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Carb Float Weight

todehnal

Well Known Member
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
 
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.
 
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?
 
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.
 
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
 
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-topmenu/expanded-video-instructions/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
 
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.
 
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
 
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
 
Heavy Floats

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
 
I assume the scale is still accurate, it was when I got it about 2years ago.
The floats were exposed to gas for about 7 month.
I ordered some floats from California Power Systems, they expect some shipment in on Friday. Keep my fingers crossed.
 
I assume the scale is still accurate, it was when I got it about 2years ago.
The floats were exposed to gas for about 7 month.
I ordered some floats from California Power Systems, they expect some shipment in on Friday. Keep my fingers crossed.


Did you get your floats ? I just got two pair from CPS today and they do not have any dots. In fact, each float in the pair of floats look to be different runs. Letters look different and the dates are differing. I'm not a trusting person and I tend to think CPS is sending me old stock ? I found it strange that Lockwood is out of stock and CPS had them.
 
I'm out of the country right now and won't be back until September 28.
But I got notified that the floats from CPS are on the way finally.
If it's still of value by then, I'll let you know what I received.

Ueli
 
Did you get your floats ? I just got two pair from CPS today and they do not have any dots. In fact, each float in the pair of floats look to be different runs. Letters look different and the dates are differing. I'm not a trusting person and I tend to think CPS is sending me old stock ? I found it strange that Lockwood is out of stock and CPS had them.

I also just received two pairs of floats (ordered from CPS last June). My old floats weigh in at over 8 grams. The engine runs fine. I did get a gas odor briefly on a couple of flights, during full power climb or throttle closure to descend. That's why I did a weight check.

The new floats are exactly as described above. Two floats marked differently in each pair. No dots. No brass sleeve apparent. Pair A weigh in at 6.33 gr. Pair B weigh in at 6.31 gr.

I tend to be suspicious also, but Rotax has changed the float design so many times I will give benefit of the doubt that these are, in fact, the latest design. For now at least.
 
I also just received two pairs of floats (ordered from CPS last June). My old floats weigh in at over 8 grams. The engine runs fine. I did get a gas odor briefly on a couple of flights, during full power climb or throttle closure to descend. That's why I did a weight check.

The new floats are exactly as described above. Two floats marked differently in each pair. No dots. No brass sleeve apparent. Pair A weigh in at 6.33 gr. Pair B weigh in at 6.31 gr.

I tend to be suspicious also, but Rotax has changed the float design so many times I will give benefit of the doubt that these are, in fact, the latest design. For now at least.

Thanks,
My new ones weigh 6.35 pair A and 6.27 pair B
Just got the scales so I don't know what the wet ones weigh yet. Weighed current wet before but the scales didn't go into the decimals (did show 3g each). One pair was very good 30cc on the flow test and the other was borderline 24cc. The 24cc drip tray is getting gas/fluid on it. I've yet to discover where the gas comes out of the carb to drip onto the tray. I "assume" a vent or something. Haven't looked it over much.
 
This carb float issue is getting a little old....have just over100 hours on the Hobbs, complied with the Rotax SB (changed out perfectly functioning floats); upon landing @ Glendale, AZ (trip from Coeur d' Alene, ID) found left carb profusely leaking fuel...yup, another heavy float issue.

$200+ and waiting for CPS to get a new set to me. Guess I'll add another set to my on-board emergency parts bag at this rate of usage before bad.
 
Ric,

Are you based at GEU for the winter? I?m at Desert Hangar Owners #3/24. If you see a silver Buick parked at either stop by.

Rich
 
Like I said above: My new ones weigh 6.35 pair A and 6.27 pair B

The pair I just pulled out that barely passed the CC flow test weigh 5.8 soaking wet :rolleyes::rolleyes::rolleyes::rolleyes::rolleyes:
 
Ric,

Are you based at GEU for the winter? I’m at Desert Hangar Owners #3/24. If you see a silver Buick parked at either stop by.

Rich

Will look for you....my buddy (partner in plane Joe) is in the mist of looking for someone to help him do a carb sync...I won't be down till latter half of Oct.

He wants to fly down to Ryan Field Tucson for the Rotax class Oct 14/15.. Mark Windslow (our fellow Hangar mate) stated he knew an RV-12 driver who he thought could help with carb sync...maybe they had you in mind��
 
Hey Ric - I think that will have been me :) good to meet you Mark and I are good friends and I am the guy over at deer valley with the RV12.

We should all meet up over at Glendale with Rich.

Julian
 
Hey Ric - I think that will have been me :) good to meet you Mark and I are good friends and I am the guy over at deer valley with the RV12.

We should all meet up over at Glendale with Rich.

Julian

Cool....looking foreword to it! I'm a breakfast kinda guy😜
 
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