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Old 10-12-2008, 11:01 AM   #346
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thanks a bunch!
ill give it another go and report back.
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Old 10-13-2008, 06:08 AM   #347
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Picco's can leak from the carb body causing the idle to hang up.... very common Picco issue....
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Old 10-13-2008, 06:16 AM   #348
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Pay attention to "Kurly" he is a very good IDM engine tuner.
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Old 10-13-2008, 09:49 AM   #349
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ahhg..still no goodi have tuned so many engines but this is kicking my butt.
i have the lsn out at 1.43mm and the idle opening about 0.60mm,
hsn out 5-5-1/4(about flush).
at these settings its running really rich/bubbly at idle,can barely do a pinch test,if i increase the idle screw or lean the lsn its better but when i blip the throttle it will hang again when carb barrel closes,its like the lsn tip is getting stuck in the housing (where it slides in and out)
im using the idm t7 turbo plug and byrons gen/2 20% with the sirio 2013 pipe.
i also had the lsn out about 0.75-1mm and was much better but still hanging but only intermittantly,just seems like at a low idle it will not hang but as soon as i increase the idle screw to where it stays idling then blip the throttle it will hang again.
what ever it is it has to be in the bottom end tuning,at 3/4 to full throttle its great..engine has no vacuum/air leaks or oil seapage from bearings,new fuel lines,tank holds pressure etc.the carb neck and backplate have been sealed.
just dont know?
if some one has the same exac engine i could try there needle settings and go from there.
.21 IDM On Road Motor P7-R .21 EVO 3 SG
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Old 10-13-2008, 10:16 AM   #350
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i have used a strip os masking tape just to show the seam that needs to be sealed.this is a very common leak area for Picco engines...the seam between the composite and metal is prone to leak once the carb metals become heat soaked... the symptom is identical to what you are describing.....use JB weld,Lucky7,1211 or any other type of sealant to cover this seam

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Old 10-13-2008, 10:34 AM   #351
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maximo thanks,as soon as it cools down a bit i will do that,tried everything else what can it hurt.
ill get back and keep yas posted.

ok i have it curing now,in the mean time i talked to the guy at ofna and he said the needles should be Flush on the high speed needle and 1 turn out from flush on the low speed.
dont understand because everyone is saying 2-3mm out on the lowside?

Last edited by helivaguy; 10-13-2008 at 11:35 AM.
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Old 10-13-2008, 06:17 PM   #352
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Quote:
Originally Posted by Maximo View Post
i have used a strip os masking tape just to show the seam that needs to be sealed.this is a very common leak area for Picco engines...the seam between the composite and metal is prone to leak once the carb metals become heat soaked... the symptom is identical to what you are describing.....use JB weld,Lucky7,1211 or any other type of sealant to cover this seam

I have to say that this is not a common problem with the carb's. Yes it does happen but not so many now. Most of the time you can check this by removing the carb. sealing both ends with finger and then go ahead and install fuel tubing on the inlet fitting. blow in and let the slide move out run light oil over the seams and check for leaks. Also please follow what Kurly has to say he is one of my best motor guys with engines and knows the way around the carb. If you have a leaking carb then you can send it back for warranty. I do not know what country you are in but I have never had a issue with replacing a new carb that is bad.
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Old 10-13-2008, 08:43 PM   #353
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I have to say that this is not a common problem with the carb's. Yes it does happen but not so many now. Most of the time you can check this by removing the carb. sealing both ends with finger and then go ahead and install fuel tubing on the inlet fitting. blow in and let the slide move out run light oil over the seams and check for leaks. Also please follow what Kurly has to say he is one of my best motor guys with engines and knows the way around the carb. If you have a leaking carb then you can send it back for warranty. I do not know what country you are in but I have never had a issue with replacing a new carb that is bad.


