Carb Float Weight

todehnal · #1 08-25-2016, 10:03 AM

It's condition inspection time now and I pulled the float bowls for inspection. Although I found everything clean, I decided to weigh the floats, and found that on the right carb, one float is 3.1 grams, while the other is 3.8. My engine, and carbs are not in the recall range, but I was considering just ordering 1 new float to replace the heavy 3.8 gram float. According to the sevice buletin, I am still within specs, but it seems a bit close to the total of 7 grams limit for the 2 floats. Any thoughts......Tom

todehnal · #2 08-25-2016, 10:23 AM

As a follow up, it looks like that if I replace the floats, I will be committed to the 25 hour inspections, just like the effected serial number group. Right now, as I read it, I am exempt from that.

PMLviator · #3 08-29-2016, 06:37 PM

How do you remove the floats with the drip tray right under the carb? Do you remove the whole carb and what do the drip trays accomplish anyway?

RFSchaller · #4 08-29-2016, 11:13 PM

If you remove the carburetor from its socket you can remove the bowl on the bottom and access the floats.

If you burp fuel out of the short hose that vents the bowl the drip tray prevents it from dripping onto the hot exhaust pipes.

todehnal · #5 08-30-2016, 05:58 AM

Quote:

Originally Posted by PMLviator

How do you remove the floats with the drip tray right under the carb? Do you remove the whole carb and what do the drip trays accomplish anyway?

Yeah, it's a pretty simple 5 minute job to remove a carb. No need to undo cables, just take off the air filter, pop off the spring, loosen the clamp, and slide the carb out. Then flip the bail and the bowl drops out. It's that easy. The problem is that the floats are expensive, and they still have not totally resolved the absorbing fuel problem with them, as far as I know. So, for now, I will continue to keep what I have. You would think that someone could make a reliable float for these things. Maybe too much R&D is going into fuel injections, and us carb guys are becoming more like a step child ....Tom

Jetguy · #6 08-30-2016, 07:19 AM

Here are a couple of videos off youtube. Note, this is not an RV12 but you will be able to see a carb bowl removed in the second video.

https://youtu.be/JdS7OtbcxwY

https://youtu.be/XBT-yQ_X3N8

You may concider joining Rotax-owner.com. There are many videos there about the
912 engine. Here is one on the Carb Floats recall.
http://www.rotax-owner.com/en/videos.../459-asb912069

Here is a listing of all their videos. Some videos you cannot watch unless you join the web site.
http://www.rotax-owner.com/en/videos-topmenu/all-videos

PMLviator · #7 08-30-2016, 08:24 AM

Thanks guys, I thought I would have to remove all the cables to pull the carbs out far enough to flip the carbs over.
John thanks for the video links.

dick seiders · #8 09-14-2016, 12:39 PM

I may be behind the curve here, but I am doing my Cond. Insp. next week and wanted to catch up on the latest float issue status. I learned from Lockwood Aviation, and Rotax owners .com that new floats have been produced that do not require the periodic 25hr/60 days float check. They are part no 861185 and are marked with three dots on the case. The reason for that is some bad new style got out there that lose some of the black mat'l and could mess up your day if the junk clogged the carbs. So the latest new of that part no. have the three black dots to distinguish them. This is good news I think as doing the periodic check is a pain. Lucky us they are only about $180 for a set of four. Now if everyone knows this that's great, but just in case there it is.
Dick Seiders

dick seiders · #9 09-14-2016, 12:53 PM

For what it's worth I have already been told I will receive no refund on bad floats. I don't care! Just glad to have some that will last (hopefully).The irony of the whole deal is my original floats were ok, but those put into my carbs at insp/repair required the 25hr/60day routine. Go figure.
Dick Seiders

Ueli N · #10 07-18-2017, 04:01 PM

Trying to get the plane ready for first flight I checked the carbs and weight the floats.One carb. had floats weighing 4.6g and 3.9g total of 8.5g
The other carb. was 4.7g and 3.9g total of 8.6g.
I have less than one hour of run and taxi time on the engine. It seems to run fine on the ground.
Problem is, the floats are out of stock. CPS and Lockwood are out.
Is there anyone else I could check ?
I found someone that would fly off the phase one for me. Just hoping I won't be grounded for the rest of summer.
Any expert advice welcome! What do those numbers mean for someone with experience? Am I definitely grounded?

Ueli