912UL Issues

[68niou1]

So the new dog gear and big gear are thicker than the original, so in my case even with the shims removed I still couldn't get the keepers in so I had to machine the lower spacer. Nothing is easy when it comes to Rotax. Got the gearbox back together, replaced the lower drive gear, and ran out of time
So I won't get a chance to finish putting everything together til after the first of the year-

[Av8r3400]

Thanks for the update and photos, Scott. I'm hoping to get out to the hangar and work on mine over the holidays.

How much heat did you need to use on the big 42mm nut?

How about talking abut the alignment for the crank pin situation?

[68niou1]

No heat. The nut was not hard to get off. My only issue was locking the crankshaft, the manual tells you to pull a plug and find top dead center, then put the lock screw in place. What it doesn't tell you is when you look in the hole and find the space in the crank it's really easy to put the lock screw in the wrong place. If you put the lock pin in and you get any movement at all at the prop it's in the wrong place. You need to look for a slot that looks like a timing mark, not a gap. There will be no movement with the lock pin in the right spot. I also used my special Honda tool (basically a custom 42mm wrench) to take off the 42mm nut however I think a 42mm socket from harbor freight would work just fine.

[pyolet]

I posted on your prop vibration thread about this....be sure to check compliance with Kitfox SB #54. Sounds trivial, but I believe a lot of the engine vibration related failures (clutch dogs, fuel pump, ignition modules, carbs...) can be attributed to this. It made a dramatic difference for my install. I've attached a pic of one of the spacers from my KF2 mount....they were all 3/16" too long. FWIW, Woody.

[68niou1]

Appreciate the input- if I forgot to note it already in the thread I have already done SB#54. Larry has as well. Definately appreciate everyone's input as it is all helpful.

[Av8r3400]

I would agree whole heartedly with this. My mounts were not in compliance with this SB. Though I believe my gearbox was too far gone for this alone to cure the problem.

Today I was able to get my new gears and dog ring installed. I ran out of daylight to do a test run. That will have to wait for a few days because we are getting another arctic blast here.

In the photo below I highlighted the crankshaft visible through a port in the crank case. It shows a notch in the crank that the locking pin goes into allowing the removal of the crank nut holding the drive gear.

The nut is torqued to 147 foot pounds. That's pretty tight, but not the end of the world. Keep in mind that the nut is a reverse thread, too.

[68niou1]

Update- today was the first day I had a chance to finally get everything back together. The weather partially cooperated and my buddy Frank came over and kept an eye on everything outside while I watched inside stuff. Vibration and ratcheting is gone. Runs turbine smooth at all rpm ranges. Did not get to fly it yet as my doors are still off, but currently it appears that my problem is fixed. Hopefully Larry's is too-

[DesertFox4]

Great news Scott. Now we wait for Larry to post equally good news.

[Av8r3400]

Aside from the weather kicking my butt, I'm working my way through round two of the bronchitis/pneumonia thing….

I was hoping to get her running this Saturday, it's going to be balmy in the low 20s, but I doubt that's going to happen now.

I did get everything put together last weekend and discovered a leaking fuel pump. Luckily I have a spare to steal off my Mangy Fox project. Once I get that installed I will definitely post the results.

[DesertFox4]

Aside from the weather kicking my butt, I'm working my way through round two of the bronchitis/pneumonia thing….

Larry, hope you're feeling better soon.