Thread: Screw-up with friction torque test - foreign body trapped in crankcase

This is epic: I thought (Dangerous!) I could probe the location where to locate the crankshaft stopper for the free rotation friction torque test done at the 100/200 hours service. I stuck the wooden handle of an old artist's brush to feel for the notch on the shaft. STUPID! a slight brush against the prop and snap the bottom of the brush handle, complete with shards of laquer are now down inside the crankcase!

Do I
1 Ignore it as its only wood and should chew up small then end up somewhere harmless? Dont think so, it could block a vital oilway to a crankshaft bearing?

2 Split the crankcase? $$$$$ for a 1/4 - 3/4" sliver of wood!!!

3 Flush it out through the return to the reservoir? Is there lip at the exit to the Banjo? And with what, oil, kerosene, gasoline? I think this is my best option, and a reminder to RTFM where the correct method of finding the notch is by far the best way to do it. And to think I wanted to abide by the book all the time!

Hi John,

Wish you would have ask me this question the other night. You can see the notch with a flashlight when you look in the hole. Nothing should ever go in the hole to hunt for the notch because even if it is solid steel you can damage the balance lobe, shave off metal and worse bend the steel or the actual pin and have to then split the case to remove it. There are holes in the oil routes this could plug up.

Let's see if we can get this out without splitting the case. I have never had to do this so I'm not sure if this will work.
The only thing that comes to mind is your third option. You will need to take the bottom muffler completely off. Remove the two large bolts on the bottom of the engine, one is the banjo bolt with the oil line. Then get a tube that will fit into the opening that you put the wood into and a 50cc syringe. I would take so 5w-10w oil, something thin and flows easily. Then I would flush a lot of oil and do a fair amount quickly, that's why the syringe, to get the wood piece to float and pray to God that the wood floats out one of the holes. I would put a strainer under the holes that the oil comes out of to catch and check for the wood piece. If the first flush doesn't get it then try several more times. If the wood piece comes out then put the system back together and you absolutely must do an oil purge. Before starting your engine. If this doesn't get it then splitting the case may be necessary and could cost a few thousand dollars. Please let me know if this works out for you.

Sorry your having to go through this,
Roger

Roger, I was speaking in the meantime to Conrad Beale, the main man for Rotax in UK. He remembered the oil tube 924451 on the RHS bottom of the crankcase, half inch I.D. in between both crankcase outlets. He is against any attampt to flush because there is the possibility that the offending article may lodge inside it and arrive on the scene later at the most unfriendly time. Now that leaves the option of lifting one or more cylinders and fishing it out. A lot cheaper than splitting the case. Bother. Maybe a good steerable endoscope with a suction device, dont even know if such a thing exists.

The endoscope does exist. The medical field uses them. They have a small pincher on the end. I have seen them.

I didn't think about removing the cylinder, it may work just fine.

Hooray Happy ending: I opened the crankcase blanking plug and it poured out with the oil. Lesson learned . The exhaust box needed removal to grease the joints so no sweat about that.

Happy ending indeed John,

The oil trick was a far cheaper try than removing a cylinder. Always try the cheap way first. I'm glad it worked out.
Now don't forget to purge the oil system. There is a good video of this being done on the Rotax website. Watch it first before the purge.

p.s.
Now to do the friction torque test just use a flash light to look for the "V" notch. The locking pin when in the right place should stick out 3/4" or 20mm. and the crank should then be locked. As you rotate the prop looking for the "V" you may see blackness at first then a shinny metal oily surface. As you go down the shinny oily surface about 3/4 of the way the notch will come into view.

Hi Roger I dont think a purge is necessary: all that happened was the normal quantity that wasn't gurgled spilled out the blanking hole, same as would come through on gurgling. So instead of gurgling it back to the reservoir, I gurgled it out the crankcase bung. I will fill the reservoir to the very top of the dipstick, run it a bit, then check as per normal.

Guess what as well, I think I will never again miss the shape of the indent as you described - its etched now into my brain!!!