xtm xt2 problem
 

Hi I am totally new to rc cars went out and got my first one yesterday andI have had nothing but problems. When I manage to get it started It's ok until Igive it full throttle then it dies. Like I say I don't know my ar$e from my elbow asfar as these go, so any help will be much appriciated.

Thanx</p>

RE: xtm xt2 problem
 

Welcome.

OK, first of all, if it's brand new, DON'T give it full throttle. Tell me if you have broken the engine in yet using heat cycle or other method?

RE: xtm xt2 problem
 

hi i dont full on give it full throttle for any length of time just a small kcik here and there. what do you mean about heat cycle method? the bloke in the shop said all i have to do is run it on half throttle for 4 tanks of fuel?

RE: xtm xt2 problem
 

Nice 'bloke'.

The engine that comes in that car is pretty robust, however, it's probably set pretty rich at the moment. Rich is good for a new engine.

Here's how I break all my engines in:

Tank 1: Get engine started. run the car in figure eights or just up and down the area you are using. give it just enough throttle (about 1/8 - 1/4 squeeze) to get it moving a bit. Squeeze the trigger each time for about 3 - 4 seconds, let off the throttle then count to 10, squeeze again for 3 - 4 seconds, let off the throttle then count to 10, repeat until tank is empty and engine dies.

Now here's an important part. Every time that engine turns off, reach under the car and move the fly wheel until your piston is bottom dead center or BDC.

Allow the engine to cool for 10 minutes.

Tank 2: Fill the tank and get the engine started, again, figure eights or just up and down the stretch you're using. This time repeat the above process, but squeeze the trigger for about 5 - 6 seconds each time, off the throttle for a count of 10 and repeat till the tank is empty.

Important part again. Every time that engine turns off, reach under the car and move the fly wheel until your piston is bottom dead center or BDC.

Allow the engine to cool for 10 minutes.

Repeat this process for 6 tanks in total. Each new tank, add a couple more seconds of throttle time and a little harder squeezes up to half or just over half throttle.

Once that's done, your engine is broken in and you're pretty good to go. I continue to run my new engines on the rich side of the tune until they've gone through at least 1 gallon of fuel.

If you're engine will not stay running while doing this break in, turn your high speed needle clockwise in 1 hour (just like the face of a clock) incriments at a time until it will stay running.

Breaking a new engine in can at times be a real PITA, we know, we've all been there. But keep it as rich as possible as you want as much oil going through that engine as you can through break in. Also, if you can possibly heat the engine up with a heat gun or good blow dryer before trying to start it, that helps a good deal.

Google and youtube search this phrase: breaking in your rc engine

Plenty of tutorials floating around in web land mate.

There are other methods people use to break in their engines, but this is my preferred choice.

Let us know how you get on mate and good luck.

RE: xtm xt2 problem
 

thanx for that mate, give me a lil while to get my head around it and i will report back. i havent been doing anything like what u said, i reeealllly hope i havent caused any damage. i spent every penny i had on ithttp://www.rcuniverse.com/forum/js/f.../cry_smile.gif

RE: xtm xt2 problem
 

It should be ok. You say it does fire up.

A couple of other things. During the break in, you will be going through a lot of fuel because it's so rich. You want a good amount of smoke coming out the pipe 'stinger' and you'll also notice quite a bit of fuel/oil spitting from the pipe as well. This is good. Don't worry about that.

Tuning a nitro engine can seem like Harry Potter stuff, but it's not that hard.

At all times, you want a nice stream of blueish/grey smoke coming from the pipe.

After your engine is broken in, set to tuning it.

Never try to tune a cold engine though. Get it up to a nice operating temperature then start tuning.

Here's what I do:

Once engine is at temp, pinch the fuel line shut about 1 inch from where it meets the carb. Ideally, the engine should rev up and die in 5 seconds. If it dies real quick, you're too lean, if it dies after, you're too rich.

If it dies at 5 seconds, start it back up and run it back and forth for a bit. Now, let it stand at an idle for about 7 seconds. Then mash the throttle trigger down. If it boggs and sounds like it wants to die and then starts to accelerate slowly, your low speed needle is too rich. It should pretty much shoot off the line when you hit the throttle. Lean the low speed on hour incriments at a time and repeat the stand at idle for 7 - 8 seconds and take off process until the car shoots off pretty nice.

Now once that's done, turn your attention to the HSN (high speed needle). Once you shoot off the line and get it up to speed, does it sound like it bogging down a bit? Is there a lot of smoke coming out of the pipe? If so, start turning the HSN clockwise in 1 hour incriments. You'll start to notice it goes faster at the top end and each time a little less smoke is coming out of the pipe. If you turn it too much, there will be almost no smoke coming out of the pipe and the engine will start to over-heat. NOT GOOD. Turn the HSN back one hour and you're set. Keep a nice thin stream of smoke coming out of the pipe. A quick field test for over heating engine (if you don't have a temp gun) is to give a light spit on the top of the cooling head. If it bubbles off nicely you're OK. If it fizzes off instantly, you're running too lean and over heating. Richen your HSN a bit.

