BritBike Forum logo
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
  JWood Auction  
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons, "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Photo posting tutorial

Member Spotlight
Coco
Coco
Regina Sk, Canada
Posts: 358
Joined: May 2007
Show All Member Profiles 
Shout Box
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Who's Online Now
209 registered members (57nortonmodel77), 1,646 guests, and 556 spiders.
Key: Admin, Global Mod, Mod
Newest Members
revans, Gilly, XTINCT, Bruce Roberts, Brian Ellery
9959 Registered Users
Top Posters(30 Days)
btour 193
koan58 99
Stuart 84
NickL 73
Popular Topics(Views)
438,944 mail-order LSR
Forum Statistics
Forums33
Topics65,290
Posts632,453
Members9,959
Most Online3,995
Feb 13th, 2017
Like BritBike.com on Facebook

Previous Thread
Next Thread
Print Thread
Rate This Thread
#584263 - 02/05/15 9:05 pm Ethanol laced gas and Amal floats  
Joined: Aug 2001
Posts: 3,871
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member

Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
I was out starting my Lightning yesterday and while it started OK, it ran real crappy. Pretty easy to diagnose as the left side was very rich. Upon disassembly of the carb I found the AMAL float (a white one) was half full of fuel. I swapped it out and the bike ran good. This is the third float that has leaked in one of my bikes in the past 8-10 years.....all on different bikes. Is this an ethanol gas thing or just lousy AMAL floats? Do I need to go to the newer black floats at about $18 a pop.

Mr Mike

Last edited by Mr Mike; 02/05/15 9:06 pm.
Support Your #1 BritBike Forum!
Membership Type! Free
Member
Premium
Member
Premium Life
Member
Vendor
Member
Site
Sponsor
Recognition No Premium Member Premium Life member (5 years) Vendor Member Site Sponsor Membership
Post commercial threads No No No Yes Yes
Custom title No Yes Yes Yes Yes
Upload avatar & photos No Yes Yes Yes Yes
Link avatar & photos Yes Yes Yes Yes Yes
Private Message Storage: 10 100 100 100 100
Length of signatures 255 600 600 600 600
Removes this very advert island between post 1&2 No Yes Yes Yes Yes
Price Free $12.90/year $105.00 No End
$55.00/5 years
$210.00/year
($17.50/month)
Email
Click on button >>
  Premium Member Premium Life member Vendor Member Site Sponsor Membership
#584266 - 02/05/15 9:30 pm Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Sep 2008
Posts: 710
Blown Income Online content
BritBike Forum member
Blown Income  Online Content

BritBike Forum member

Joined: Sep 2008
Posts: 710
Edgewater, Md
Upgrading to a stay up float would be best. I have yet to do this on any of mine but I am using the original AMAL floats and I also turn the petcocks off and let the bike run itself out of fuel.


1955 BSA Bantam D1 Plunger
1956 BSA A10RR Street and LSR Bike
1961 BSA C15S
1966 BSA spitfire
1969 Triumph T100C
1970 Triumph TR6R
1972 BSA Lightning LSR Bike
1974 Triumph T150V
#584269 - 02/05/15 9:40 pm Re: Ethanol laced gas and Amal floats [Re: Blown Income]  
Joined: Feb 2014
Posts: 744
zoe Offline
BritBike Forum member
zoe  Offline
BritBike Forum member

Joined: Feb 2014
Posts: 744
US
I was told to run ethanol free fuel whenever possible so I do and I have had no float problems running black AMAL floats.

#584335 - 02/06/15 2:53 pm Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Mar 2006
Posts: 1,164
htown Online content
BritBike Forum member
htown  Online Content
BritBike Forum member

Joined: Mar 2006
Posts: 1,164
Magnolia, TX
Good luck finding ethanol free gas in most areas. I have stay-up floats in the three Brit bikes I currently have on the road. They are also easier to adjust the fuel level.


