Losi 5ive T 2.0 Backyard Bash. Still working on tune.

[Picodogg]

Just doesn’t sound right… idk

 

[Rep732]

@Picodogg sounds just fine to me

 

[Picodogg]

Took the body off and it looks like I bent a brake rotor. There’s a ringing I was hearing, that or I think I am hearing it hit the pads as it turns.

Either way new Detroit brakes show up tomorrow.

 

[Rep732]

Bent brake rotor? That isn't an easy task, you'll hear a chime noise from the lash of the pinion and spur. Any pics of this bent rotor?

 

[Picodogg]

Will get a pic of rotor tonight.

Working on tuning. Adjusting it like a milllion times now. Seems to be a ton of different ways, but the best way is to saw the plug apart?

Oh and I found this guy to explain carbs. Not sure if this accurate for RC?

 

[Rep732]

Tuning isn't this hard. If you lean it out you'll hear the engine break up or bog and won't sound crisp. To rich and the engine will just be sluggish

 

[Picodogg]

Tuning isn't this hard. If you lean it out you'll hear the engine break up or bog and won't sound crisp. To rich and the engine will just be sluggish

The OCD struggle is real.

 

[Rep732]

@Picodogg sometimes things are just a set it and forget situation. Once I achieve the tune I like and its safe I'll never touch the needles again.

 

[Picodogg]

Ahhhhh… okay that makes sense. I keep thinking the needles are moving after I run it.

I even had this thing up on a stand with different servo endpoints at 30%, 60%, etc throttle to listen for the “best” sound on the low needle followed by the high needle. The Venturi on the high makes the fuel whirlpool in the bulb (I was even thinking of looking for the best setting to throttle for when you can tell the Venturi kicks in. Keep in mind I have no idea what the best sound is, but GD’t I am gonna run enough empirical evidence to find out. I’d then run it and to see if the acceleration was best with whatever settings I had.

To take it even further I’ve been videoing the runs to see how the sound and performance compares to other similar zen 320s with a silenced pipe.

Analysis paralysis. I know I told you I am/was an engineer. I didn’t tell you I was a good one.

My last settings below.

Changing the brakes tomorrow hopefully, but want to see any thoughts on the stock rotors if the bend is okay. Will post a pic.

 

[Seandonato73]

First the venturi always works. This isn't a 4 barrel carb waiting for the secondaries to kick in. Don't even bother to think about it operation like that. The transition your (most likely) reducing to is the engine getting on the pipe, or possibly transitioning to the main jet. Its not really difficult to set the jets. Low is arguably easiest. Get the engine warmed up, turn either direction and listen for a rich bog then lean rpm pickup. Go right in the middle between those 2 points. Start running it looking for transition, should be crisp not bog. Don't get the carb low to high jet transition confused with getting on the pipe, that's 2 different things. Then go about tuning the top end. It's a hearing thing for me, get the most rpm without breaking up then enrich the high needle a tad for a little safty margin. You should recheck the low jet. There is a little over lap between the two jets. You shouldn't have to be constantly changing the tune, unless there's a major temp swing, fuel/oil ratio change, elevation etc.

 

[Picodogg]

First the venturi always works. This isn't a 4 barrel carb waiting for the secondaries to kick in. Don't even bother to think about it operation like that. The transition your (most likely) reducing to is the engine getting on the pipe, or possibly transitioning to the main jet. Its not really difficult to set the jets. Low is arguably easiest. Get the engine warmed up, turn either direction and listen for a rich bog then lean rpm pickup. Go right in the middle between those 2 points. Start running it looking for transition, should be crisp not bog. Don't get the carb low to high jet transition confused with getting on the pipe, that's 2 different things. Then go about tuning the top end. It's a hearing thing for me, get the most rpm without breaking up then enrich the high needle a tad for a little safty margin. You should recheck the low jet. There is a little over lap between the two jets. You shouldn't have to be constantly changing the tune, unless there's a major temp swing, fuel/oil ratio change, elevation etc.

Was this somewhere else on the site? This is the easiest and most concise explanation to understand for a FNG.

 

[Seandonato73]

Yes, we've covered tuning basics a few times...

 

[Rep732]

It's a sticky in engine and exhaust sub forum.

 

[Picodogg]

Guess I didn’t look hard enough I saw thread with the argument about how to tune and it had a couple of different ways and plug chart. Oh well.

 

[Ides28]

these aren't nitros, the tuning window is pretty big and flat. how often do you tune your string trimmer? if it's not bogging or too lean you're fine, pretty much if it runs ok you're good. you don't get as much performance increase the closer to lean you get. your losi seems to run fine just don't run them too lean, you can damage them this way.