Picco .21 Nitro RC Engine- Help Wanted (Tuning,idleing)

[ScottyNitro17]

Hi I'm fairly new to the whole Nitro stuff so this might be a little confusing on my part to explain :

For Christmas my Fiance got me a Custom Built Nitro RC Monster Truck from TRAXXAS, It was fully broken in and tuned to run rich but I've been told by the guy who built it that I need to tune my Picco .21 engine but If I'm honest I'm terrified of going near that Engine for risk of destroying it (As buying a new engine then having to Install it will be far worse than having to tune it) But I know that It does need to be tuned since 1.As far as I'm aware it drains less fuel and will reduce my fuel waste , 2.It doesn't Idle well, It will last about 2-4 seconds when cold and even at 100.c+ it idles for 4-7 before cutting out , So what I really need help with is how to tune my engine correctly without damaging it, whats the temp limit, how do I keep that engine singing away without stalling and If there is anything else I should know about it ? I'll leave some pictures of it below if it helps :

 

[Paul]

Ok so the first thing you need to do is determine the factory needle setting for the Picco. Just go to their website and find the PDF manual for the Picco you have.

Take the air filter off and make sure the carb-slide gap, at full break, is about 1mm. May wan't to remove the venturi (carb instert) as it can sometimes obstruct your view if left in while setting the gap. The carb-slide gap is in my opinion the most important setting. You start your tune from here and you have to make sure it always returns to the gap you set when you actuate the throttle on your transmitter. Good idea to use a rubber band and wrap it around the throttle horn (under throttle link) across the carb and around (on to) the fuel inlet part of the carb (the stump your HSN screws into)...once your sure the carb-gap is gtg.

Now with the factory needle settings set warm the engine up with a hair dryer or heat gun, 5min will do with hair dryer. Once the engine is really warm to the touch your ready to tune. If you don't have an temp gauge get one because you don't want to go wide open throttle unless your sure the engine temp is 200 or better and really shouldn't go too hard until you've put about a gallon through it. Now follow these guides.

Also, welcome to rcnt! If you get hung up on anything give a shout. Just follow the steps and you won't ruin your engines, ever. At least not because of a jacked tune. Nothin like gettin one of these little screamin demons broken in and tuned for the first time. I was so nervous the very first time I started my engine that I tried for like 5 min without the glow ignitor attached...flooded engine, fuel pouring out of my exhaust.

Another thing, adjust the air inlet tube so its not so close to your flywheel. Also all of the guides here in the RC NitroTalk forum are excellent. If your supper wet behind the ears start with the Read This First! Guide. If you grasp what the function of the carb is and why you set it up with about a 1mm gap and are mechanically inclined start with the tuning guides.

 

[Paul]

A word about max engine temp. I'm completely unfamiliar with Picco engines and what temp they like to run at. Regardless I would say above 200F and below 280F should be safe. My engine likes it around right around 240F. You really just want to make sure it isn't getting scorching hot and focus more on the other characteristics of a good tune. Smooth idle, just visible stream of blue smoke at WOT, responsive throughout the throttle range and always drops back to that stable idle.

Last thing...maybe (lol) Should clean that puppy up and post after pics

 

[Nitrotrout]

One more thing to add...look into getting a temp gun to take your readings. Those on board temp gauges give off inconsistent readings which can ultimately effect your tune. Decent temp guns can be bought for $20.00 give or take.
One final note, don't depend solely on temp readings to tune your engine. Temp readings are generally a guide to get you into the ballpark.

That's some good advice listed above. You should also check out Uncle Rolex's tuning chart. Rumor has it he created this chart while wearing no pants. Incredible.
https://www.rcnitrotalk.com/forum/threads/nitro-tuning-tips-and-tuning-flow-chart.60832/#post-537066

 

[Paul]

That's some good advice listed above. You should also check out Uncle Rolex's tuning chart. Rumor has it he created this chart while wearing no pants. Incredible.

All we really know is.....THEY CALL HIM THE Rolex! Clearly I've watched to much Top Gear.

 

[ninnon]

Firstly, check out Rolex's tuning chart, otherwise, don't be too worried about destroying your engine- it's pretty hard to do! As long as you don't let your temperatures go above 220, and it doesn't scream, then your fine. To start off with return to stock settings (picco website) then get it so that the idle is higher than normal and warm it up, after, dependent on the temperature, slowly lean out the hsn, then re-do the idle again. If your a newbie then don't worry about the low speed needle too much. But again it is just the same as the hsn- just lean it out until you've got optimal acceleration, but it doesn't bog down or do anything odd.

 

[Paul]

As long as you don't let your temperatures go above 220....

Have to ask. Is that for the Picco he has or maybe a typo?

 

[ninnon]

Have to ask. Is that for the Picco he has or maybe a typo?

Yes, I am talking about his engine.

 

[Paul]

Yes, I am talking about his engine.

OIC. Was like "Wait a min my engine gets quite a bit hotter than that." Different engines different characteristics.

 

[ninnon]

OIC. Was like "Wait a min my engine gets quite a bit hotter than that." Different engines different characteristics.

Yeah, here in the U.K it's always cold so that's as high as I let it go in winter because then it'll be running to lean and i'll kill it

 

[hulkmaxx]

Those Picco's will let you know if your to lean or to hot! They get the chewbuca idle after a WFO pass. That style Picco has been some of the best engines I have ran. Best temps to keep are around 220-230 for best performance but like Trout said temps are not everything. Every mill has it's own characteristics it likes best. I have found those engines really like a medium to hot plug also best.

 

[ninnon]

Those Picco's will let you know if your to lean or to hot! They get the chewbuca idle after a WFO pass. That style Picco has been some of the best engines I have ran. Best temps to keep are around 220-230 for best performance but like Trout said temps are not everything. Every mill has it's own characteristics it likes best. I have found those engines really like a medium to hot plug also best.

Yep, each mill has its own characteristics- in my stock engines case, not good ones!

 

[ScottyNitro17]

Just want to thank you all for your helpful replies I'll be getting my RC tuned soon since it tune's out my father-in-law used to repair old cars that use the same type of ways to tune with 3 needles just like a Nitro does so fingers crossed that goes well but after a misunderstanding with a puddle I have caused some upset with my easy start motor which needs replacing and aslo need a new glowplug which I burnt out from either an over rich or lean mixture which will soon be fixed but after the puddle trouble (hey that rymes xD) I'm taking it to a RC shop to get a free check out incase anything else is damaged or water got into the carb or something, Fingers crossed that isn't the case eh Thanks again for your feedback

 

[ninnon]

Just want to thank you all for your helpful replies I'll be getting my RC tuned soon since it tune's out my father-in-law used to repair old cars that use the same type of ways to tune with 3 needles just like a Nitro does so fingers crossed that goes well but after a misunderstanding with a puddle I have caused some upset with my easy start motor which needs replacing and aslo need a new glowplug which I burnt out from either an over rich or lean mixture which will soon be fixed but after the puddle trouble (hey that rymes xD) I'm taking it to a RC shop to get a free check out incase anything else is damaged or water got into the carb or something, Fingers crossed that isn't the case eh Thanks again for your feedback

Sounds good, if your still stuck on tuning there are plenty of tutorials online and then there's ERCM's tuning guide found here:
https://www.rcnitrotalk.com/forum/threads/rc-nitro-engine-performance-tuning.102688/
Hope it helps