Cracked Rotax Cases

ice42 sez:

“While this crack doesn’t appear to be as devastating or destructive as other submissions to deathrev.com, and its occurrence didn’t cause a hair raising pile-up, it was none-the-less painful when discovered. This 1985 600cc motor, now considered “vintage”, has been through alot of racing, and still remains competitive on the lakes in ice racing. I recently replaced the cases (admittedly with “good used” ones) and updated the headwork to the 61.5 hp package at a cost of more than i would like to share. So when I pulled the clutch cover off to replace what I thought was a leaking gasket I was shocked to discover the crack - I actually went numb for a second. Our ice season is short and unpredictable, and we are in the middle of it right now (January 2006.) Luckliy, the weather this year has been brutal (i.e. too warm) for racing and most of the bigger races have been cancelled due to sketchy ice conditions. However, the Nationals (our pinnacle) have been rescheduled for the last week in February and there is a slim chance i will be able to raise the necessary $1500 from “side cash” (money unknown to the wife) to get this motor back on the track. If anyone has a set of ROTAX cases I am in the market…..ice42″

[Pictures coming soon]

Twin Cam Tappet Failure

This is a shot of a 2003 FLHTCI crankcase where a tappet roller had failed. It might be hard to tell from this picture, but this motor required new crankcases, new cams, new tappets (obviously) and a new oil pump, at the very least.

Before it stopped running, this motor had high performance cams, hi compression pistons, SE cylinder heads, etc. I don’t think it was covered by warranty.

Take special note of the bore in the case where the rear inner cam bearing used to be. It was so far gone that the cam wore through the inner support bearing and began running directly on the crankcase. There is quite a bit of wear in that area.

RD 400 melt down

I hear that a two-stroke is more susceptible to ignition timing and fuel issues than a four-stroke.

The owner says “by the time I realized the improper fuel/ignition, I just decided to push it.”

Umm…….

No comment.

Gotta have a little fun too, right?

If you ever see these guys getting anywhere near your motorcycle, run the other direction.

CX 500 Dropped a Valve

This is one of two heads off a Honda CX 500. All I know is that the engine was being run at high RPM and it dropped a valve. Unfortunately, this is the only clear picture of the bunch that were taken.

The cobwebs are not normally present in a running engine. I suspect this head was sitting on the floor in a garage for a really long time, just waiting for its day on the Internet.

Blown Shovelhead Blew Up

These pictures are from a Shovelhead of unknown year. It’s a custom bike with a blower on it. We suspect the bearing supporting the end of the pinion shaft extension had too much clearance, and the bottom end starved for oil due to the excessive clearance.

This was a fresh motor with around 100 miles on the rebuild. The next rebuild is going to be really expensive.

CB 160 Broken Valve Adjuster

This is the cylinder head from a Honda CB 160. Unless you know what you’re looking at here, it won’t make much sense. In the picture, the valve adjuster is visible off to the side because it broke off the rocker arm. Cool.

Bent Valve

I forget what motor this is from. I had a half dozen or so, and without measuring, I can’t be sure which motor this is out of. In addition to being bent like a pretzel, the top of the valve broke off, above the keeper groove, and of course the valve guide was broken and the the piston was damaged. Let’s say “loss of compression followed.”

XL Pinion Gear

Not much to say here, except pinion gears on Sportster® motorcycles are supposed to be one piece, not two.
 

Not sure what happened here. Any thoughts? Post your comments above (or below, depending on what page you’re viewing.)