engine trouble

[beefymcman]

hello i have a torq .16 sitting on a maximum st. and the engine runs but it likes to die when it feels like it but when it does run it runs fine

[scoobie]

When does it die (or flame out)? When youre accelerating, decelerating, idleing, on rough landings...?

How much fuel has the motor seen?

How long does it run before it flames out?

What heat range is your plug?

Does it eat plugs?

Answer these questions and be as descriptive as possible...

[beefymcman]

it dies on both the accelration and deaceleration (spelling)
For fuel i have bought it used so i have no clue i have only put about a takn and a half or so because it's been having the problems it has a new crank piston and sleeve and they have been broken in
It doesnt eat plugs the plug is brand new
the plugs i am using are duratrax silver sport with TQ 20% fuel
we had it runnign great but then the crakn shaft snap[ped in two because of a crash and now it isnt running very good at all when u give it half and then jump up to full it boags down but keeps going it has no specific dieng pattern

[scoobie]

You might be running the wrong heat range plug, if its a HOT plug, you should be ok.

So you have broken the crank previously? Hmmmm.......

It might be a main bearing...If you broke a crank, the main bearing took a helluva beating. If you take your motor apart, put your finger on the main bearing and rotate it, if it feels gritty, its bad and could be the source of your problem.

Also, if a crash is what broke the crank, you could have a cracked block....

Check your clutch too, if something is wrong there, it could lead to a ton of gremlins...

[beefymcman]

all that was fine it cracked were the flywheel and the clutch in that area

[beefymcman]

stil cant figure it out:cussing:

[scoobie]

Have you tested for airleaks?

[beefymcman]

i think there is a leak in the line but air leaks give me a few places to check in case i forget one

[scoobie]

Heres a good post from Kaos Ill use to save myself a little time...lots of good stuff...

Sometimes, a nitro engine will play mind games with you, and that can make your nitro experience a bad one. And the more frustrated you get when your engine isn’t running properly, the worse the situation will get. You may get to the point at which you think you’ll never get that engine running, and that’s why we’re here. These 5 engine problems tweaked my noodle a few times, and after a lot of thinking and a few choice words, I solved them. Engines are relatively simple, and only a limited number of things can go wrong. With these 5 problems solved, you shouldn’t have any trouble getting your engine to run.

1. ENGINE DOESN'T START
If your engine ran fine and now doesn’t even start, chances are, your glow plug is fouled or your Ni-starter has lost its charge. I grab the Ni-starter and stick a plug that I know is good into the end of the starter to see whether it glows properly. If it doesn’t, I know I have to charge or replace the starter battery. If that plug glows, I know that the one in my engine is shot. Your engine may not start after it has been running; in this case, the engine might be too hot to ignite the fuel entering the combustion chamber because of the temporary loss of compression and the fuel vaporizing in the carb. Let the engine cool for a while before you try to restart it.

2. ENGINE IDLES ERRATICALLY
If you’ve had to adjust the low-speed needle and the idle screw a million times, you probably have an air leak. It may be in the engine or the fuel system. Check your empty fuel tank by attaching fuel tubing to the pressure fitting and to the fuel fitting and then submerging it in water. Now pinch one of the fuel lines to pressurize the tank with air, and then blow into the other line. Do you see air bubbles coming out of the tank? If you do, identify where they’re coming from and either replace the tank or seal the leak with silicone. The fuel tubing itself can leak, and finding a hole in a piece of fuel tubing can be a pain, so replace the tubing. A fuel filter may also leak air; remove the filter from your vehicle and make sure that the parts are screwed together tightly and that the O-ring is intact. Last, but not least, your air leak may be somewhere in the engine. Instead of trying to find out where the leak is, just take the engine apart and seal every joint with oxygen-safe gasket sealant. Seal the backplate, the carb and all the joints on the high-speed needle. Check all the O-rings and replace any that look worn.

3. ENGINE RUNS ON THE STARTER BOX BUT DIES WHEN THE VEHICLE HITS THE GROUND OR WHEN YOU HIT THE BRAKES
You have a problem with your clutch. Some part of it is hanging up and causing the engine to spin the cutch bell at idle when it is not making a lot of power. It has enough power to turn the wheels when they are off the ground, but as soon as you stop them from turning in any way, the engine dies. Try rotating the clutch bell while the engine is off and the brake is disengaged. If it doesn’t turn freely, you have a problem. Pull the engine out of your vehicle, disassemble it and inspect every part of the clutch assembly. As you take parts off the engine, check to make sure that they are not broken or worn. Replace parts that you think should be replaced, but if everything checks out, see whether the clutch-bell bearings rotate freely. If the clutch bell doesn’t rotate, replace the bearings. Before you reassemble the clutch, lightly scuff the clutch shoes and the clutch bell with fine sandpaper and clean them with motor spray.

