Myself
manic mechanic
- Location
- Twin Lakes AR
Yep, that's correct. You're good to go! That other one will lead to fuel leakage and strange running problems.
FX-1 Chopping issue
- Thread starter Penguin
- Start date
E350
Site Supporter
- Location
- Sacramento Delta
@Myself I know that you are one of the professionals on this forum. Can we peel the onion a little farther on this matter?
If you take a look at the Super BN 44 Diagram on the left and the Super BN 38 on the right, you will notice that the SBN44 does not have grooves for the Rubber Oring to go into. Instead the SBN44 uses the paper gasket (which I put on top of the photo below).
But the SBN38 has the grooves and uses the Rubber Oring in the diagram.
BUT MY SBN44 HAS THE GROOVES AND USES THE RUBBER ORING !!!! (And thus the diagram is wrong for my SBN44.)
Did Yamaha make this change to their version of the SBN44 ?
Or did Mikuni update the SBN44 to the design of the SBN38 somewhere along the way? And just not update their diagram?
My oem Yamaha Service Manual for the FX-1 and Super Jet SJ700 1994-1995 SHOW THE RUBBER ORING:
What gives?
I have been using oem looking engine compartment fuel filters. But apparently these will separate at the glue line between the two pieces. No doubt letting in air at that junction could cause a fuel starvation at WOT. While working on the ski I likely caused it to separate completely.
I just added a OEM Yamaha FX-1 fuel filter to my order of an oem Mikuni SBN44 rebuild kit from Chris @JetManiac
Ski runs great on the trailer. Will test ride in water today.
If you take a look at the Super BN 44 Diagram on the left and the Super BN 38 on the right, you will notice that the SBN44 does not have grooves for the Rubber Oring to go into. Instead the SBN44 uses the paper gasket (which I put on top of the photo below).
But the SBN38 has the grooves and uses the Rubber Oring in the diagram.
BUT MY SBN44 HAS THE GROOVES AND USES THE RUBBER ORING !!!! (And thus the diagram is wrong for my SBN44.)
Did Yamaha make this change to their version of the SBN44 ?
Or did Mikuni update the SBN44 to the design of the SBN38 somewhere along the way? And just not update their diagram?
My oem Yamaha Service Manual for the FX-1 and Super Jet SJ700 1994-1995 SHOW THE RUBBER ORING:
What gives?
I have been using oem looking engine compartment fuel filters. But apparently these will separate at the glue line between the two pieces. No doubt letting in air at that junction could cause a fuel starvation at WOT. While working on the ski I likely caused it to separate completely.
I just added a OEM Yamaha FX-1 fuel filter to my order of an oem Mikuni SBN44 rebuild kit from Chris @JetManiac
Ski runs great on the trailer. Will test ride in water today.
Last edited:
Myself
manic mechanic
- Location
- Twin Lakes AR
The early 90's SBN44 were flat inside with NO groove for the o'ring. Seems like 93-94 were hit-n-miss on that style VS the o'ring style. By 95 they ALL had the o'ring style. Not just Yamaha, I'm talking Tigershark and Wet Jet too. Of course, you never know on these things who's messed with what and if the carb is even original to the machine anymore. My thought on the change is that the bodies are cast and not perfectly flat inside. This would lead to leakage around the gasket in a short amount of runtime hours.........heat/cool cycles. The o'ring can make up for those casting imperfections and remained sealed for a VERY long time.