Brass clunk in gas fuel.  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Gas Engines >> Brass clunk in gas fuel.
Page: [1] 2   next >   >>  

Login
Message << Older Topic   Newer Topic >>
Brass clunk in gas fuel. - 5/13/2008 9:28:00 PM   
karolh


 

Posts: 2142
Joined: 5/15/2002
From: Mandeville, JAMAICA
Status: offline 		While flying my gas model on the weekend I noticed bubbles in the carb's feed line and decided to redo the tank plumbing. On inspection of the tank etc I found that the brass clunk used as a weight on the fill line in my 3 line system was covered in a dark sticky oil like goo, which was also in spotty patches on the sides and bottom of the tank.

My first impression was that the tank stopper was disentegrating, but on removal I found it to be intact. No where else in the tank was affected including the felt clunk. Thank goodness I used one which I'm sure is what kept the goo out of the carb.

I am wondering if the Bel Ray MC-1 oil/ gas combination I use could in any way be contributing to this happening. Of note is the fact that the goo washed off fairly easily with gas. What are your thoughts on this.

Karol
       Post #: 1

RE: Brass clunk in gas fuel. - 5/13/2008 10:08:47 PM   
pe reivers



Posts: 2501
Joined: 1/23/2002
From: Arcen, , NETHERLANDS
Status: offline 		do not use a brass clunk. Use only felt clunks or other fine mesh filters.
Not because brass is no good, but because you should filter all fuel that goes to the carb well. (rule #1 in gas engines)

_____________________________

Pe, Dealer for MVVS, MTW and Mejzlik; www.mvvs.nl
There is sanctuary in analisys.

(in reply to karolh)
       Post #: 2

RE: Brass clunk in gas fuel. - 5/14/2008 12:36:01 AM   
Tired Old Man


 

Posts: 11367
Joined: 2/25/2002
From: Central, CA, USA
Status: offline 		Concur

_____________________________

If you can''''t fix it with a hammer, you have an electrical problem.

(in reply to pe reivers)
       Post #: 3

RE: Brass clunk in gas fuel. - 5/14/2008 1:15:43 AM   
altavillan


 

Posts: 1032
Joined: 10/24/2004
From: Altaville, CA, USA
Status: offline 		Other than that, your fuel probably has alcohol in it. It attracts water and then the brass starts to grow the crud you mentioned. When folks start rioting over the price of corn tortillas and suger they'll stop putting it in our gas. But then older big block engines run well on it and so do our gas engines. Put a good filter anywhere you want it as long as you have one. The paper filtered clunks are nice though, they are heavy enough to follow the gas around, but are limited to a 3 line system and they present their own set of problems.

_____________________________

I didn''t put the bullet in the fire and you quit talking about my mother! "Cosby, Shop Class, 1968 or so"

(in reply to Tired Old Man)
       Post #: 4

RE: Brass clunk in gas fuel. - 5/14/2008 1:18:17 AM   
karolh


 

Posts: 2142
Joined: 5/15/2002
From: Mandeville, JAMAICA
Status: offline 		Pe,

If you read my post carefully you will see that the brass clunk is used only as a weight on the fill line in the tank, and that I do in fact use a felt filter on the feed line to the carb.

Pat,

I was hoping for a more indepth response from you.

So far no one has addressed my only concern, which is simply what are the possibilities as to what might have caused the goo on the clunk and on the sides of the tank.

Karol

(in reply to pe reivers)
       Post #: 5

RE: Brass clunk in gas fuel. - 5/14/2008 1:29:51 AM   
altavillan


 

Posts: 1032
Joined: 10/24/2004
From: Altaville, CA, USA
Status: offline 		Methanol attracts water, the brass probably has impurities in it that react to water. the spots around the tank are from the brass sitting in one place for extended periods of time. Solution> FLY MORE!!!

_____________________________

I didn''t put the bullet in the fire and you quit talking about my mother! "Cosby, Shop Class, 1968 or so"

(in reply to karolh)
       Post #: 6

RE: Brass clunk in gas fuel. - 5/14/2008 2:03:31 AM   
karolh


 

Posts: 2142
Joined: 5/15/2002
From: Mandeville, JAMAICA
Status: offline 		What sort or type of weighted clunk would you suggest as a replacement for the brass.

Karol

(in reply to altavillan)
       Post #: 7

RE: Brass clunk in gas fuel. - 5/14/2008 4:15:20 AM   
tomriddle



Posts: 354
Joined: 8/22/2004
From: Woodbridge, VA, USA
Status: offline 		""Pat, I was hoping for a more indepth response from you. ""


Pat,

Apparently your public demands MORE!!