4. ENGINE BOGS DURING THE TRANSITION FROM IDLE TO FULL THROTTLE
First, check the low-speed needle to see whether it’s adjusted properly. Drive the vehicle around for a few seconds to clean out the engine, and then bring the vehicle over and pinch the fuel tubing while the engine is at idle. After a second or two, engine rpm should slowly rise and the engine should shut down. If the engine dies right away, your low-speed needle is set too lean, and if it takes longer than a second or two do anything, it’s set too rich. A setting that’s too rich or too lean will make the engine bog slightly when you get on the throttle. If altering the needle setting doesn’t solve the problem, use a “hotter” glow plug. The fuel may be cooling your existing plug and making it hard for it to ignite the fuel in the combustion chamber

5. ENGINE SUDDENLY LOSES POWER
Chances are, your air filter is too dirty or your tuned pipe is clogged. If you have either of these problems, you can lean your high-speed needle all you want and your engine’s performance won’t improve because there’s a lack of air or exhaust flow through it. Clean your air filter, relube it with any air-filter lube and you’ll be good to go. If your exhaust is clogged, you’ll have to remove the exhaust pipe and clean it. If your stinger is clogged, pick out the debris while its end is facing downwards so that the debris falls out; if it’s clogged inside, try blowing the debris out with compressed air. Blow the air into the stinger so that the debris can easily flow out through the inlet side of the pipe.
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[beefymcman]

none of it were the symptoms HMM

[scoobie]

In #2 it explains how to test the easiest parts of the system for leaks....the rest of the info is just good to know.

Also, you didnt say what heat range your plug is. Make sure you have a hot plug in there...its critical.

Now that I have a couple minutes...testing the engine for airleaks.

If your car isnt clean, clean your engine around the backplate, carb neck etc with some nitro cleaner and a soft bristled brush. Then clean off the top of the tank and fuel fiters etc. You dont want any dirt getting sucked into the engine...

Get some WD40, get the engine running on a stand, let it get a little warm, then in SHORT BURSTS, spray the WD around the backplate, the carb neck and head. If there is a airleak the engine will bog when you spray the leaky spot. Then, like described in tip #2 above, take the motor apart as needed and seal up the leaks.

Another way to spot a leak, is after a run with a semi clean car, look at the car and look for oily dirt spots on the engine, or anywhere else in the fuel system...like the fuel filter.

Keep us posted, Good luck!!!

[beefymcman]

hey man i found the problem missing carb screw :eek:

and i cleaned the carb man was it dirty i gotta set everything back to stock but the idle screw and all that good stuff is going to be a pain

[beefymcman]

need to order the part then readjust everything then see how she runs i think i need a new tank to and lines because thers always bubbles in the line

[beefymcman]

hey guys i got everyhting adjusted and cleaned man it runs like anew engine now it was on wet pavement man it wouldnt stop burning and drifting fun because i didnt wear down my tires

[beefymcman]

today i had a problem two of the engine mount scres came off making the enginge come loose and making the clutch move wich rubed the spur gear and one tooth snapped im gonan try running it and see if it affects it. i locktighted all the screws but one mount hole was dtriepped
so ya kinda a bad day

Also i was running it and the glow plug popped out of the head the threads were fine nothing wrong i mean i lost it totaly

[AZRCaddict]

Make sure you use loctite on your engine mount screws. On my Mayhem that would happen all the time and I would chew a clutch bell and my spure was chewed like this " \ ". I didnt replace the spur and only the bell and it kept chewing bells because of the spur so I would replace both.

And the glow plug, make sure you tighten it down as much as you can.

[beefymcman]

ya i did all that im keeping the spur for now the clutch bell is fine but the only problem is the spur has a one tooth missing so i orderd another but im going to run it like a day with it missing a tooth

[beefymcman]

it runs fine does any one have a good 20% fuel thats good because i need some more and a good hot glow plug

[scoobie]

Any hot plug should work. The Odonnell OD77 is a good one, and they have long and short versions. You need to make sure you get the right length plug as well. Dont know which one your motor takes, so find out.

When the motor is warm, cinch down the plug to seat it fully. Just a little turn (1/12 of a turn or so) is all it needs

As far as fuel, everyone has their favorite flavor. Get whatever your LHS has that they can get consistantly. As long as you stick with a good brand, like Sidewinder, Odonnell, Blue Thunder, etc youll be ok. Just be aware, when you switch fuels, youll need to tweak the carb a little to get the perfect tune

[beefymcman]

well my local place isnt very good i usually order off line but shipping right now im using TQ but my local place charges around 15 or so a quart