperatures to the motor will allow it to run good. It does take me several pulls to get it started and once I pull the glow plug starter off on a cold motor, it will die unless I keep the glow plug starter on it for a minute or longer to warm things up. Is all this normal???
See my photo of my motor.

Thanks
RJ

 

[RatzoRC]

you are correct about the high and low speed needles.
If you want to lean it out, or make it run hotter, you have to turn the screw in (clock wise) usually on the hi speed needle. but of course, the more you lean it out, the less oil into your motor, the more wear on the piston.
For wheelies, it would be the same on the low speed needle.
Make sure that you get a manual on the screws locations so your not messing with the wrong ones.
High speed needle, top end
Low speed needle low end power.
Theres lots to consider when setting your motor up.
longevity, performance, things like that.

 

[El Pirata]

First off lose the boost bottle. It's an ounce of needless weight and the things are worless as far as performance. But if you're going to the "cool" look leave it.

 

[NJRC]

If I lose the boost bottle, do I have to put a plug from where that line came from?
I finally found out where Sirio came from....TeamTrinity....Duh?
on their site it says two different tuning settings for the .18TX which also confuses me. The settings are as is:

Setting #1
Header: Cut 3/8” back
Ambient temp: 32-40F (yeah.. it's cold in Jersey!)
Plug:
Standard: Nova Rossi #C6
Turbo: Nova Rossi # C6TGC
Mid Range: Fixed
High End Needle: 7-1/4 to 7-1/2
Low End Needle:1-1/2
Fuel: Trinity Power Blend 20% (MH0020 Qts / MH4020 Gallons)
Head Shims: Standard (1 thick/1 thin)
Receiver pack: Trinity #5304 5 cell (Needs female end to be soldered)

With higher ambient temp it is advisable to use #7 plugs from Sirio or NovaRossi
and recheck settings. They may need to be changed to a richer setting. We have found
using Nova Rossi Plugs gives the best performance under these cold conditions. We also
used Trinity 8100 glow Ignitors for quicker starts with the cold weather.

-----------------------
Setting #2
Sirio .12/15/18 (General Carburetor Settings)
High Speed - 5.5 turns
Low Speed - 2-1/2 (Generally this should be flush with the end of the slide)
Mid Range - Flush then one turn out.


Thanks
RJ

 

[lykan]

Ok, The high speed needle's and easy one, but you didn't mention and idle screw.

If you can get pics of all the needles/screws on the carb, we can tell you what each one is for.

If I were you I wouldn't adjust the midrange screw at all. The low speed needle is a sensitve beast too, and can be a pain in the ass if you get it out of whack..

Get some pics of all the screws, and we'll tell you what each one is.

I should have mentioned this first, but if you are going to tackle tuning by yourself, I would definetaly invest in a handhel temp gun ($25) at radio shack..

You've stumbled upon the best forums on the net (IN my opinion) Lots of knowledgable guys here, and none afraid to share.. Weclome to RCNT

 

[NJRC]

Well thanks for any help offered.
Here are pics of screws I found around the carb area.
In the first photo, there is actually a screw that cannot be seen in the photo which is just right behind the yellow hose and seems to look like an adjusting screw for the carb. All the rest of the screw on the motor look pretty much for mounting the motor. I counted 3 slotted screws and 2 hex shaped screws on the carb.

Photo #1

Photo #2

 

[lykan]

In the first photo, the brass fitting with the fuel hose attached is your High speed needle.

In the second photo the larger screw in the center is your Low speed needle I belive.

The screw we can't see unless you remove your air filter I belive is your idle screw, does it have a spring underneat it? between the crew head and the carb?

The smaller screw in the second picture that is off to the right appears to be your midrange needle


The High speed valve controls how much fuel flows into the carb.

When your throttle is at 100% every other needle is wide open, and the High speed needle controls all the fuel flow. If you close this needle all the way, no fuel goes to the carb, all other needles are downstream from that.


The low speed needle affects fuel flow from 0- about 45% throttle it regulates the fuel comming from the high speed needle. Once you hit 45-50% throttle, the LSN is completely wide open.

The LSN controls fuel flow at idle, and fuel in the carb when you stab the throttle off the line

The HSN controls wide open fuel

The Idle screw only controls how far the carb is open at 0% throttle . The more you tighten that screw, the wider the carb opens and the higher the idle.

I hope that helps.