1978 Bonneville T140E
1974 Trident
1970 BSA Thunderbolt
1971 Norton Commando
1972 Norton Commando
2-1974 Norton Commandos
2004 XL 1200R Sportster

Everything will be alright in the end. If its not alright, its not the end.
#584346 - 02/06/15 3:37 pm Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Feb 2008
Posts: 4,049
Tridentman Online content
BritBike Forum member
Tridentman  Online Content

BritBike Forum member

Joined: Feb 2008
Posts: 4,049
New Jersey USA
The "stay up" float is not hollow like the yellow ones. It is a "closed cell foam" where there are lots of air bubbles not connected together. It was developed in UK for the British Army so that nasty fuels (like ethanol) could not make the float sink.
Not too sure what the effect is of ethanol on the yellow plastic floats but there have been reports of the ethanol affecting them adversely.
Good policy to fit the stay up floats IMHO.
As for being easier to adjust the fuel level--this can be true but our moderator (JH) believes that this affects the sensitivity of the float and therefore the level operation--for reasons which make sense to me.
HTH

#584398 - 02/07/15 3:03 am Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: May 2013
Posts: 4,533
Allan Gill Offline
Allan Gill  Offline



Joined: May 2013
Posts: 4,533
Rotherham - S. Yorkshire
I have to agree with JH's beliefs on the sensitivity of these floats.

With the work I have done in my own bike it will run very rich if you don't control it correctly, when last ran it was running a lot richer on the left pot, however the float heights were set the same with the stayup float ( note that unlike the older float bowls the brass seat us now non adjustable in the newer units). As an experiment I have swapped around the float bowls and floats to the other carb (being twin carb) to see if the richness changes sides ( proving the float hight causing richness and not difference in port size). As a last resort I will switch to the White plastic floats which are yet to cause me a problem.


beerchug
#584461 - 02/07/15 5:23 pm Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Mar 2006
Posts: 1,164
htown Online content
BritBike Forum member
htown  Online Content
BritBike Forum member

Joined: Mar 2006
Posts: 1,164
Magnolia, TX
I set mine using the u-tube method. AMAL recommends a fuel level of .17 to .24 below the top of the float bowl. I found that my bike runs best and has best plug color(not that reliable with today's gas) at the bottom number or just a hair below. Towards the .17 side was too rich. You need to experiment a little to find each bikes comfort zone.

Last edited by htown; 02/07/15 5:32 pm.

1978 Bonneville T140E
1974 Trident
1970 BSA Thunderbolt
1971 Norton Commando
1972 Norton Commando
2-1974 Norton Commandos
2004 XL 1200R Sportster

Everything will be alright in the end. If its not alright, its not the end.
#584499 - 02/07/15 9:50 pm Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Oct 2006
Posts: 2,309
Irish Swede Online content
BritBike Forum member
Irish Swede  Online Content
BritBike Forum member

Joined: Oct 2006
Posts: 2,309
Elburn, Ill. USA
Although the word "Concentric" is not used in any of the above posts, I assume they have the float problem being discussed here.

If you are working with MONOBLOCS, please note that the early ones had BRASS floats, and these do turn up at swap meets.

I have yet to see any gas or ethanol that will dissolve BRASS.

#584518 - 02/08/15 1:05 am Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Aug 2014
Posts: 309
John Goodwin Online content
BritBike Forum member
John Goodwin  Online Content
BritBike Forum member

Joined: Aug 2014
Posts: 309
Bowral NSW Australia
I have a real concern about the fuels we have to buy these days as I patiently wait for at least one of my Spitfires to turn up. Both of which in original trim have glass tanks.
I've done many searches to try and find out if any of the fuels here in Australia are ethanol free, but cannot find any definitive information about ethanol contents other than our E10 fuels here.
The only article I could find of any help was this one
http://www.roadrider.com.au/gear-reviews/the-fuel-truth
Sadly it doesn't seem overly encouraging about the use of Shell V Power which was until now going to be the fuel of my choice.
Even worse is the viability of storing modern fuels, from what I read, 4-8 weeks is about it which isn't a long time to store fuels.
Guess it beats no fuel at all


Current: 2 x 1966 A65S, 1 x 1967 A65SA, 1 x 69/70? A65LA space Y, 1 X D14/4 & 1 x B175
Past: 4 x 1976 T160V, 1 74/5 T150V, 83 model GSX 750 ESD, Z650, Katana 1100(Bathurst Model), 79 T140V, 70's TR6, 2 x 1971 BSA 250 Gold Stars, 50's 350 Goldie, A65 Spitfire semi basket case, 1965/6? A65 LC, Tiger 21 350 & a D14/4 Bantam, 175 Bridgestone Twin with Zimmerman discs!
#584519 - 02/08/15 1:15 am Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Jan 2014
Posts: 3,324
NickL Online content
BritBike Forum member
NickL  Online Content
BritBike Forum member

Joined: Jan 2014
Posts: 3,324
Aus
Most blokes here tend to use BP 'Ultimate', I just use anything 98 RON. Don't store it, it goes off.



