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Picco is finally set and dialed in!!!!

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T

Throttle

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East Aurora, NY
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I finally dialed in my Picco .26. What a pain in the a$$ compared to my .21 BB. If your not within an 1/8TH of a turn, it runs like crap. I held on to my truck to set it because I was so sick and tired of following it around everytime it died. If anyone buys a Picco and it keeps dieing out don't give up because when it is dialed in it's like night and day from a .21. All fours were spinning and running like a monster. If you are new to R/C's take the time to learn the hsn and lsn or you will get frustrated. It is worth the wait. I can't wait to kick the crap of of this truck and see what it can really do tomorrow.

Later.
 
It still might not be right, since you were running it without a load on it.
1/8 of a turn on either needle can make all the difference on any engine. It also needs to be tuned while it's at running temp. Trying to tune a cold or cool engine is useless.
After tomorrow, if you have problems, post again and we'll give you the info for getting it right.
 
I live in Seattle.

I replaced a TRX25 with a Picco .26 and a conversion.

You couldn't ask for a more obstinate climate for difficult tuning.

But you're right. The Picco .26 kicks ass.

tuning.gif
 
My problem was when I gave it more than half throttle it would die out with a temp of about 225. So when I held it it and it died at about half throttle with a load on it (me holding it) and running at about 220 to 240 I then made adjustments. I did run it around the lawn to get it to a higher temp. After running one tank it went to about 270. The second tank was about 285 and if I adjusted it 1/8 TH to the rich side it would run like a$$. So after seeing it pull wheelies and give good smoke I am off to the lhs to buy an OS#8 cold plug to help my temps and adjusting.
 
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Dubya is definately right there the Northwest is damn difficult to tune in. It can be 80 and sunny one day and 45 and raining the next. Scott let me know how you come out on the cold plug I have been running the #8 but in a medium and it is running too warm for my tastes. Yeah scott gives good advice on being patient with this engine it just takes the right touches but once ya get'em u'll be golden.
 
I dont know guys, I'm no engine expert by any means but my Picco .26 was installed, broken in (about 5-6 tanks of heat cycling), and doing backflips in the same day without ever going over 270. I have run her about 3 times since then and I never once had a problem with her dying on me. I still have an issue with it sort of bogging a little bit at about mid throttle but it never died.

Maybe I've just been lucky.
 
I also reside in the Northwest (Oregon) and have a picco in my Savage. The thing is like a dream. I am running MC-59 plugs (hot) and my temps never get above 245 and it screams. Did have to put an MC-8 in it one day and it ran like crap. Could not get it up to temp and adjusting the HSN just made it run too lean without fixing the temp problem. Put another mc-59 in it that I stole from my buggy and all was well again.

Did you seal up the backplate and carb as well as remove the needles and check for worms? Very critical with the Picco to do all that. When they insert the needles they often cut the o-rings and that leaves little rubber worms in there. Take the time to pull the backplate and carb and seal them as well as remove the needles and lube up the o-rings. Set back to factory (7.5-8.0 on LSN, not the 10.5-11 that it says in the manual) and re-tune. Should be a different animal for you.

Glenn
 
I did pull the hsn oring and it was shot. The barrel also has some tool marks from manufacturing. I cleaned them up and replaced the ring. Today I went out to run and still I am having some issues with it still dieing out and then when I adjust the hsn needle I'm then doing wheelies and then my temps rise up at the half tank marker (the leaning out issue with these tanks). As long as I keep the tank above the halfway point my temps are fine but why can't I keep the temps down?

And whenever I adjust the hsn out of the sweet spot it runs like a$$ and dies. After the rain ends I will change my plug also but will that help my head temps at all by going to a colder plug? I was told my lhs it won't do much at all. Anyone? Thanks.
 
Did you also seal the backplate and the carb? The best thing to do is tune at 1/2 tank and then just run a little rich when the tank is full. Your motor will thank you for that in the long run.

