01-30-2009, 11:00 PM #1
Can you see a problem in this picture?
See if you can spot the problem, this is a SBN-I fuel pump from a GPR. Pics of both sides of pump.
01-30-2009, 11:04 PM #2
I can't see any creases...the check stays seem to be ok. What I am not seeing?
01-30-2009, 11:05 PM #3
01-30-2009, 11:53 PM #4
Look at the check valves closely
01-30-2009, 11:55 PM #5
01-31-2009, 12:05 AM #6
By the looks of it, maybe an external fuel pump check valve on a piggied fuel pump? If I worded it right. Bill that second pic might not be at a good angle. if not that maybe the check valve is in backwards. I heard thats what the line on a new one is for. Just thoughts........
01-31-2009, 12:13 AM #7
Size matters. The first pic has two different check valves installed, one from a SBN carb the small 18mm dia one, and the correct one from a SBN-I carb 20 mm in dia. the pic a few posts down shows what we are used to seeing in the SBN carbs creased check valves. The diameter of the sealing surface in the fuel pump is the same in both carbs but the later models went to larger check valves. It is rare to find a creased check valve on the SBN-I carbs.
The shop that supposedly rebuilt these carbs recently did not understand or notice the difference.
pics of both fuel pumps SBN on left SBN-I right
01-31-2009, 12:20 AM #8
They also use the bigger 20mm check valves in the remote/external fuel pumps? Or they another size?
01-31-2009, 12:26 AM #9
I have not worked on any remotes so I can't answer that. I tried to fit the 20mm check valves in the SBN carbs just for an experiment and they will barely fit in the diaphram side but will not fit in the body side. I am thinking about clearancing it a bit and testing them out.
Pic of 20mm check in SBN pump
01-31-2009, 12:27 AM #10
I was gonna say that!!!
no, I was 'nt
Nice catch Bill....who re-built them? Or do we need to say?
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By Pale Rider in forum Yamaha Open DiscussionReplies: 4Last Post: 08-05-2010, 12:44 PM
By boocat in forum Yamaha PWC Performance (2-stroke)Replies: 7Last Post: 08-21-2008, 10:38 PM
By spyder3000gtvr4 in forum Yamaha How To & FAQsReplies: 1Last Post: 08-21-2007, 05:29 PM
By JAG in forum 4-Tec PerformanceReplies: 22Last Post: 07-04-2007, 06:30 PM
By WATER BONER in forum Open DiscussionReplies: 45Last Post: 09-10-2006, 09:30 PM