#584573 - 02/08/15 11:34 am Re: Ethanol laced gas and Amal floats [Re: htown]  
Joined: Aug 2001
Posts: 3,871
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member

Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
Originally Posted By htown
I set mine using the u-tube method. Amal recommends a fuel level of .17 to .24 below the top of the float bowl. I found that my bike runs best and has best plug color(not that reliable with today's gas) at the bottom number or just a hair below. Towards the .17 side was too rich. You need to experiment a little to find each bikes comfort zone.


I did some rather extensive utube testing last year on fuel level. I learned that setting fuel height within fractions of an inch or a few thousandths is likely unnecessary. If you get the level too high the carb will inadvertengly flood due to vibration and/or pther things depending on whether the bike is actually level when riding. It seems relatively unaffected by setting it too low. I also concluded that the black floats with the adjustable tangs are probably what AMAL should have used all along. Most carbs have a float with an adjustable tang. To adjust float height by moving a pressed in needle seat was likely not intended to be an adjustment. I have found that you can get excellent performance by adjusting the things that are meant to be changed or adjusted...ie needles, needle position, needle jet, main jet, pilot jet and slide. And with the black floats you have a simple easy float height adjustment. The AMAL Concentric is a very cheap to manufacture carb with a lot of flexibility. With judicious tuning they can be made to work very well on a variety of applications.

Mr Mike

#584574 - 02/08/15 11:37 am Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: May 2013
Posts: 4,533
Allan Gill Offline
Allan Gill  Offline



Joined: May 2013
Posts: 4,533
Rotherham - S. Yorkshire
Never had any issues with v power in the UK. The "yellow" which is mentioned in this article I have yet to find in any UK fuels, however I have found most fuels when used on the continent do have this yellow ness to them. The result is usually stained on the crankcases following flooding of the Carburetor


beerchug
#584579 - 02/08/15 11:53 am Re: Ethanol laced gas and Amal floats [Re: htown]  
Joined: May 2013
Posts: 4,533
Allan Gill Offline
Allan Gill  Offline



Joined: May 2013
Posts: 4,533
Rotherham - S. Yorkshire
Originally Posted By Mr Mike
Originally Posted By htown
I set mine using the u-tube method. Amal recommends a fuel level of .17 to .24 below the top of the float bowl. I found that my bike runs best and has best plug color(not that reliable with today's gas) at the bottom number or just a hair below. Towards the .17 side was too rich. You need to experiment a little to find each bikes comfort zone.


I did some rather extensive utube testing last year on fuel level. I learned that setting fuel height within fractions of an inch or a few thousandths is likely unnecessary. If you get the level too high the carb will inadvertengly flood due to vibration and/or pther things depending on whether the bike is actually level when riding. It seems relatively unaffected by setting it too low. I also concluded that the black floats with the adjustable tangs are probably what AMAL should have used all along. Most carbs have a float with an adjustable tang. To adjust float height by moving a pressed in needle seat was likely not intended to be an adjustment. I have found that you can get excellent performance by adjusting the things that are meant to be changed or adjusted...ie needles, needle position, needle jet, main jet, pilot jet and slide. And with the black floats you have a simple easy float height adjustment. The AMAL Concentric is a very cheap to manufacture carb with a lot of flexibility. With judicious tuning they can be made to work very well on a variety of applications.

Mr Mike


Mr Mike, how do you explain setting the float height when the carbs were originally distributed with plastic unbendable floats.

Originally Posted By htown
I set mine using the u-tube method. Amal recommends a fuel level of .17 to .24 below the top of the float bowl. I found that my bike runs best and has best plug color(not that reliable with today's gas) at the bottom number or just a hair below. Towards the .17 side was too rich. You need to experiment a little to find each bikes comfort zone.


