Broken crank

[MCourson]

Well went kart racing today. Had some practice laps early on and then took a little break. Went out again. At the end of the back straight away I was turning my little 4 stroke 7400 RPM. In the turns on the other side of the track (3000' track, 1000' straight) I heard a horibble grinding sound and the back tires locked up. All I could do was aim it at the grass and hope it would stop me before the fence. Well go the kart back to the pits, tore it down and here is what we found.

 

BTW that is me in the back holding the other half of the crank. It got toe up.

 

If it wasnt for the billet connecting rod there would be many holes in the block. Luckily it only dented it and I know a talented aluminum welder.

[Zane]

Yikes!

[The SPEEDY]

D**n that sucks. What kind of motor is that? Do you race in 125 shifter kart?

[MCourson]

No shifter fo me. They are basically dirt bike engines. This is a Briggs and Stratton Animal engine. It is based off the Briggs Intek 206 6.5 hp pressure washer engine. The Intek has bushings in the crank journals this has roller bearings, ported head, .256 lift Dyno cam, Walbro PZ slide valve carb (basically the same as Mikuni and Kiehn), ARC billet rod, runs on methanol alcohol, and most importantly no governor. It is on a single gear kart with a centrifugal clutch. Puts out about 12.5 HP but can be built to put out well over 40HP.

[MCourson]

[The SPEEDY]

I have always wanted to do that stuff, just don't have the funds. Maybe when I get older I'll pay the high price for a 125 shifter and run it WOT through the hood. At 7:00 in the morning on a Saturday.