Ofna Picco 26 crappy carb. Any suggestions?

[Error401]

I got a Picco .26, and it's about broken in now. Temps and tuning are within reason, but It's blowing raw fuel out of the HSN. It also seems to be very rich at about 1/2 throttle, and there's no MRN to adjust.

The HSN housing and fuel inlet collar/nipple are "sealed" with two aluminum washers (similar to the copper glow plug washer). The area that the housing threads into is also aluminum, as well as the housing and the collar. I'm reluctant to wrench down on the housing to try to get a better seal because of this fact. The Hyper 8 and the 21BB both have fiber based gaskets and they do not leak. I am going to try to use the HSN, collar and gaskets off of my 21BB on the Picco carb to try to get it to stop leaking. I have disassembled the carb to check for crap, but it was clean, though the secondary o-ring on the LSN was about chewed up. The other o-rings are good, including the HSN ring, so that's not where it's leaking.

The other major problem I have with this carb is the midrange mix. It'll idle all day, and run WOT all day, but it loads up around 1/2 throttle. If I ease into the throttle and run for ~20 to 30 feet the engine accelerated fine, then slows as it loads up. When I go WOT from there, it's real sluggish, belched a ton of smoke and eventually clears itself. IMO this sucks. If this is normal for this carb, what would be a good replacement to correct it?

Thanks,
Whitt....

 

[imnotsure]

try here http://pub77.ezboard.com/fofnaracingnitrotalkbackfrm26

this is the only place that i've found but read at your own risk.

 

[Error401]

Thanks INS, I found this thread on the link you sent.

http://pub77.ezboard.com/fofnaracin...essageRange?topicID=46.topic&start=21&stop=40

I have the silver LSN, and the general concensus on that board is that it is the wrong LSN.

If anyone else is running the Ofna Picco Outlaw .26, let me know what LSN yours has (silver or black) and tell me how yours is running.

Thanks,
Whitt...

 

[imnotsure]

i'll tell you what i had to do. by the way, i still have the silver lsn. i had to completely and totally ignore the instructions that were given w/the motor. i'm sitting at about 5-1/2 out on the low side, and not exactly sure where i'm at on the high side, due to the fact that i'm waiting on my o ring to show up. but, after installing a nova head to keep the temp. down so i can run it a little leaner, i'm somewhere in between 240 and 260. and that's w/many wot runs. my biggest problem has come from the hsn oring, it was crap straight out of the box. i don't know how many times i've pulled rubber out of it, so i think it's best to just go ahead and replace it. although, on my search to find one around my neighberhood, the only place that spec. in orings and gaskets, they measured it and found out it was a metric oring. so i ended up ordering one from nitro house today. i'm thinking about calling them back and ordering the lsn and orings since i already have the hsn on it's way. for $8.00 shipped, it's a cheap try.

sorry, i was interrupted on a spelling test. 1 thing i have learned is the picco carb is a pain in the ass to tune. but once you get the oring and needle issues over with, i don't think you'll have a problem w/the carb. like i said, before i completely stripped out my oring, i was keeping it at a good 240, and have plenty of takeoff, top, mid, etc. etc. everything was good. you just have to play w/her. also it wouldn't hurt to seal everything that can be sealed. also, i was thinking about sealing the alum. to alum. fitting on the high side w/some silicon when i reinstall the hsn. i don't think it would hurt anything as long as you don't get anything past the threads.

 

[007kel]

I have the silver lsn for my picco 26 for my kyosho inferno. I've had problems with this engine after tank #3. I never could get the carb settings to settle right. I called OFNA customer service, but they were not much help. They gave me the part number to the black lsn, but could not suggest if it would help my situation. It's like I was giving the answers to them:

Kel: So will the black lsn work, will it solve my problem?
Ofna C.S.: Yeah, sure. Here's the part number.
Kel: Will replacing the carb with another 21 engine carb help?
Ofna C.S.: Yeah, that could work also.

