View Full Version : Quick question, Traxxas...
01-24-2001, 05:18 PM
I have a friend who uses a yank eliminator to start his Stampede. The bushing on the back plate kept getting dirty and wearing out, so he replaced it with a sealed bearing. This caused the engine to run for a few seconds and then become progressively leaner until it quit. A Traxxas employee told him something similar to "The crankcase became pressurized causing the lean condition, etc." Can anyone explain to me the science of why this happened? Why can't the back plate be sealed?
01-25-2001, 12:38 PM
You need the crank case pressure for the engine to perform properly. The bushing is a soild piece of brass as oppossed to the bearing. What's probly happening is that the pressure is seeping through the bearing and escapeing, thus causing the engine to perform erratically. The bushing, being solid,acts as a seal to keep the pressure in the crank case.
Hope this helps you.
01-25-2001, 07:58 PM
No, man, its exactly the opposite. He installed a SEALED bearing. It has to have the bushing because the tolerances are lower and it allows some air to escape under pressure. I don't really understand it, but I do know that the bearing makes it TOO sealed.
01-26-2001, 09:16 AM
How can it be too sealed? the block off plate you can buy (if you decide to get a starter box) is completely sealed.
I would say his problem lies elsewhere.
01-27-2001, 09:47 PM
Listen, I don't know everything about it. Thats why I asked. I do know this.
1. My friend installed a sealed bearing in his backplate
2. Engine would idle for a few seconds and then idle progressively higher until it quit
3. He then installed a regular (non-sealed) bearing.
4. Same thing happened, only it took a few more seconds.
The big kicker:
The engine runs like a top with a stock bushing in there.
Now do you still think the problem lies elsewhere?
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