Well, today I was out bashing in the snow with one of my 4910s and right at the end of my 2nd tank, POP!
Running 20% Traxxas top fuel.
Amazingly, nothing seems damaged.
The bearings are fine, no grind, smooth and tight. Has plenty of compression. I broke this motor in 7 years ago using the same methods for the 2.5, but then shelved it once I got a new 2.5. Built this 4910 last week out of spare parts so I used this motor. It sat for a loooong time, but it was in a sealed plastic bag and soaked in after run oil.
I have been looking for another crank, cant seem to find one.
Has anyone had the crank shear off like this before on any motor?
This engine has less than 2 gallons on it, and I just recently started tuning it for more performance. It was cold today, so the motor never got above 150F.
Looks like the old 15CV is going back on for now; it has over 6 gallons of 20% on it.
Sounds like a question I would be asking the manufacturer.