Author Topic: LeMans 3 - leaky carb  (Read 803 times)

Offline Vince in Milwaukee

  • Gaggle Hero
  • *****
  • *
  • *
  • Posts: 3677
  • Location: Kenosha, WI
LeMans 3 - leaky carb
« on: June 10, 2019, 05:12:17 PM »
Looking for some help for a leaky carburetor on my LM3.  Installed a new float needle and seat (this has fixed the problem in past years), but it still leaks gas, although not as badly.  Tips / advice most appreciated as we've finally got some nice riding weather here in Wisconsin.   
1984 Moto Guzzi 850 LeMans III, 1986 California II
Gone but not forgotten:
1969 Moto Guzzi Ambo, 1994 BMW K75RTw/ABS, 1996 BMW R1100RT, and 1993 BMW K75

Offline Chuck in Indiana

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • Posts: 29453
Re: LeMans 3 - leaky carb
« Reply #1 on: June 10, 2019, 05:19:40 PM »
Float height set properly?
Chuck in (Elwood) Indiana/sometimes SoCal
 
87 AeroLario
95 Skorpion tour
22 Royal Enfield Classic 3 fiddy
 "Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."
Albert Einstein

Offline Guzzidad

  • Gaggle Mentor
  • ****
  • *
  • Posts: 814
  • Location: Tampa, FL
Re: LeMans 3 - leaky carb
« Reply #2 on: June 10, 2019, 06:38:49 PM »
   What Chuck said. I just had to replace 2 floats because they filled with gas.

Offline sdcr

  • Gaggle Hero
  • *****
  • *
  • Posts: 1994
  • Location: Pennsylvania
Re: LeMans 3 - leaky carb
« Reply #3 on: June 10, 2019, 07:07:45 PM »
Over the years, I've had to renew the float bowl nut gasket a few times.
John
2000 BMW R1100 RS
1983 BMW R100
2009 Jaguar XK

Wildguzzi.com

Re: LeMans 3 - leaky carb
« Reply #3 on: June 10, 2019, 07:07:45 PM »

Offline guzzista

  • Gaggle Hero
  • *****
  • Posts: 1049
  • Location: SF Bay Area
Re: LeMans 3 - leaky carb
« Reply #4 on: June 10, 2019, 07:30:57 PM »
Other places I have had leaks . 1: banjo fitting.  The 6mm fiber  washer  can  allow leakage if not replaced. I like to add a  aluminum washer  as well on the outside of the aforementioned washer , particularly on the left side carb where the access is  more limited and the view not as good. 2.  The bowl O ring even if this may be a no brainer to seasoned guzzisti. The recent ones I have come across seem to harden sooner due to ethanol fuel. Combined  with  a squished bowl nut washer, makes leakage more likely.

http://www.mgcycle.com/index.php?main_page=product_info&cPath=34&products_id=1500
1975 750S Tribute bike, 1994 Cali 1100, 2007 Ducati GT1000, 1983 SP1000, 1973 V7Sport project, 2017 California1400 Touring

Offline wirespokes

  • Gaggle Hero
  • *****
  • Posts: 2028
Re: LeMans 3 - leaky carb
« Reply #5 on: June 10, 2019, 08:54:22 PM »
That pretty well covers it except for the fuel line. They tend to age right at the point where they attach. Snipping off a quarter or half an inch usually fixes.

Offline SED

  • Gaggle Hero
  • *****
  • *
  • *
  • Posts: 1627
Re: LeMans 3 - leaky carb
« Reply #6 on: June 10, 2019, 11:32:42 PM »
Check that the float is not hanging up on the pivot or its supports.  I installed new plastic floats and one started to hang up after a few months.  Trimming the edge of the float pivot solved it.
1983 LeMans III
1981 Monza
1947 Ariel Red Hunter
1939 Ariel Red Hunter
1937 Guzzi GTV

 

20 Ounce Stainless Steel Double Insulated Tumbler
Buy a quality tumbler and support the forum at the same time!
Better than a YETI! BPA and Lead free.
Advertise Here