Bout time I made a rig to set my float heights, have you tried the effects on float height with different fuel head hight or weight?


beerchug
#584649 - 02/08/15 10:40 pm Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Aug 2001
Posts: 3,871
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member

Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
Hey Alan,
I think that fuel level height was something that AMAL chose not to have an adjustment for. If the float, seat, and needle are all within specs, they should deliver a fairly uniform fuel height. You never see that seat adjustment in the AMAL guides, but tuners figured out you could change the fuel height by moving the needle seat. In general the fuel level will vary depending on the depth of the needle seat, the length of the needle and the tab on the float. I measured a number of bowls and found the seats are very close to the same heights when the shoulder is on the casting . The needle lengths I measured were all within a couple of thousandths. The white floats did vary some. Some had what JH has referred to as a "drooping tab" (defect). These made a very measurable difference in fuel height(lower)because I had one. If you get the fuel height too high using a black float the float can foul on the top of the body and not shut off. I set my height at about 5/16ths to 3/8ths below the joint surface so I was sure it would not foul the float and stay open. When I tried to set it at the higher end of the .017-.024" range, it was very close to fouling the float on the top of the carb. The bike started well and ran well. Spark plugs were clean at both idle and at cruising. The black floats are similar to brass floats used on many carbs. The adjustable tang has been around since very early carburettors. I am NOT saying that fuel level does not make any difference. It does, but it is not huge, and with all the adjustments (slide, needle position, needle jet, mail jet, pilot jet) available on a simple AMAL it is easy to correct the mixture for smooth running.

I'm sure others will disagree with me on the importance of fuel height but I have always been able to adjust a carb to deliver the right mixture...well except for my first bike. At that time I didn't know there were different jets, slides and needles. I had a 250 that would foul the plug in 100 miles. I shimmed up the needle jet with a washer to lean it out. It worked and then someone told me about the notches and clip in the needle. Back then I didn't have a manual or anything else but did whatever it took to have a ride. I am sure that there were others that didn't know "jack" about their rides as youngsters.

Cheers,

Mr Mike

Last edited by Mr Mike; 02/08/15 10:43 pm.
#588325 - 03/03/15 3:34 pm Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Feb 2007
Posts: 2,200
Semper Gumby Offline
BritBike Forum member
Semper Gumby  Offline
BritBike Forum member

Joined: Feb 2007
Posts: 2,200
Atlanta, GA USA
Found my Firebird was idling on the LH carb only because the fuel level was too low in the RH carb (8mm) had to tap the seat down to get the fuel level up to 6mm. Idles on both carbs now.

I put a brass tube into a float bowl drain and attached some clear plastic tubing to make a fuel level tool. Works nice - easy to make.


Gaggle of BSAs
a Honda
an old BMW
and a Montesa
Parking lot Elf in training
#588437 - 03/04/15 10:11 am Re: Ethanol laced gas and Amal floats [Re: Mr Mike]  
Joined: Nov 2011
Posts: 80
GreenMonster Offline
BritBike Forum member
GreenMonster  Offline
BritBike Forum member

Joined: Nov 2011
Posts: 80
NH
Mr. Mike :

Been a long time since we have chatted, how have you been?

Well figured I would lend a little advice hear. I also own a Kawasaki Concours and one of the things, that we do to help alleviate the issues caused by alcohol is we dope our fuel with TCW3 spec 2 stroke oil mainly Pennzoil.

It works wonders to prevent sticking, corrosion and helps add some lubricity.

It won't prevent the fuel from attacking the old float's so a newer float will be needed.

I have run Marvel Mystery Oil in my fuel for years also but, it does not have the lubricity that the TCW3 has.

General rule of thumb is 1 oz per 4 gallons for the TCW3 and 2 oz's for the Marvel.


Never Allow The Radical Views Of The Few To Infringe On The Constitutional Rights Of The Many

Moderated by  Allan Gill, Jon W. Whitley 


Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
UBB.threads™ PHP Forum Software 7.6.0
Page Time: 1.954s Queries: 15 (0.030s) Memory: 0.9218 MB (Peak: 1.1828 MB) Zlib disabled. Server Time: 2017-11-23 14:57:59 UTC