Nesal

Hi guys, well My jato has been acting up lately... first it burnt out glowplugs, I think it had an air leak and was running lean so i changed the tubing and it stopped burning them out. Then the airfilter came off and some junk got in my cylinder, cleaned it out but when I put the head back on the head gasket wasnt on properly and I deformed it as I tightened the cooling head, got a new gasket put it on, new plug and it ran great for 1 tank. Next day I take it out its running good and suddenly the electronics go on me, it was the receiver, I get that changed and now I can get it started but as soon as I go full throttle it cuts out.
Ive tried everything, richen the HSN, lean it... Ive done it all and the damn thing always cuts out as soon as I open the throttle, I dont think its lean and I dont think its rich because I had between doing all that as I was fooling around with the tuning I got it to go perfect for about half a tank the same thing happened, I changed out the plug (mc-59) to an OS nº8 and it was still doing the same. Engine seems to have good compression, no air leaks, fuel is getting to the carb.... what the hell is going on?? Any help is very much appreciated!
Thanks

Nesal

By the way, I put the 0.2mm gasket in and had the problem so tried the 0.3mm... Im using 16% nitro, should I try the 0,1mm? Didnt want to go too small... problem is the same with both stock (0.2mm) and 0.3mm gaskets.
thanks!

pieky22

well 16% isnt the best for a trx 3.3... but uhh have u tried the lsn? that could be the problem

dkastil

With 16% you remove a shim if you run 20% keep it stock and if you run 30% add a shim . I dont think the shimming or the plug is the prob the mc59 is a good plug and the stock shim setup will be fine with 16% , I think when you got the junk in your engine it got hammerd out your piston and sleeve and you stated that you usto burn alot of plugs that happens when you are running to lean (hot) I bet 280 to 320 a engine will cut out when it is overheated sometimes , do you check the themps or not ? knowing your temps helps alot so you can tune before you have a issue form overheating or running to cool. Traxxas replace engines for around $60.00 or you can rebuild your self for around 50 give or take if you hunt ebay for a piston and sleeve ,once your piston and sleeve are worn you just cant do anything ,my buddy and I had a few ebay trucks he had a rc10 with a os .12 and i had a xxxnt with a mach .15 they ran like junk we thought we just did not know how to tune or had a airleak or so we changed the tanks lines sealed and cleaned the engines sleeve and pistons looked good ,finaly I broke down and got a piston and sleeve and bam it worked started all the time and ran cool and strong and still does , one last thing is did you break it in with a proper traxxas or heat cycle ?

Nesal

Ok put the 0.1mm shim and wil test tomorrow, I broke it in with the Traxxas instructions... it might be the piston and sleeve but the engine only has a gallon through it so it shouldnt be that.... I dont have a temp gauge but would like to get one shortly... I do however check the temp roughly with my hand and am careul it doesnt get too hot, this of course in nowhere near as good a temp gun but better than nothing!

dkastil

you can burn your engine in a few bad tanks or some dirt in the engine .

Nesal

The engine has compression and starts up fine, any other thing it could be? Maybe a bearing in the engine or something? should be right? Maybe I should take the whole thing apart and clean it out thoroughly... what do you think?

125cchyperman

Maybe when the debree got into the engine it destroyed the chrome in the sleeve and took it off the exhaust port. I've had this happen to me but witha nickel coating though, not a chrome innersleve. But it's not totally impossible though for it to do it though with a abc engine. Try this, pick the truck up off the ground and try and go full throttle see where it cuts out at. Then try adjusting your needles accordingly. Also what does your plug look like, the look of a plug tells a story. It can tell you weather tour running way to rich, just rich, ok, lean or way to lean. I have a feeling that it's just your LSN and a bad needle setting. as you have stated earlier you were burning plugs which usally indicates a lean condition. But just because you go through plugs deosnt mean you have a lean condition though. Sometimes company's put out a batch of lemons for glowplugs. I went through 4 glow plugs in less then a half gallon one time with a perfect tune. went back to using the old glow plug and was fine, went back four days later and told the LHS about it and said others had done the same thing. So it happens.....

When it comes to engine temps though dkatsil. some engine's like to run that hot especially trx 3.3... I have seen engine's run through many gallons being run at 300 plus degree's, but thats not really the point... Dont go off of engine temps, go off of the engine's tune, how the engine sounds and how it's performing. If you cvant do that then going by temp is your best bet, but only then is going by temp a good way(at least I think)

But with a .2 mm shim you will be fine, even using a .3 m shim you should be fine, you'll just be a little low on power and compression but you'll be fine though.... You just wont get th epower outof it that you would want, but a .1mm-.2mm shim is ideal for 16% nitro though.

