About to rebuild my carbs

[Dorsal]

The engine is 17 years since new, 7 years in service, 500 flight hours so it seems like a good time to replace all the rubber bits in the carbs (did so on the rest of the engine a year or two ago). Filing, removing then re-peening the butterfly screws seems the only slightly tricky part. Would appreciate any tips from those who have done it.

[Av8r3400]

"If it ain't broke, don't fix it."

Are you having an issue that needs to be rectified?

[Dorsal]

Nope, and I generally adhere to that principal but it did seem time for a thorough inspection/cleaning and while I am at it replacing the o-rings and diaphragms.

[Russell320]

Rotax-Owner.com has a great video on carb rebuilds. Watch the video, read the manual and have fun.....it's not too difficult. Oh.....and order your parts ahead of time.

Russ

[Dorsal]

Have, did and about to
The basic parts came in last week and it is no day for flying today.

[Dorsal]

disassembly went mostly as advertised including damaging the main needle fixation screw looks like I will leave that part assembled.

[Av8r3400]

Fin - If you are doing an ultra-sonic cleaning of the bodies of the carbs (standard procedure) do not forget that the ball-bearing blocked passages will need to be re-epoxied in order to prevent air leaks.

This is a commonly overlooked item which causes poor running after a rebuild.

[Dorsal]

Thanks for the heads up, not doing ultra-sonic at this time as everything looks quite clean (no build up). I am assuming you are referring to the material on the body of the carb covering these passages? some of that flaked off so I was wondering what to replace it with?

[Av8r3400]

Unofficially, any fuel proof epoxy will work. (JBWeld)

Another piece of advise, if your floats weigh fine, DO NOT REPLACE THEM. Seriously, if they ain't broke don't replace them!

[HighWing]

This is ancient history, but my tendency now would go with the ain't broke advice - with the exception of the diaphragm and other more fragile parts. When I did my overhaul in the old days, the first attempt at a test flight resulted in a very rough running engine with fuel all over the place below the vent tubes. I learned that they had sent another needle version that didn't stop fuel flow into the already "full" float bowls. I replaced with the old needles.and put another 600 hours on the airplane. A note on ultrasonic cleaning. What is being used as the fluid in the ultrasonic bath. The reason I ask is that there are numerous chemicals that can be used that would not harm epoxy but would loosen sediments for rinsing. Is the fluid prescribed by Rotax?