Ok I am a nitro newbie and have had nothing but problems with my engine. This is in my T-Maxx with the 2.5

First I installed a Tiger drive and before my break in was complete I couldn't start the engine I just got a metallic cranking sound turns out the one way bearing in it was cracked. Ok so I stick a pull start on it to finish break in. I think I am finished so I fill up to make some runs to tune my engine after a couple tanks with the max temp reaching 260 all of a sudden the temp has reached 340. I cool down take the maxx home and do an inspection on the engine and I break the pull start cord it actually had a melted spot on it. So I go to remove it and the shaft is blue/black from heat and the one way bearing falls apart. So I take the back plate off the engine and see that the heat came from the one way bearing cause the shaft further in the engine is not blue/black from heat but shiny silver.

My question is why am I eating one way bearings, should I get a new one way bearing and starter shaft (total cost #30) or should I just chuck the engine and get a new one? I really don't want to keep throwing money down the toilet.

This is really annoying since I have raced electric for 16 years and rarely have any kind of problem.

I've recently heard of problems with the one way bearing on 2.5 motors. As a matter of fact just until recently I couldn't find one ANYWHERE. A customer has gone through 3 or 4 on his Revo. What is causing the problem? I have no idea, maybe they got a bad batch or something. He was in the other day and said he had gotten a new starter shaft and bearing and was going to see what happens. The last one literally welded itself onto the starter shaft so he had to take it off in pieces. I now this probably isn't much help but it's basically a FYI. Personally I think I would almost look into a different engine. I hear the Fantom .18 and O.S. .18 are very nice motors.

Hmmm

You know what I find interesting is that nobody else hardly makes a replacement .15 for the Maxx. I really don't want a more powerful engine just a reliable one.

I've heard people swear by the 2.5 and others swear at the 2.5......

Same here. There are those that have very good luck with them and others that no matter what they do they can't keep them in tune or in this case, keep one way bearings in them.

Just as a side note. A guy that used to have a Maxx here had a O.S. .15 in his and it ran very well. All the power he needed and ran like a top.

As a former manager of a hobby shop...I'll give you my pennies' worth.

Traxxas makes fast engines at a budget price. The problem with that being they aren't always consistent. The goal was to have a powerhouse in the monster truck, not a power-reliable-house! nice coin eh?

I've seen lots of these incidents and it's just frustrating. Even when tuned correctly, the motor doesn't fire up very easily after the first 1/2 to 3/4 of a gallon of fuel. This wears on the starting mechanism (mainly the starter-shaft) fast. Believe it or not, there is more wear on the starter shaft than the one-way in most cases. The diameter of the shaft decreases every start, until it eventually is too small for the one-way to engage upon.

As you said, your one-way was split, which is also a common problem. The force of turning over an engine via the one-way, and then it firing every 1-10 or so strokes causes constant high-speed engagement, which is the same as landing from a big jump when your tires are spinning at 70mph, but the car lands at 20mph. A correct slipper HELPS to absorb the forces generated, but it's still hard on components. However, there's no slipper on a starter mechanism. The biggest problem is when the fuel is compressed, the glow plug is already hot from either a glow-igniter or the easy-start (traxxas), usually firing the mixture way before TDC, causing the engine to actually back-fire and generating enourmous force against the one-way....and you guessed it! Splitting the thing.

Maybe I'm just babbling....but oh well. The best solution is nothing, as I don't think any pull-start or easy-start is as relaible as a starter box...yet you can't fit a starter-box to the T-Maxx (Revo baby!).

Traxxas will replace the items though if you contact them. The best way to avoid the mishap is to use short (1-2 second) presses of the starter button. Also, get yourself a REAL glow-igniter and disconnect that stupid glow-plug lead. It will start soooooooo much easier. Follow these steps too:

1. When starting the engine using a REAL glow-igniter and assuming you have the glow-plug lead disconnected (blue wire). Make sure you do NOT have the igniter on the glow-plug. Plug in the easy-start, put your finger over the exhaust and press the button for a second. You should be able to see fuel in the line enter the carb and you will hear the engine rotate easier when it is primed. As SOON as this happens, stop!

2. Connect the glow-igniter and press the easy start button again. You may need to give some throttle if your engine is rich. You can leave the igniter on for a few seconds, but it isn't something I do, where others swear by it.

3. It should fire up a lot easier and will be much easier on the starting components.

Just my thoughts... Also, a hot engine is usually difficult to start and requires alot more fuel to fire back up. My recommendation of a real glow-igniter is that which uses a sub-C cell, such as Hangar 9's or McDaniel's. Many other companies make them too. A charged glow-igniter lasts me half a season, racing 1-2 days a week, which is on average 6-10 starts per race day. I see others last less than a day because people just leave them set on a plug...what a waste!

Thanks for the insight. Since I am racing my max I got rid of the piece of crap EZ start along with that piece of crap radio.

Going to try another one way bearing. I examined the shaft and while it was blackened it had no noticable wear on it. I turned it a couple times on a scotch brite pad and it was silver again with no appreciable wear.

I'm debating buying another engine so I can have two if one gives me fits again. Not sure if I want to buy another TRX2.5 or go another route and get the OS CV-RX .18

I got the truck two months before the Revo was announced and then the track never opened up last summer so the truck sat for over a year before I touched it. If I had waited I probably would have a Revo.

There's been several people around here that are happy with the OS18.

I realized last night after I posted my long explanation, that you said "Tiger Drive"...and it didn't even register with me about the EZ-start. I must have been really tired, as I wouldn't have gone to all that trouble in the post regarding the ez-start and the blue wire, etc, etc.

I haven't had an MT after the last T-Maxx I had, which was a couple years ago. Mine was decked out with rpm parts, and it really was nearly indestructible. Survived the skate park several times and lots of high and long jumps during some free-style competitions.

The Revo is nice in the aspect you can buy a starter box to fit it, in addition to its handling abilities.