The International Cessna^® 170 Association

While troubleshooting a slow leak in my carburetor, I came across Precision's Mandatory Service Bulletin MSA-13 "Replacement of Carburetor Floats With New Foam Floats" dated 1/30/2008. It replaced MSA-1 from 1990 which got rid of the old composite floats. It requires all floats to be updated to a new, blue, epoxy float by Dec. 31, 2008. Volare Carbutetors is part of the Tempest company, they bought out Precision Airmotive and have put out their own bulletin as well, Bulletin No. SB-2 released Feb. 1,2009 requiring the replacement by June 1, 2009. These can both be found here, along all the others ever put out on these carbs:

http://www.tempestplus.com/msacarburetorbulletins_.htm

Check the last page of the SB-2 for pictures of all different types of floats.

The SB applies to any Volare or it's predecessor's floats, to include Marvel-Schebler, Facet, and Precision Airmotive, it doesn't apply to carburetors containing floats manufactured by other FAA-PMA approved sources, if you can prove you have one of those. I doubt there's much difference between the brands myself. Here's a link to a letter Kelly put out on the subject:

http://www.kellyaerospace.com/service_p ... _float.pdf

So with the leak I have I decided to replace it. I pulled it yesterday and popped it open, the float I have is a plastic one, though the paperwork I have led me to believe I had a metal one. The "weld" joints at the top of the float appear cracked. I sank it in water overnight and it didn't leak a bit. But still doesn't look good to me, I'm glad I'm replacing it.
I ordered the float kit from A.E.R.O. in Granite City, IL 800-362-3044, around $130. A.E.R.O. is listed as one of Tempest's distributors. I also ordered a needle and seat kit, and they had the carb mounting gaskets as well.

Beware of float kits being sold by Spruce and everybody else. They're the old P/Ns which only bring you up to MSA-1 standards! I would also recommend if you're having your carb overhauled or exchanging it, to make sure it's going to have the new, blue floats in it.

Hopefully the combination of these will fix my problem.

Something else I learned, MSA-3 requires our carbs to be overhauled at engine overhaul or every 10 years whichever comes 1st. I've got a couple years to go or I would've gone this route.

I wouldn't be too quick to jump on any change we have been through this before.

Are we talking service bulletins or ADs. There is a difference in the compliance requirements when operating under part 91. As Mit mentioned, we've previously gone through the change the plastic float for brass before. Personally, I changed my plastic float for brass many years ago when California deleted MTBE as an oxygenator in Mogas and replaced it with Ethanol. Alcohol reacts with many plastics that are unaffected y gasoline.

Good point! They should have tested it with every available auto fuel blend and let us know they did before they put out the service bulletin!

Scott, TCM requires our engines to be overhauled chronologically (either/or 1800 operating hours.) You going to do that? (grin)

The point is, that unless the carb is giving you trouble, on a Part 91 airplane there's no requirement : to do anything with it (except drain it and clean the inlet screen during annual inspections.)

I do recommend overhauls simultaneously with the engine. Magnetos and other accessories too.

I know that these SBs aren't actually required, though I think it's important that everyone at least know they're out there. Which was my intent, not to tell everyone to do them. Also, I think it important that everyone knows to keep a little closer eye on the carb for any of the indications listed so they're not flying around with a bigger problem than they may think.

In my situation with a leaking carb, which is one of the indications of a possible leaking float, I decided to replace it. I went with the latest SB.

Also, I forgot to mention on my 1st post, on Tempest's website, on the Literature page, are the Service instructions for Carb Float Kit 666-1000. It has some good info and pics that could supplement an old carb service manual.

Is this the link t o which you were referring, Scott? (Thanks)

http://www.tempestplus.com/vE1000%20Word%2097-2003.pdf

Yep, that's it. Thanks George