Weird engine problems?

[bubbadee5]

Okay I am running a 2.5 tmaxx that I recently bought used and working on tuning the engine but have run into some weird problems. First is that I can start the engine when its cold and then run it for a bit then it suddenly dies like 5 min into a run. When I try to restart it it just turns over and won't start. I checked the engine and it is not flooded and the glow plug is good. I can let it sit for 20 minutes and then start it up again no problems. Does anyone have any idea what is wrong. Thanks.

 

[mrbones]

I had a 3.3 that did this and I had to replace the piston and sleeve because the pinch was gone. It would start up OK cold but once it got warm it stopped and I couldn't start it back up until it cooled.

 

[bubbadee5]

Thanks so much. I am already buying a new engine so I guess the problem will be fixed then.

 

[REVO-5309]

yep piston sleeve. might be worth doing the trade program with traxxas and get a new 3.3 motor.

 

[bubbadee5]

Okay with the trade program I can get the 3.3 for the same price as a dynamite .19 engine. Which one should I go for.

 

[SchrodeMode]

I would get the 3.3, the Dynamite isn't a direct drop in. The traxxas air filter fits too loose and it fell off during one of my bashing sessions, I may bash harder than some but I replaced it with a Dynamite filter and haven't had a problem since. I'm also not a big fan of the traxxas header on the .19, I've been fighting excessive fuel and oil on the car because of it not having a good seal, I just put a bigger gasket on and will see if it fits. Other than these issue, I love my .19 so you should be happy with whatever you get. If you get the 3.3 you could look into the carb from a Losi 3.4, it's supposed to wake the engine up a good bit.

 

[Zdragon71]

The dynamite is too a direct drop in. I've got it in my 2.5 tmaxx and the only thing you have to do for the filter is put a zip tie around where it goes on the carb body. Or you can just get a dynamite intake and filter. I didnt have to change anything in order to put the .19T in my 2.5 chassis. It even states that it is a direct replacement to the 2.5 and 3.3 engines.

 

[bubbadee5]

What about the 2.5r. I dont need all the power of the 3.3.

 

[Zdragon71]

Get a dynamite header seal to fix your leaking exhaust problem. They are thicker than the trx seals. I'm running mine right now with the stock 2.5R header on a .19 engine and no leaks.

 

[Grave]

What about the 2.5r. I dont need all the power of the 3.3.

I have the 2.5R in my MAXX & I Love the engine & think it's a "just right mix" for the RIG itself. Athough I have thougt about droping in the TRX 3.3 but I have a blast running my MAXX with the current powerplant...

 

[Zdragon71]

I love my 2.5R in my revo. Honestly I've geared it to where it actually runs as fast as the .19T in my tmaxx. It has been a great engine since breakin. I've now got around 3 gallons thru it andit still fires up everytime and tunes easy and holds a tune great! So i think you will be happy with the 2.5R

 

[Phins Fan]

Going back to the original statement of the thread - I'm curious if you know where your temps are running at? Having it set to lean or an improper tune will also give you the same issues you talked about. ont get me wrong - I replaced my 2.5 with an OS .18 and will never look back but wonder if you have a tuning issue over everything else

 

[bubbadee5]

Well after much tuning and trial I got the engine to run but now matter how much tuning it would shut off after it warmed up. And I don't know about the past running of the engine because I bought the car used and expected to replace the engine shortly after buying the car.

 

[Zdragon71]

Sounds like the piston and sleeve may be worn. When it warms up gets hot and looses compression and when it cools back down will start again is a common sign. Time to get a new engine my friend. My revo was that same way when i first bought it. Same week went ahead and bought a new 2.5R off ebay and been running it for over 3 tanks now and still strong.

 

[Bkyd Basher]

I just purchsed a new 3.3 from ebay for 90 shipped with no carb. Thought that was pretty reasonable. And so far so good.

 

[Greywolf74]

Does your 2.5 run after its warmed up if you just let it sit there and idle? if it doesn't then Id say time for a new piston/sleeve/motor.......if it does id say you have a tuning problem

 

[bubbadee5]

no it only runs when warm if I'm giving gas. as soon as i let it idle it dies