I tried my 21BB carb on the picco 26. It worked...for a while. Then the temps starting running up. I would richen the hsn, then the engine would load up. I finally took it to the hobby shop. They got the picco running with the stock carb. I managed to run it for one tank...finally! But after that, I could not get the engine running well again.

Now, at WOT or at 1/2, it seems like it's blipping. I checked my servos and it's wires, no glitch. I checked my failsafe, and that seems to work fine. I can't figure what it could be right now. I still haven't had a consistent run with this engine. It's too frustrating...sorry if I'm venting.

As far as taking apart the carb, I never had any experience doing that. Sounds like what you guys are doing is a good idea. I don't know what I'm going to do, but this engine is taking it's toll with me. I'm just going to save up for another engine. For now, I'm thinking about replacing the gas tank. I'll see if that will stop the blipping.

 

[Error401]

Well, I was gonna change the HSN, HSN housing and fuel nipple, but decided to change the whole carb instead. I pulled the stock carb off of my spare 21BB and put the micrometer on it. I think the problem you had Kel, was the carb throat opening in the 21BB is quite a bit smaller than the stock carb on the picco. This translates into not enough air getting to the engine no matter what needle settings you tweaked. So, out comes the drill, a 5/16th bit, the dremel, polishing felt, some really fine grit sand paper and a piece of arrow shaft. I wish I had taken some pix.

Anyway, I bored out the 21BB carb throat, polished the venturi (cause it's sand cast stock), and am in the process of honing out the tool marks that were left from boring. If this works, and I don't see why it wouldn't, I'll let ya'll know.

Whitt....

 

[imnotsure]

ERROR: since you have the means to measure the throat where the carb. goes into the housing, cuz it's kinda a controversial thing, i've seen someone saying it's 7mm, some said 8mm, i don't know what the hell it is. one person says it's a perfect fit, the other says it's not. there's supposedly an adapter for this somewhere on the market. this is what i'm talking about:

http://pub77.ezboard.com/fofnaracingnitrotalkbackfrm26.showMessage?topicID=39.topic

 

[wdavidhicks]

Well damn. This isn't very reassuring.

I just got my Outlaw in the mail a week ago. It's one of a whole bunch of pieces that are part of a .21 conversion and I don't even have anything together yet. Had to return a UE7.5 diff case to UE. That's another story.

I do have the silver lsn. There doesn't seem to be a throttle return spring on the carb itself. This is normal, right? The rubber throttle boot relaxes at almost WOT.

 

[Error401]

Originally posted by imnotsure
ERROR: since you have the means to measure the throat where the carb. goes into the housing, cuz it's kinda a controversial thing, i've seen someone saying it's 7mm, some said 8mm, i don't know what the hell it is. one person says it's a perfect fit, the other says it's not. there's supposedly an adapter for this somewhere on the market. this is what i'm talking about:

http://pub77.ezboard.com/fofnaracingnitrotalkbackfrm26.showMessage?topicID=39.topic

Ok, the opening in the crank case (where the carb goes into the case) is 13.97mm. The dimension that you stated is the throat opening in the carb where the barrel is. The opening at the top of the carb is bigger than that, but tapers down to form a venturi, which increases the velocity of the air at the spraybar, which makes it draw fuel easier. Kind of like an airbrush. Anyway, what they're talking about is that dimension. and on the Picco, it's 8mm. If you look at the picco carb, it's composite, and you can pull the aluminum insert out and mic the diameter at it's narrowest end. It's not easy to do it from the outside. So, with that in mind, you can't do the same with the 21BB carb, but it looked like I was drilling out about 1 to 1.5mm diameter from that carb, which would mean that it was about 6.5 to 7mm throat opening.

I got it back together and it looks pretty darned good, feels good too. I'm going to try to run it tomorrow, so I'll let you guys know how well it worked.