Just for shiats and giggles, try an mc-59 plug and see what happens. My Picco LOVES that plug.

Glenn
 
Glenn, I tried to tune at 1/2 a tank like I did on my .21 but if I'm off by 1/10th of a turn it seems the truck will just die and if I get it right at half a tank its to rich at a full tank and then it dies at half throttle. (I'm not giving in either and take to to the lhs, I want to figure this out so it helps me out down the road. Do you have any thoughts on this or could it be the backplate. And if the backplate leaks will it show?


I will try a mccoy 59 and see if it helps.


Thanks again for your input Glenn.
 
If the backplate is leaking or the carb is leaking you will never get it tuned and it will overheat.

Just so you know you are not experiencing an air leak, get some Permatex copper silicone sealant. Pull the backplate and clean with some carb cleaner. Put a thin coat of the copper sealant on the crankcase part of the motor where the backplate touches it. When you are done just run your finger around the inside to get the copper silicone off the beveled edge, that will insure no sealant in the motor. Put the backplate back on and tighten real good using criss cross pattern on the bolts to ensure an even tightness all the way around.

Now pull the carb out and clean that as well. You want to put a thin bead of silicone sealant on the carb itself right on the o-ring at the base of the carb (last part to touch the crankcase when you put it back in). Make sure you are pushing the carb in when you tighten the nut that holds it in place and make sure it is positioned correctly.

It is best if you let that sit for a day to make sure it all cures. Some grease or petroleum jelly on the needle o-rings and you should be all set there.

Now you have to make sure the needles are set to factory. Hsn is 4-4.5 (I think) and the LSN is 7.5-8. If you have the lsn set at the 10.5-11 like the manual says you will never get it to run right. I doubt you are there because if you were there is no way you would get it to run period.

Try that and an mc-59 plug and you should be dealing with a whole new critter. If that doesn't work, the only thing I know to tell you is to ship it to me, I will see what I can do and ship it back. Like I said, I love my picco and it holds a tune without any problem. I did all the above before ever firing it up. Good idea with any new motor to seal it up and check for any surprises like chewed up o-rings and such.

Keep us posted. That copper sealant should be available at any auto parts store.

Glenn
 
If your idle is good and you can get to half throttle smoothly, your LSN is about right. Adjust your HSN for full throttle. Do the pinch test on the fuel line when the engine is up to temp. 3 to 4 seconds is what you want. If it quits in less time, you are too lean on the LSN. More time, and the LSN is set too rich.
Factory settings are a good place to start when you can't start it, but since it's running, it only needs to be tweeked from where the settings are now.
 
Thanks again for the help Glenn. I will do the sealant tomorrow night. It going to rain here in Buffalo so during the rain delay I'll get it setup for my next run. Thanks.
 
Originally posted by scotthg1
Thanks again for the help Glenn. I will do the sealant tomorrow night. It going to rain here in Buffalo so during the rain delay I'll get it setup for my next run. Thanks.
Click to expand...

Tell me about it. It has been raining here in Oregon since Saturday. I am on vacation and can't even go play. Also hoping it clears up by the weekend. Got an XTM .21 Race Pro showing up tomorrow and want to get it into my Hyper 7 buggy so I can break it in and play on Sunday.

Keep us posted. Rolex also had some good points about lsn. Pinch test is a great way to double check that. I like 2-3 seconds and pinch as close to the inlet as possible without buring the fingers. Needle nose pliars work well with some fuel tubing over the tips.

Glenn
 
When I shut her down today Rolex I pinched the gas line and it ran for a few seconds and then it reved up and stopped. It just seems that I will have to adjust everytime I run and move the needle a 1/4 of a turn to get it set for that day. Then when it gets to half a tank I'll have to tweak again and that's not right. I will start from scratch again and fight my way through it, I will have to chalk this one up for a good learning experience. Thanks Rolex.
 

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