(too good to pass up)!!

Seriously, thanks for all the posts that you share your experiences on - I am impressed that you get to as many as you do.

tom

_____________________________

"Life is tough;
but its tougher when you're stupid!"

(in reply to karolh)
       Post #: 8

RE: Brass clunk in gas fuel. - 5/14/2008 4:17:48 AM   
RTK


 

Posts: 3911
Joined: 4/20/2003
From: CENTRAL , CA, USA
Status: offline 		If it were me, I would go with a two line system. Use a small automotive paper filter on filling jug out put line and a felt clunk for the tank. Has worked well for me over the years, KISS

(in reply to karolh)
       Post #: 9

RE: Brass clunk in gas fuel. - 5/14/2008 4:48:50 AM   
altavillan


 

Posts: 1032
Joined: 10/24/2004
From: Altaville, CA, USA
Status: offline 		Something with chrome plating should do it.

_____________________________

I didn''t put the bullet in the fire and you quit talking about my mother! "Cosby, Shop Class, 1968 or so"

(in reply to karolh)
       Post #: 10

RE: Brass clunk in gas fuel. - 5/14/2008 5:47:03 AM   
Tired Old Man


 

Posts: 11367
Joined: 2/25/2002
From: Central, CA, USA
Status: offline 		Sorry but the photo I needed for more input was on a different laptop and I wasn't where it was at the time. Brass reacting with residual oil after a prolonged period sitting in an empty tank does that. I use what's in the picture. It will work up to at least a 115cc engine and probably a lot more. You can't get any more fuel in a carb than what the size of the carb inlet permits and this filter equals or exceeds the size of most carb inlets. Just like fuel tubing, where anything larger than the medium stuff is a waste of money.

This filter has a nasty habit of eliminating bubbles in the fuel line and picking up every last drop of gas before the engine runs dry I use one in the gas can and one in the plane. Don't need no stinking paper filters

Attachments
Click to see fullsize image.
Click for fullsize


_____________________________

If you can''''t fix it with a hammer, you have an electrical problem.

(in reply to altavillan)
       Post #: 11

RE: Brass clunk in gas fuel. - 5/14/2008 7:47:06 AM   
fokker fan



Posts: 53
Joined: 11/17/2006
From: Christchurch, NEW ZEALAND
Status: offline 		That's what I use too

(in reply to Tired Old Man)
       Post #: 12

RE: Brass clunk in gas fuel. - 5/14/2008 1:08:51 PM   
karolh


 

Posts: 2142
Joined: 5/15/2002
From: Mandeville, JAMAICA
Status: offline 		Thanks to all who responded.


Pat,

My faith has been restored

Karol

(in reply to fokker fan)
       Post #: 13

RE: Brass clunk in gas fuel. - 5/15/2008 3:11:01 AM   
Nogyro



Posts: 1917
Joined: 11/30/2001
From: Puryear, TN, USA
Status: offline
quote:

ORIGINAL: Pat Roy

This filter has a nasty habit of eliminating bubbles in the fuel line and picking up every last drop of gas before the engine runs dry


That's the same felt filter that I've always used as well.

I can back Pat's statement up about this type of clunk eliminating bubbles and sucking ALL the fuel out of your tank. You get no warning when the engine is going to run dry. It's ugly when you're in a TR at 50 ft.



_____________________________

Frank

(in reply to Tired Old Man)
       Post #: 14

RE: Brass clunk in gas fuel. - 5/15/2008 3:34:57 PM   
karolh


 

Posts: 2142
Joined: 5/15/2002
From: Mandeville, JAMAICA
Status: offline 		Decided to use a felt clunk on the fill line so hopefully that will be the end of that particular problem. Now I gotta go check that 'other' tank with a similar arrangement. Any bets on what I will find ?? Thanks all.

Karol

(in reply to Nogyro)
       Post #: 15

RE: Brass clunk in gas fuel. - 5/16/2008 2:35:22 AM   
TheRickster



Posts: 73
Joined: 4/29/2004
From: Beaumont, TX, USA
Status: offline 		If it is a problem with your fuel attacking the brass then what are you going to do about the brass tubes in the tank? I have always ran a heavy clunk that will follow the fuel in the tank and never had any funky growth in the tank.. Maybe I am just lucky.. I run two lines. A vent to the top and a clunk line. I put a large ID brass "T" in the fuel line in route to the carb and off the "T" run a fuel DOT or a line with a plug in it.. Fuel and defuel all through that line...

K.I.S.S.

Rick

_____________________________

We do not do this to save money, we save money to do this..

(in reply to karolh)
       Post #: 16