KID_EVIL!

My fuel tank seems to have an air leak at the lid. I was just wondering how or how much this effects the way the truck runs. Would it make the truck run real boggy?

Argess

An air leak like that keeps the fuel tank from pressurizing fully. Therefore, you should notice the engine leaning more as the fuel level drops. Gravity pressure is very small compared to tank pressure, but if you have an air leak, this no longer is so. A constantly changing tune is the symptom. Not so much at idle, but at higher rpms, especially at WOT.

BudBud

It will do that, the bad part is the lean conditions the air in the fuel causes. Did I send you a bad tank? Surely the warranty is up by now. [8D] Glen

KID_EVIL!

So would that explain why it is "so out of tune" now? my brother had it rocking the day we (he) tuned it in. But the next time I had it out, it was running real boggy and I can't seem to get it going again........ New tank??

BudBud

Temperatures and humidty really affect these little engines, you almost have to tune a little every time out.

KID_EVIL!

oh I know you need to do a little tuning each time. But it's way off right now. just wondering if the tank is my major problem

supertib

please describe exactly what it is doing, chances are you guys have over tuned the needles before you let the motor warm up fully...........FYI a Picco needs to be warmed up 100% before its ready to tune, the warmer they get the leaner they will run....so if you start it cold and it seems pig rich and you attempt to lean it down to a perfect tune when cold, the tune is going to get extremely lean as soon as the carb gets heat soaked..... THe key with a Picco is to run them rich till they warm up, the motor will usually come into its sweet spot once the carb gets heat soaked........ As well when you tune a Picco you only use tiny nudges of the needles, you never ever ever make large adjustments, many times people start bottoming out their needles counting turns and end up screwing up royally....If it was tuned right before chances are it only needed a nudge from that position...

As a general rule your HSN should be slightly in from flush, and your LSN slightly out from flush, less then 1 mm...as well idle gap between .5-.7 mm, also avoid any type of inline fuel filter

KID_EVIL!

Ok supertib heres some detail.

It starts up fine and idles without any problems. When my brother tuned it for me he warmed it up and tuned it as it is supposed to be tuned. We noticed that when you blow in the fuel line at the exhaust the air comes out of the tank lid.

When I drive the truck it only goes maybe 10 mph. yesterday I had it out. it was only getting up to about 130 degrees and bogging like I said. I would turn the HSN slightly richer (1/8 turn) and no differance. Slightly leaner and it would bog a little more.

I mean I can get my brother back over here, but it's just a pain when I have to call him over all the time. If I can get to understand more *** i'm doing I'll be ok. I just don't want to mess around to the point that I end up trashing this motor. I'm no mechanic.

Obviously the tank has to be delt with. I am just wondering if the air leak is what is driving me to drink the nitro fuel instead of burning it Lol.

supertib

Do you have a video camera ? if not you can call me when your running your truck and I can guide over the phone on what to do..... it is possible you have damaged your glowplug....

NitroVenom

Even your tune was extremly off, you should be able to go more then 10 mph. Are you sure your getting full throttle?

nitrofreak6071208

i dont know what kind of truck you are talking about but my nitro 4 tec had teh same prob, so opened up the lid to the gas tank and theres a little screw at the underside of the lid i lossend it up a bit and it sealed my prob

supertib

you can also use a rubber band around the tank to tighten down the lid

BudBud

He has a Savage XL with a Picco 28 and that engine is an animal!

His engine in a stock [link=http://www.youtube.com/watch?v=c3VAeFc7_uw]chassis.[/link] He truck running [link=http://www.youtube.com/watch?v=RZ_QuBQ68TE]both power and high speed.[/link] I sent that truck to him and it is an animal.... as you can see. I had already been through all the carburetor and engine sealing, it should be good for several gallons, it was just getting enough time on it to come into its power.

So, he has an air eak in his fuel system or as Tib said, a dying plug, or probably a tunning issue...

[link=http://www.youtube.com/watch?v=oSmMzpZM_As]A great tuning video![/link]

[link=http://www.youtube.com/watch?v=BJFsJAxNoRg&feature=related]Tuning... round two...[/link] .... Glen

twobnvd

My Feedback: (1)

Not trying to over post anyone but I have gone through three tanks that is exactly how mine acted when there was a pressure leak in the tank. Could be other things but that is EXACTLY how mine was acting when the tank had a small crack in it or if the line to the exauhst came loose. Idles fine but hard on the throttle boggs down. Good luck man. If adjusting it doesnt fix it it has to be some type of air leak keeping it unpredictable. ALso once my head screws came loose causing a similair type of issue not exactly the same but close..

rclugnut10

My Feedback: (1)

when i'm dumping my tank, blowing thru the pressure line, once it get past that step i can hear a small bit of air esaping, your o-ring may also be loose, or the holder that keeps it on, mine fell off once... if you have a second feul tank check for any differances in the seal area or a black thing in your feul tank... but i don't think it'ld cause that big of a differance...

the lug