INS, I hope I answered that for ya. If not let me know.

Dave, be prepared for the mid range load up. Also, keep an eye out for fuel leak at the HSN housing, I hope your's doesn't, but the LSN seems to be a problem. No, there was no TRSpring with mine and no header. No sticers also, that sux cause the hyper 8 does come with both of those.
Whitt....

 

[imnotsure]

thanks, you pretty much cleared it up for me. that's why i gave you the link. i wasn't sure if i explained myself very well. but where you came up w/the 8mm was the the question i was trying to ask.

 

[wdavidhicks]

The THS pipe has a good fitting header. The pipe was made for left-side mounting so the orientation of the spring-mount holes is off a little bit. I can drill new ones there.

Whitt, did you mean no stickers? (I had to make sure "sticer" wasn't a word before I asked!)

I didn't get any stickers the Hardcore .21 kit OR the Picco engine OR the UE7.5 diff kit!!

 

[Error401]

Yeah, I meant stickers. No sticers with the Picco, cool sticker sheet with the hyper (though I can't find them now).

What are you gonna put your picco on? I'm gonna go out on a limb and guess a T-Maxx.

 

[wdavidhicks]

Yep. Click my sig and then click the link "The Ride".

I have to have the diffs together before I can start assembly, and I've got a diff case that's going back to have a helicoil replaced.

I'm starting the transmission work with the RRP FOC gears and double-slipper for now.

 

[Error401]

Originally posted by error401
Yeah, I meant stickers. No sticers with the Picco, cool sticker sheet with the hyper (though I can't find them now).

Stoopid keyboard, the K key is working now.

Nice ride Dave! I'd like to see under the hood sometime though.

 

[wdavidhicks]

From when that pic was taken it wasn't impressive, performance-wise. All the mods were "show" and "durability". Alum bulkheads, chassis rails, arms, MIP cvds, Proline steering kit, Associated shocks, heat sink (cuz I stripped the stock one).

Here's a pic with the lid off.

Now it's time for the "go" stuff.

And thanks, Whitt!

 

[Error401]

Let me rephrase my last post, Very nice ride! Even though I'm a Savage driver, I still like a trick ride. I followed the same philosophy. I'm running cvd's all round, HB metal brake disk, GPM metal brake hub, HB pipe, GPM tank guard, covered coils and stacked springs, replaced servos and a hump pack, better rims, motor saver filter, and the picco. I bash pretty hard, so I'm not into the aluminum arms or towers & such. But to each his own I guess.

Whitt...

 

[wdavidhicks]

If I'd been on this board longer before I broke my first a-arm I probably would have bought RPM. So if I break one of these I'll probably have seven alum arms for sale.

I keep hearing the term "hump-pack" not necessarily referring to electric vehicles. Is that just replacing the four alkaline cells in the holder with five 1.2 volt NiCd or NiMH batteries? This is a weight advantage?

I did replace the steering servo with a HiTec 645MG.

 

[Error401]

Spot on Dave, but the NiMH cells are 2/3AA, so the weight is roughly the same, and the hump fits in the same space as the dry cell holder. The packs I'm running are 1100mAh and are generally good of an afternoon. The main advantage to the hump are they save money in the long run on batteries.

 

[imnotsure]

I called nitro house today and asked about the myth of the silver & black LSN the silver will run colder and slower on the power band. And the black is faster and hotter. They will both work just different power bands.

 

[Error401]

Hmmm. I looked at the needle again last night and the way it tapers makes the midrange rich, so that the low speed and WOT mixes are right, but it slobbers at 1/2 throttle. That sux. I want an even, dead on mix from idle to WOT, not some BS juju voodoo mix that acts funny on one spot. Looking at the 21BB carb, you can see that the needle opens in a more proportional way than the picco carb. Sorry, had to vent, still haven't gotten to try the new carb yet today, and the anticipation is killin me. Thanks for checking with nitrohouse anyway.