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3.3 cutting out at WOT

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M

Morpheus

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  1. Bashing
Ok, have less than an hour on the new 3.3 T Maxx, AFTER break in. I broke it in according to the Traxxas DVD. It's cutting out at WOT, and its only getting up to about 250 degrees F. So I richen it up thinking it would fix the problem, and now it dies when I give it WOT. It'll run fine all the way up to about 3/4 throttle, and anything after that, it cuts out, then immediately dies. I've turned the needle almost a full turn out from factory settings. I have started leaning back out some, but I was loosing daylight, and had to put it up. You think I may have richened it too much? I'm thinking I just need to fine that middle point, should I keep leaning it a little bit at a time to see if that works?

T.
 
Cutting out has always been lean or sometimes a bad plug in my experience. Also make sure your lines are good and clear of obstructions.
 
Yes it sounds like you were running too rich. If you were getting to 250 that is just fine if you are running hard. You could even lean use a tiny touch more if the engine lets you performance wise.
 
Id put it back to factory settings, and go from there. If you lean it to much you run the potential for ruining your brand new engine. A lean engine at wot will shorten the lifespan
 
Well, he said he was almost back at factory setting already and if he keeps richening the engine and it's not helping....then he needs to try something else. But that is just my opinion.
 
I'm sticking with the glow plug idea myself, when in doubt, swap it out, especially on a brand new 3.3.
 
My new SH .28 would die on throttle due to the LSN being too rich. But that was not at just 3/4 > throttle.. Mine would die after any throttle input, as soon as I'd let off.. But just another idea.. Definitely try a new plug first.. The breakin richness could of fouled it..
 
Yeah, I forgot to mention that I did change out the glow plug. I'm just gonna lean it out a 1/16th at a time, just to see if it stops dying, then go from there. Thanks guys.

T.
 
I've had many problems along the way with my t-maxx 3.3 and got me LHS to do my first tuning after break in then i decided to play around and see what would happen when i started playing with the LSN and HSN to see what happens so that later on when i get that symtom i know exaclt what to do and it still took me about 2 months to get the whole on the fly tuning down but I'm no pro even tho this is a serious hobby. we all have to start someplace and the best thing to do is to play around with the needles untill you understand what they do. to tell the truth i almost gave up a few times but now i love it
 
Well, yesterday, I set it back to factory settings, and it's doing the same!! I'm a little baffled. When I turned the high speed needle back all the way in, I was shocked at how much I had to turn the thing to get it all the way back in. Probably six or seven turns to get it back until it stopped! I was expected closer to 4 and half maybe five turns! I turned it out to four turns, and I couldn't tell a bit of difference, so I'm just gonna have to play with it some more, and if nothing else, I'll bring it in to the LHS, but thing is, the guy who has tuned all my rigs thus far, in now in Houston setting up another hobbie shop, and the guy they have now, is definitely sharp when it comes to replacing parts, building them, etc, his tuning skills just aren't up to par, so I'm sorta stuck out in figuring this out for myself. If I get a few beers down me, I'll have a little more patience I think! LOL! Oh, and btw, the 4500 mAh battery I got, held up to about 6 hours of playing, and starting, and still had plenty of juice left! That thing is awesome!

T.
 
No, haven't sealed it yet. Figure I would at least exhaust all my options in tuning first. I still need to spend some time with it. Yesterday, I had two of my other buddies playing with me, so I only spent about 45 min fiddling with it. They were having too much fun, so I put it up, and brought out the 2.5. I'm gonna spend some time with it this weekend by myself, and see what I can do. I plan to seal it, but I want to try and tune it first. I have some upgrades I'm gonna do on it, and when I do, I plan to seal the motor then. The LHS does a free tune if you buy from them, and I had the free tune done, and it ran great for about 45 min, that's when it started acting up, and bogging down. The temps have not gotten over 252, and it's maintaining temps in the range of 220-250. Are air leaks common right out of the box??

T.
 
Sealing an engine is the first thing to do before exploring any other options. It's very common to have an air leak develop through the factory seals. Until you seal it, your pretty much wasting your time. And your engine.
 
Was it just me, or was the forum down yesterday?? Anyway, to update you on my issue, last night I was cleaning my 3.3, and doing the after run maintenance on it. When I took out the the glow plug, I took out the copper seal so I could Q-tip the inside of my head to get any oil or debris, and I noticed that two seals came out from the head. Could this cause major tuning issues from not sealing tight??

T.
 
if you had seals come out of the combustion chamber area then you have a seal problem(s), nothing should be in there, tho i have no idea what seal could have made its way in there but that is my guess, but I'm no expert.
 
No, it was nothing like that. The copper seal that comes with every glow plug, copper ring, whatever you want to call it, there was two of them attached to my glow plug, like it was left from the last one. Will this cause problems?

T.
 
Sounds like you found it.

Try holding the engine upside down and shooting nitro cleaner or carb cleaner in the head before you remove the plug. It's the safest way to clean around the glow plug hole. Watch out with carb cleaner it'll weaken or even ruin your plastics......But it does smell good:jittery::jittery::jittery::jittery::jittery:

Two copper washers will back off the engine's timing, could have been the problem I guess.
 
Last edited:
2revo1maxx said:
Sounds like you found it.

Try holding the engine upside down and shooting nitro cleaner or carb cleaner in the head before you remove the plug. It's the safest way to clean around the glow plug hole. Watch out with carb cleaner it'll weaken or even ruin your plastics......But it does smell good:jittery::jittery::jittery::jittery::jittery:

Two copper washers will back off the engine's timing, could have been the problem I guess.
Click to expand...

2 washers could and will also alter compression ratio and the heat and efficiency of the burn.
 
Update...I set everything back to factory settings today, started tuning on it, and I just about got the cutting out to stop, I was getting oh so close. It died, as was normal, this was pretty common when it was cutting out. I re-fueled, put a new glow plug in (Ez Start wasn't registering the glow plug) it wouldn't crank for crap! After checking the obvious (loose hoses, loose glow plug, fuel tank cap, etc) I started on it again. Finally got it cranked, it was smoking like crazy, I would give it full throttle, and it would just sit there. It sounded like crap, and wouldn't stay idling for anything. To make a long story short, I finally put my hand on the fly wheel, to see if I could turn the motor over, and it did, but it was entirely too easy! I was WTFing at this point, and new something wasn't right. I called Traxxas, they told me to send in the motor, along with receipt, and if the motor was defective and since it's only 5-6 weeks old, they would replace the motor at no charge, but only as a courtesy. The hobbie shop also confirmed my findings. So off I go dis-assembling the motor and to my surprise, as soon as I get it off the truck and turn it upside down, I saw the problem! The rod broke through the crank case, and there was a huge gaping hole on the bottom of the motor. It was the perfect fit for the counter weight on the crankshaft. I took pictures on my phone, but I can't post them, something to do with compatibility. I can't find my big camera, or I would. Anyway, I'm sending it off tomorrow along with a brief note of what happened per the Traxxas Rep. I broke it in correctly according to DVD, and ALWAYS did my after run maintenance even if it just sat for a day. I believe in taking care of my investment, we'll see what happens with Traxxas, the guy told me he would take care of me, so we'll see. Anyone ever had similar issue with a 3.3? It only had 9 tanks run through it!!!

T.
 

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