Remember, other factors come into play as well; ambient temperature, humidity, elevation, etc. So if one day your engine is running fine, but the next it's not, you probably just need to slightly retune it.

Also, keep a few spare glow plugs at hand. These wear out and will need replacing every so often.

Good luck.

RE: xtm xt2 problem
 

hi can u just clarify what u mean by make sure the piston is bottom dead centre

RE: xtm xt2 problem
 

OK, the piston goes up and down during it's travel motion through the piston sleeve.

When it hits the top of the sleeve, compressing the air fuel mixture it explodes, pushing the piston down through it's bottom stroke.

The piston sleeve in your engine is tapered slightly at the top. This is how compression is achieved, due to the fact these engines don't have piston rings.

As your engine heats up, the piston sleeve expands from heat. As it cools down, it will shrink down again. If you don't set your piston at BDC, you'll screw the piston sleeve up because it can't shrink back down because the piston is in the way. You end up loosing compression and power. You'll also possibly end up with a stuck piston. Not good Yano.

To find out where BDC is, take the glow plug out. Now take a thin (clean) plastic straw and put it down the hole. Now turn the flywheel, you'll see the straw move up and down. As it goes down and starts to come back again, you'll see where BDC is. Take a sharpie or something like that and make a mark on the side of the fly wheel and make an adjoing mark on the chasis. Now all you have to do is line up the marks, and you'll know you're at BDC. Some people put a more permanent notch or scratch instead of a pen mark.

Good luck.

RE: xtm xt2 problem
 

im going out of my mind with all this begining to wish id never got it. which one is the fly wheel? the one with the teeth or the one that turns reasonably easily without the teeth

RE: xtm xt2 problem
 

Go to youtube and type in nitro breakin video. You will find several. Watch them a time or 2 and then follow those instructions.

Eric

RE: xtm xt2 problem
 

i am going to ring the shop this morning, im sure it must be defective.

RE: xtm xt2 problem
 

What makes you think it's defective? Is it not starting now or what?

Mate, experience takes time, trial and error. We've all been there and had to go through this learning curve. Some of us with absolutely no outside assistance.

Don't get too frustrated. This is a very fun hobby. You can always ask questions in here, and I'm sure your hobby shop will be happy to help and answer questions for you, if they care about any future possible business from you. ;)

Let us know how you get on.

The first pic is the flywheel, the second is your center spur gear and the third is the clutch bell.

The flywheel is fastened to the engine drive shaft. Turning the fly wheel moves the piston up and down.

RE: xtm xt2 problem
 

Here...

RE: xtm xt2 problem
 

well its reluctant to start now, when i take the glow plug off it usually dies straight away.

RE: xtm xt2 problem
 

OK, take your glow plug out completely.

Tilt the car on it's two left wheels and pull the starter cord a couple of times to clear the piston chamber. (you may be flooded)

Cover the tip of your muffler pipe's stinger with your finger and give a couple more tugs until you see a couple of light droplets of fuel coming out of the plug hole. Now your engine is primed

While your glow plug is out, hold it against the glow plug igniter, it should glow bright orange. If not, then you either need to replace the glow plug or make sure your glow plug igniter is fully charged.

Put the car back on all four wheels and replace the glow plug, turn your transmitter on, turn your car on, and plug the igniter in. Your car should start up pretty quick.

By your description, I opt to feel you may need a new glow plug. These get fouled pretty easily when the engine is new and it's recommened you always have a few at hand.

Good luck and let us know how it goes.

RE: xtm xt2 problem
 

thanx for all the advice you're all really helpful. i have left it with matey in the shop so hopefully he will be able to sort out what ever is up with it. sometimes it does fire up and tick over but if i give it any throttle just dies again. so much for 'ready to run'

RE: xtm xt2 problem
 

Dont blame the manufacturer because of your inexperience. It is RTR, but you have to break in the engine slowly and you absolutely have to know what to listen for and how to tune when you are running a nitro.

Im not dogging you, we were all there once, but you have to be patient when breaking in a nitro engine. Once you get it broken in, you will be having a ball. Nitro's are kind of for the person who likes to tinker some.

This might give you some motivation. Its my old XTM XT2 with the XTM 24.7 engine. It was a blast to run it, and I kind of regret selling it, but I have an Ofna Ultra LX pro coming and I have another XTM 24.7 to put in it. They are awesome engines. Very easy to tune with lots of RPM and plenty of torque. You can see how well the engine runs and idles even in below freezing temperatures.

http://www.youtube.com/watch?v=NklJ_kL5uNA

Eric

RE: xtm xt2 problem
 

rite, had the shop on the phone this morning, there was something up with it. a washer had come off of the piston or something? i have to go and collect it in an hour or 2 so i will let you know how shes running

RE: xtm xt2 problem
 

is that yours is it? i have already seen that vid and was showing my mate it the other day

RE: xtm xt2 problem
 

Yes sir, that is my video[8D] I really liked that buggy and kind of wish I still had it. It was just a nice basher buggy all around and I had a lot of fun with it and never boke a single thing. I wish i had some better video of it, but I sold it before it got warm outside so i didnt get to video much. The engine ran awesome though, and as i said, I never had a problem with the rest of the buggy either.