much of the time it will not leak cold, it only leaks when the metal components of the carb get heat soaked.. You will find the hotter the motors get the more prone they are to this leak... As well its not uncommon for this leak to appear later in a engines life, sometimes they will run awesome for the first 3 or 4 gallons, then slowly they will develop a tendency to run on after a high speed pass...in offroad racing this can be a major PITA...... Sealing this area of the carb is very simple, lately I have been using Lucky7 sealant and things are working awesome.....Another area I have seen issues is with the idle screw leaking, I use teflon thread sealant for that one.......
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Old 10-14-2008, 05:55 AM   #354
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it did have a slight bubbling at the seams but not sure if its enough to cause the issues i am having,i went ahead and sealed the seams with military grade epoxy last night and will try it this morning.
again this engine is still relitively new and fresh most of the fuel that has been through it is from trying to get it tuned,i learned even the previous owner had tuning issues with it so its not just me.
i have had offroad piccos in the past but never had a tuning issue like this one.
will keep you posted.
thanks again all

update:
no change-still having same idling issues,idle still hangs weather the lsn is 1 turn out or even out to 2-3mm from ballend,i can stop the hanging if i lower the idle screw but when i blip the throttle it starts to hang again.
at only 1 turn out its much better wont hang as much but at 2mm out it wont even idle sound like its gurgling/flooding or 4 stroking and even will still hang so not even sure if its a rich/lean condition or something else.

Last edited by helivaguy; 10-14-2008 at 07:44 AM.
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Old 10-14-2008, 09:00 AM   #355
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Quote:
Originally Posted by helivaguy View Post
it did have a slight bubbling at the seams but not sure if its enough to cause the issues i am having,i went ahead and sealed the seams with military grade epoxy last night and will try it this morning.
again this engine is still relitively new and fresh most of the fuel that has been through it is from trying to get it tuned,i learned even the previous owner had tuning issues with it so its not just me.
i have had offroad piccos in the past but never had a tuning issue like this one.
will keep you posted.
thanks again all

update:
no change-still having same idling issues,idle still hangs weather the lsn is 1 turn out or even out to 2-3mm from ballend,i can stop the hanging if i lower the idle screw but when i blip the throttle it starts to hang again.
at only 1 turn out its much better wont hang as much but at 2mm out it wont even idle sound like its gurgling/flooding or 4 stroking and even will still hang so not even sure if its a rich/lean condition or something else.

they can also suck air from the idle screw......use some teflon thread paste to seal the threads.....
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Old 10-14-2008, 09:07 AM   #356
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Question.
Does an IDM engine come with the carb fully installed?, or do you have to install it yourself?

Because then it might just be, that with installation of the carb mounting screws, the rubber seals on these screws are damaged...
You really have to oil them, before pressing them in the engine case.....
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Old 10-14-2008, 09:45 AM   #357
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i teflon taped all 3 needle threads(hsn-lsn-idle screw) and oiled all the o-rings,the carbneck,backplate, and carbneck pinch assembly have also been sealed,all the composite to aluminum seams have been epoxied on the carb.
no change same issues, just cant be in the tuning because the previous owner i bought it from had the same problems (he never told me)who happens to be a pro 1/8 onroad racer.
these needle have been turned every which way a thousand times and its always the same thing.
i have no choice but to pull it out, i just cant do anything else with it.
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Old 10-14-2008, 11:21 AM   #358
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Quote:
Originally Posted by helivaguy View Post
i teflon taped all 3 needle threads(hsn-lsn-idle screw) and oiled all the o-rings,the carbneck,backplate, and carbneck pinch assembly have also been sealed,all the composite to aluminum seams have been epoxied on the carb.
no change same issues, just cant be in the tuning because the previous owner i bought it from had the same problems (he never told me)who happens to be a pro 1/8 onroad racer.
these needle have been turned every which way a thousand times and its always the same thing.
i have no choice but to pull it out, i just cant do anything else with it.
front bearing or perforated case ? man that must be frustrating, i feel for you bro !
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Old 10-14-2008, 11:43 AM   #359
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thanks man,
just dont think i want to invest any more time or money in this thing,
its a shame because this thing is still relitively new and already had a carb replacement from previous owner so it was a factory lemon from the begining,dont know man..this idm picco left a bad taste in my mouth.
guess ill have to use it as a paperweight now.
thanks again for all yours and everyone elses help.
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Old 10-14-2008, 12:20 PM   #360
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Check your pipe for any blockage. I spent two days at a race this summer trying to get the motor to stay running. I finally went to another motor and it did the same thing. I changed the pipe and every thing was great.
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