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Old 03-25-2008, 01:44 PM   #1306
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Trust me mate..I am doing nothing wrong LOL !!!!! You never know who you are dealing with on the internet, but I can assure you I am more then qualified to diagnose a leaky carb body !!! I have many customers running modified Picco's and we have had to seal the bodies of a pretty high number of Picco carbs.... The difference between sealed and un-sealed is dramatic to say the least...

Now its still winter where I live..but within the next 4 weeks I hopefully will be able to run some nitro...When I do I will make a video of what these Picco's run like before and after I seal the carb body... I think a few of you are going to be eating some Crow on this one !!!!
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Old 03-25-2008, 02:54 PM   #1307
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Picco carbs leak guys !!!!!!! Out of 10 Picco's your going to find 3 with a split carb body that will leak and not tune...... This has been an issue with Picco for years and years..... Nobody has been quick enough to catch it tho !!!!! The seam between the composite carb body and the metal end bell is prone to leaking..you need to seal this seem with JB weld or sealant of some kind......... every Picco any of us run has this seem sealed and all our Picco's tune as easy as any other motor............ If you dont seal this seam the motors can be difficult to tune, as the airleak acts much like a Phantom leak..it will only become apparent when the motors gets fully heat soaked,,,,,,you will chase a tune forever till you seal this seem !!
I would have to say this seems to be true. I presently have 2 picco's (3rd on the way, right Sam? ) and I also was having this same problem. One motor would work perfect and with the other motor, it seems I am always chasing a good tune. Around the base of the carb, would always seem damp. I checked the fuel line everything......

Yesterday I was doing some testing with the "leaky" motor, which funny enough runs better, and I got the motor tuned perfect!! Then just like that the motor starts "hunting". I then did a WOT when the carb shot right out from the base of the motor with only the fuel tube holding it in place.

Now, I know you guys are thinking I did not seat the carb and tighten the bolt properly, but this was not the case. Carb was seated perfectly and the bolt was so tight it could not move anymore.

I don't know if the slide cams that hold the carb in place is worn, but they seem perfect. Anyway, I love my JL so much that I did exactly what was mentioned. I changed the carb seal, seat the carb again, tightened the bolt and sealed it to the block. I did this only last night.

I am happy to see I am not the only with this issue.

All in all, I would still buy a JL anyday.
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Old 03-25-2008, 03:03 PM   #1308
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A few guys last summer were having trouble with the carb pinch bolts bottoming out on each other, before they pinched the carb fully, it would feel tight when cold, but when warmed, the carb would fall out. The solution for this is to take the pinch bolts halves out and take a little material off the face or front of each one, in other words where they meet together in the block, this will fix that problem.
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Old 03-25-2008, 03:06 PM   #1309
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I would have to say this seems to be true. I presently have 2 picco's (3rd on the way, right Sam? ) and I also was having this same problem. One motor would work perfect and with the other motor, it seems I am always chasing a good tune. Around the base of the carb, would always seem damp. I checked the fuel line everything......

Yesterday I was doing some testing with the "leaky" motor, which funny enough runs better, and I got the motor tuned perfect!! Then just like that the motor starts "hunting". I then did a WOT when the carb shot right out from the base of the motor with only the fuel tube holding it in place.

Now, I know you guys are thinking I did not seat the carb and tighten the bolt properly, but this was not the case. Carb was seated perfectly and the bolt was so tight it could not move anymore.

I don't know if the slide cams that hold the carb in place is worn, but they seem perfect. Anyway, I love my JL so much that I did exactly what was mentioned. I changed the carb seal, seat the carb again, tightened the bolt and sealed it to the block. I did this only last night.

I am happy to see I am not the only with this issue.

All in all, I would still buy a JL anyday.
Meaning you never did it correctly the first time, Neal is talking about leaking from the body itself, and you are talking about it leaking thru the base seal, that is 2 different leaks.
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Old 03-25-2008, 03:43 PM   #1310
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I have seen this in both .21 and .28 carbs.... from the Drake version,Jammin version, As well as the Trinity Wasp Pro engines...... pretty much hit and miss, some will leak some will not... work with 20 of these motors and you will see a definite pattern....

Here is the problem area..I have wrapped a piece of tape around the seam to simulate the bead of sealant...But by no means is the tape the solution... I suggest a bead of JB weld around the seam of the carb.

