I decided to pull my tmaxx w/ xtm 24.7 engine out of my closet after having not messed with it for probably a year and get back into the hobby. I'm having issues with WOT, it also seems to not alot of power, i have to give it 1/2 throttle to get it moving good. And if i open it up it tries to stall or cuts in and out. But up to 1/2 throttle it runs pretty well. I noticed i can't do wheelies and its not responsive at all. Aparently the xtm only has 2 needles on it, i adjusted the idle so the wheels didnt turn on idle and have been playing with the HSN at first there was alot of blue smoke so i leaned it so there was a slight trail but it only slightly helped the power issue but did nothing to the WOT. I'm thinking glow plug but want to make sure before driving to the lhs
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XTM 24.7 poor performance, can't WOT
- Thread starter tmaxx4eva
- Start date
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When you put it away a year ago, did you clean out and pickle the engine? If not, you could have gelled fuel in the carb blocking one of the needles, or in the filter if you have one.
If you haven't done it yet, do a full tear down (including the carb) and clean everything with DA and q-tips to get any gunk out of the engine that you can. Maybe also replace fuel lines and check the filter if you have one.
If you haven't done it yet, do a full tear down (including the carb) and clean everything with DA and q-tips to get any gunk out of the engine that you can. Maybe also replace fuel lines and check the filter if you have one.
- Thread starter
- #4
when i put it away i took the plug out and squirted some wd40 in there and ran the pullstart a fewtimes and that was it. i replaced the fuel today as it was 2 or so months old so i thought mayb that was it. it will run wot now but the response still sucks and it seems to have to be run really rich to not cut out on WOT. and by rich i mean i now have trails of oil all over my driveway, if i lean it it does the same thing. so how far can i take the carb apart? i took it off the engine and took the slide? off but i dont have any DA at the moment, when i get some can i just soak the whole carb in it for a while?
jomofro39
RC Newbie
This has happened to me as well. I did a full tear down of 3 different engines (all sat between a year and two years after oiling them and wd-40ing the parts). there was definite gunk build-up that I had to remove, and I re-oiled everything and put them back together. One runs like a champ now (the TRX 2.5R), and another I am waiting for some screws to get back on my xxx-nt chassis, and the other one I just blew up the piston after trying to tune it. It would not WOT very well, and die rich, so I started to tune it. It began to get ideal temperatures and sound good, but the damned thing just wouldn't move like it used to (RC10GT, stock AE .15 motor). I sealed them all too with copper RVT, just to make sure. I believe that the motors just never will be the same after sitting for that long, and it is in the luck of the draw whether or not it will operate properly. A buddy of mine's .21 engine is doing the same thing, after complete re-builds as well. If anyone has specific counterpoints to my conclusion, I would love to hear them, but my theory is that them sitting idly by for so long just isn't good for them, and they will never run like they did the day you broke it in. Of course, if they did, how would these companies make money? 
Anywho, I say take it all apart down to the crankshaft, backplate off, and carb off, clean out the insides, piston head, and sleeve, reassemble, reoil, and seal the backplate and carb, let it sit a day to cure, and try to get it started on factory settings. This is what I have done to 3 out of 4, and one runs well, the other got taken out of my hands because my buddy had to leave for school, and I just blew a piston up on the RC10GT. Good luck!
Anywho, I say take it all apart down to the crankshaft, backplate off, and carb off, clean out the insides, piston head, and sleeve, reassemble, reoil, and seal the backplate and carb, let it sit a day to cure, and try to get it started on factory settings. This is what I have done to 3 out of 4, and one runs well, the other got taken out of my hands because my buddy had to leave for school, and I just blew a piston up on the RC10GT. Good luck!
Take off the HSN fitting, take the needles out of the HSN housing and throttle slide. Make sure to remove all o-rings before letting it soak in the DA. DA dries them out. Then do what you can with q-tips soaked with DA down in the holes for the needles. Just jam them in and spin them to work any remaining oil/sludge deposits out. Do the same down the carb venturi and the slide. Put some ARO on the slide, associated green slime on the o-rings, then put the needles back in.
I usually put RTV on both sides of the banjo fitting (fuel inlet on the HSN housing) to make sure it's nice and sealed as well.
- Thread starter
- #7
funny thing, while i was waiting a response i decided to give it one more shot at tuning it. i played with the damn thing for 1/2 a hour trying to get it started and i wouldnt have it. finally it started up and i was amazed it suddenly had power. i am running a little rich atm and i ran out of light to tune it more but I'm thinking that i must of clean whatever was gunked up in there with all the playing around with it. I still may take it apart and clean it but it will WOT not and seems pretty responsive.