Nesal

Ok sounds good... do you know the factory setting for the trx 3.3? will try that and go from there, thanks!

125cchyperman

Im srry I do not, but Im sure someone here does though. But as said it sounds like bad needles setting if that doesnt work you mighta ttok some of the chrome off the exhaust port which would mean you either need a new p/s combo or a new engine....

Nesal

Ok, I got the factory settings will try that later and hope it works!!

Nesal

Ok, with needles back to factory settings the thing starts buts cuts out as soon as I remove the glowplug igniter... does that mean I need a new piston/sleeve or is there still hope?

dkastil

try a new plug

241 racing

My Feedback: (20)

Try a new plug and if it starts and dies when you remove glow ignighter it's to rich.Lean it a tad and you should be good to go.

Nesal

Ok will do... thanks!

Nesal

Ok, tried leaning out a bit, it still cuts out!! Not as soon as I take the glow igniter off but about 5 seconds later, and will cout out as soon as I apply some throttle... I am willing to get a new piston/sleee but what worries me is the fact that that might not be the problem and if I spend 60€ on a new piston/sleeve and that doesnt solve it Im screwed and have thrown my money away....
Do you think that will solve it 100%? I just dont see anything else that it could be...
Thanks

chris6414

My Feedback: (10)

When you say it cuts out, does it sputter and cut out? It still maybe too rich. When my motor is cold, I need to trim the throttle up a bit till she warms up or it will stall. These little motors are very tempermental when they are cold. You said it ran a little longer after you leaned it. Lean it a little more till it runs consistant. You may need to trim the throttle up durig warm up though. I always do a slow 1/4 throttle run around the yard before I hit the throttle hard. What happens is the fuel cools or puts out the coil when you remove the igniter. I have to trim my throttle a tad for the first minute of running until it warms up. Then she runs good. If your running lean on throttle up she will hiccup or skip because it is sucking air. Be sure if you hear that to stop or the motor will overheat. Mine does that when she is about out of fuel. It won't except any throttle above half when it gets low.

If it just quits when you apply full throttle, then it(LS) is too rich. Too much fuel on transition just puts the coil out. One test I did was to warm up the motor with some mild throttle up runs, then push my nose down and hold it and then nail the throttle briefly. It keeps resistance on the rear tires and won't overspeed anything. It will get you very close to optimum LS needle settings. If she hiccups, then go 1/8 turn richer and so on. The pinch method is also a good gauge of LS needle settings. Warm up the motor and bring it back and pinch the fuel tubing about 3-5 inches back from the carb and count how long it takes to shut off. 3-5 seconds is good. Too soon and it is lean, too long and it is rich and will quit on throttle ups or won't idle smooth.

Chris

Nesal

Ok I can get it to idle but cant get it to not shut off once I open the throttle past a quarter.... LSN is at factory setting and I have leaned the HSN from factory settings, should I lean the LSN?

dannthenitroman

How does it stop? suddenly, maybe with an audible 'click' or slowly with a lot of smoke?

Dann

Nesal

It stops as if fuel doesnt get to the engine... takes about 1-2 seconds so is pretty immediate.

dannthenitroman

so you pull the throttle and it starts to die and after 1-2 seconds it stops? well thats actually quite slow. sounds very rich. lean it out some more and test (remember because your leaning it you have to be careful so dont be ultra throttle happy cos if it doesnt need to be leaned and its a mechanical problem you dont have as much lubrication as before).

Dann

chris6414

My Feedback: (10)

LS is still too lean, open it up a 1/4 turn. Pinch should take 3-5 seconds(after a run to warm things up). if you can't even get it going than it is too lean. If it was rich it would slobber then quit. When it is cold don't punch it. Do a slow low throttle lap to warm the head up. Make sure the HS is rich at first with 4 turns open. Then, lean it out after some full throttle runs. If you can't transition from low to high it is the low speed. After 50% throttle the HS takes over. My LS is set richer than factory, otherwise I get some missing.

dannthenitroman

he means 1-2 seconds after he gives it gas not when doing a pinch test. if it were too lean and were cutting out at 1/4 throttle it would be a lot faster than 1-2 seconds and it sounds as tho it idles fine.

Dann

envy1234567

i to have run into this very same issue on my jato 3.3 slowing down and stalling at WOT i reset the needles and spent awhile tuning it back up now it accelerates at WOT nicely driving at half for while now causes the problem... (still working on it) all just fine tunes a slight over turn will throw it off.. tedious work i know but it all counts

dkastil

if it burbles and bogs right after you punch it the lsn is to ritch if it dies in the mid to upper power band the hsn is to lean , and if there is any engine damage it will exaggerate the issues