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Old 03-25-2008, 03:49 PM   #1311
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Hey Neal,
I know who I am dealing with, Trust me
So we know each others names, that still doesn't change a thing.... I still say I know these Picco carbs very well, and without question this is a huge problem area for many Picco engines.....very easy fix regardless !

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Old 03-25-2008, 03:52 PM   #1312
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I would have to say this seems to be true. I presently have 2 picco's (3rd on the way, right Sam? ) and I also was having this same problem. One motor would work perfect and with the other motor, it seems I am always chasing a good tune. Around the base of the carb, would always seem damp. I checked the fuel line everything......

Yesterday I was doing some testing with the "leaky" motor, which funny enough runs better, and I got the motor tuned perfect!! Then just like that the motor starts "hunting". I then did a WOT when the carb shot right out from the base of the motor with only the fuel tube holding it in place.

Now, I know you guys are thinking I did not seat the carb and tighten the bolt properly, but this was not the case. Carb was seated perfectly and the bolt was so tight it could not move anymore.

I don't know if the slide cams that hold the carb in place is worn, but they seem perfect. Anyway, I love my JL so much that I did exactly what was mentioned. I changed the carb seal, seat the carb again, tightened the bolt and sealed it to the block. I did this only last night.

I am happy to see I am not the only with this issue.

All in all, I would still buy a JL anyday.


Sounds like you need to shorten up your cinch rods...they are bottoming out before they clamp the carb tight enough..... take some fine grit paper and sand down the two opposing ends of the cinch....it only takes a little sanding and you will get a much stronger clamp.. This is an issue from time to time with engines, you will see this on many different brands....
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Old 03-25-2008, 04:09 PM   #1313
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Do OS TZ carbs fit these engines?? i have a spare carb sitting at home.
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Old 03-25-2008, 05:09 PM   #1314
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Thanks Maximo & Ffejdat for the suggestion. Will do this.

As for the OS carb, sorry it won't fit.
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Old 03-25-2008, 05:58 PM   #1315
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I have only had one carb leak from the area shown in the picture. My biggest problem has been with the carbs working themself loose from the case.

BTW: Novarossi carburetors fit
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Old 03-25-2008, 07:02 PM   #1316
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I have only had one carb leak from the area shown in the picture. My biggest problem has been with the carbs working themself loose from the case.

BTW: Novarossi carburetors fit
Do they??? I have seen one trying to be fitted and the rods that support the carburator had to be filled down with a dremel so it would grab the carburator like it should. But I think this was on a IDM engine, so I cant be sure its the same with the JL... Can anyone shed some light on this???
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Old 03-25-2008, 07:58 PM   #1317
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Do they??? I have seen one trying to be fitted and the rods that support the carburator had to be filled down with a dremel so it would grab the carburator like it should. But I think this was on a IDM engine, so I cant be sure its the same with the JL... Can anyone shed some light on this???

Fits on the JL with no mods. I only wonder if the composite carb provides a more consistant tune as oppose to the aluminum carb. Does anyone know?
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Old 03-25-2008, 08:01 PM   #1318
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Do they??? I have seen one trying to be fitted and the rods that support the carburator had to be filled down with a dremel so it would grab the carburator like it should. But I think this was on a IDM engine, so I cant be sure its the same with the JL... Can anyone shed some light on this???

I run the IDM engines. I have run it with a Nova carb and I didn't have to dremel anything.
The idea behind a composite carb is that it will not get as hot as an aluminum carb. This will help keep the mixture cooler and help prevent vapor lock.
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Old 03-25-2008, 08:08 PM   #1319
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I run the IDM engines. I have run it with a Nova carb and I didn't have to dremel anything.
The idea behind a composite carb is that it will not get as hot as an aluminum carb. This will help keep the mixture cooler and help prevent vapor lock.

Ok, so this is why OS places an insulator on their carbs as well. I did find the the Nova carb stays put because the barrel is aluminum as oppose to the JL which is steel.

Scott, did you notice any performance increase using the Nova carb?
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Old 03-25-2008, 08:17 PM   #1320
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I wonder as well since the Nova carb is taller if it would actually provide the motor with even more torque, since this is what you would do with a natrally aspirated engine. Add "trumpets" over the carb to increase low end torque.

Hummm.... if the same theory applies???
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