Well i am a noob at nitro so i knew i was gonna have some problems. Well the problem im having now is that after about 2-5 minutes of run time my jatos engine just shuts off. Its hard enough to start when i take it back out for a run when its been put on the shelf for only a day. I have to prime the engine for ages. Its bugging me that my engine dies after only 2-5 mins and is sometimes really hard to start and sometimes starts right away. My engine is tuned sorta in the middle of the rich and lean. I dont really know what im doing when its comes to tuning though. Any help?

um i think u might have an airleak somewhere either the fuel lines, fuel tank or the engine like the front bearing or head

How would i tell i have an airleak?

well u can replace the fuel lines, with the tank put the tank in a tank of water and seal the lid and seal the other pressure line, then submerse the tank in water and blow in one of the lines with the other sealed and if any bubbles come out then there is a leak in the tank

Main needle may have debris stuck inside. Are you using an in-line filter?

What is the main needle and what is an in line-filter?

It is a filter you put in the fuel line. There are many types but here is one to give you and idea.
http://www2.towerhobbies.com/cgi-bin...&I=LXK134&P=ML

if it's running and shutting off, that's because it's getting hot. how much fuel have you run through the engine? Since you're new to nitro, if you've even only run a half gallon you might have toasted your engine.

worst case scenario

I hope i didnt toast my engine. I have only ran about 10 tanks through it and i broke it in on how the dvd showed me to do it.
So im assuming i have a leak in my tank or fuel line? Im going to do the fuel tank leak test soon.

Also smoke comes from the head of the engine. No glow plugs have burnt out yet though.

loosen all the screws on your head, then tighten them snugly in an X pattern (like what you do when you're putting a tire on a real car)

Ok well i took my jato out today and it ran better. I dont think its an air leak actually but i think it is just getting too hot and stopping because of that. I think this because when the engine shuts off i wait about 1 min and its easy to start up again. What do you think?

mmmmmm musta just been to hot then. make sure that it runs at a reasonable heat and try and keep it around there.

Yeap i did the tank test and there is no leaks. I learnt how to remove a tank the hard way though. I pulled the fuel line of the caruberater and fuel bursted into my eyes. It wasnt fun washing it out at all. I hope i dont go blind. Anyways how do i find a good way to keep the heat reasonable? I really want my jato to run well. Also on a very well tuned truck how many times will the engine shut off during one tank? I assume it doesnt at all?

probably running too lean then. fatten the HSN up about a half turn and tune from there

The easy way to tell how hot your engine is running is to use a temp gun. Cheap and effective.
Another way to get an idea is to drip a couple of drops of water on the cooling head...If it sizzles and bubbles and evaporates in 3-5 seconds, then it's about right.
If it beads up and jumps off, or evaporates instantly, then it's hot.
There should always be a 'healthy' trail of smoke from the stinger.(depending on which fuel...some smoke more)
---Even at WOT there should be smoke---

also if you are running with your body on make sure you have some airflow vents to allow air to get to the engine for cooling ie open the windscreen on the motor side to allow air in and any other vent looking areas that are around your engine

The Jato has a 'roof vent' that could be opened up for more air flow, too. I would recommend that around all cuts in the body you re-inforce the area with shoe goo, or goop. And try to round off the corners of your cuts. Corners are more prone to cracking than curves.

A good running, well tuned engine will run for many tanks without flaming out(shutting off).
Obviously that doesn't take into consideration running out of fuel from 'resting it's wheels' on it's roof. Also it's a tricky operation to refuel a running RC by yourself with the body on. When you run your engine with a pressure line from the exhaust to the tank to pressurize it, then open the lid to dump more fuel in, the resulting drop in fuel pressure is usually enough to kill an idling engine. If you have enough hands, you can blip the throttle to keep it running, while holding it still, while holding the tank lid open, while holding the fuel bottle...

Another thing to consider is the crank bearings. I know the older 2.5s were famous for leaky bearings, if you are still convinced of an air leak.