Good luck with your buggy. Hopefully it was a simple problem and it will run well for you now. Just get farmiliar with tuning it and keep up the maintenance and you shouldnt have many problems[8D]

Eric

RE: xtm xt2 problem
 

HUHHHH???? SAY WHAT???

Please get a complete explanation from the 'bloke' at your lhs mate.....

RE: xtm xt2 problem
 

well he said something hadnt located corectly or something by what you just said it sounds like it could have been something serious? it seems to be working perfectly now tho. i took it out this morning

RE: xtm xt2 problem
 

No mate...the piston in these motors of ours don't have a washer......that's why I said "HUHHH"....

If that's still what he's saying, I would go back and ask him for a complete and full description of what he means...:eek:

Glad to hear it's working ok though now. ;)

RE: xtm xt2 problem
 

it does seem a little spluttery. i think i may need to adjust the idle screw

RE: xtm xt2 problem
 

Keep it rich for now mate.

When you say "spluttery", is that when you first go off the line from a standstill, or when you're going 'full steam' and it doesn't quite feel like it's going as fast as it could?

RE: xtm xt2 problem
 

when i go off of the line. plus i need 2 put my foot infront of it when i start it or it will drive off on its own (slowly).

also if i pick it up when i have started it the engine goes crazy like i am full throttling it

RE: xtm xt2 problem
 

its more when i go of the line

RE: xtm xt2 problem
 

I'm guessing you've finished the break in procedure by now. If that's the case, I'd start to lean out the low end needle a bit, turning it clockwise at 1 hour intervals.

But before you do that, you need to sort the other issues out first.

With the transmitter and receiver on but engine off, take the air filter off and look down the carb hole, hit full brake. Now you should only see about a 1 mm gap between slide and venturi (or the side of the carb hole). Release the trigger and it should stay there and not open up.

If it does, it could be your trim settings on the transmitter, the brake/throttle linkage set up or the idle set screw.

Work on those settings and get the car to the point where it idles properly. Then start tuning the low end on the engine.

If when you fire the engine up and it's idling properly and the wheels are still engaging and spinning, I would check the condition of your clutch and clutch shoes.

Is there a club or track anywhere near you that you can find some help at? If not, and you get confused, take it back to the LHS, have them start it in front of you and explain the situation. Then WATCH what they do and ask questions.

RE: xtm xt2 problem
 

hi thanks for the reply, which one is the low speed one? is that the other one? (not the idle screw)

RE: xtm xt2 problem
 

This is from page 12 of the XTM owner's manual. Take a minute to read pages 11 and 12 mate. Very useful stuff in there...:D

RE: xtm xt2 problem
 

i only got like a 2 page leaflet in with mine. the box had been opened already and there was a few bits missing, thats another story tho. lack of instructions could be partially responsible for why i am having so many probs.

RE: xtm xt2 problem
 

Email attachment is the Owner's Manual in PDF format mate. ;)

Good luck

RE: xtm xt2 problem
 

<font size="4" color="#000000">could somebody explain to me what a trasponder is? i seem to have a 'transponder mount' in the car but have no idea what one is.

cheers</font></p>

RE: xtm xt2 problem
 

Transponder is an optional part that is used when racing in organized off-road buggy races. It communicates with the computer through the 'loop' to give your timings and position in comparison with the other racers. If you participate in organized racing, most tracks will have rental or hand out units.

RE: xtm xt2 problem
 

ah cool i thought it was something like that. thanx

RE: xtm xt2 problem
 

What about your other issues? All good now?

RE: xtm xt2 problem
 

yeah seems to be fine. do i need to use any oil at any stage? is there oil in the fuel?

RE: xtm xt2 problem
 

What fuel are you using? There will be a label on the container that should tell you how much percentage nitro is in the mix, as well as oil percentage.

If you run your car/engine every week...don't worry about it. If you leave the car/engine sitting for a couple of weeks without running it, put a couple of drops of ARO (after run oil) down the glow plug hole.

Take the plug out, put a few drops down the hole and put the plug back in.

***Make sure the area around the glowplug is free of dirt, sand, etc....you don't want ANYTHING going down that little hole mate.

Let us know......

RE: xtm xt2 problem
 

nice choice! i love my xt2! but be careful with oils, the xtm 247 has a sensitive owb... (one way bearing)  but this buggy is durable!! i havent broken anything yet, and that includes crashing a fifteen foot jump off a culdasac! although, be prepared to replace the throttle servo... mine went out pretty quick, and my friend has the same buggy and his went out too.  he broke his cause he smashed into a horshoe pit pole at full speed! ahah and i broke his before that by jumping a little to high off a narrow jump and landed on one wheel... haha
 but all and all, a solid, fast, durable (but maybe not the greatest at handling.. its heavy!) buggy!

RE: xtm xt2 problem
 

The XT2 is heavy, but they are great buggies[8D]

I will also agree that the one way bearing in the 24.7 is finicky. Mine would always start, but you had to play with it to get it to catch a lot of the time. I bought a starter box recently for my new buggy though, and i really like it. Much better than messing with a slipping OWB.

Eric