Brandon, a couple of notes for those following your procedure: 1 - Only use genuine Mikuni parts. Aftermarket Mikuni "compatible" kits are well known in the PWC world to not work correctly and can cause a lean condition that will blow up your engine. 2 - The "Phillips" screws inside the Mikuni carburetors are actually not Phillips but are JIS (Japanese Industrial Standard). Using a standard Phillips screwdriver risks stripping out the heads of the screws. For about $11.00 you can get the Vessel brand JIS driver from Amazon when you order the carb kit and its tip fits the screws much better than a Phillips tip will. 3 - An economical ultrasonic cleaner would be worthwhile for cleaning carburetors. You can use the same cleaning solvent you use now, it just works better with a bit of heat and vibration. A 3 litre ultrasonic is a good size for cleaning these Mikuni carbs. I have heated the same carb cleaner you use up to 40 deg C with no issue and it works much better/faster for cleaning (20-30 minutes as opposed to overnight). 4 - Re-use the original needle spring when rebuilding the carburetor. There four several different spring strengths that Mikuni installed in their carbs and the new one that comes in the kit is probably not the same as the original. As long as it is in good condition, the original will generally work better. 5 - Make sure you test the pop-off pressure of the needle and seat after you re-assemble them. A too high of pop-off pressure can cause a lean condition and too low of a pop-off pressure can make your engine run rich. Neither of these conditions is desirable. You can get a pop-off tester on Amazon or e-bay for not too much money. It is essentially a small hand air pump and pressure gauge that you use to pressurize the supply side of the carburetor. A small squirt of WD-40 on the back side of the needle is used to give a clean pop (back side is where the arm attaches). Careful not to be looking at the needle directly when it pops because it will spray the WD-40 when the spring is overcome. Mikuni pop-off pressures for specific applications are available online. 6- There is a very good Mikuni user manual available on the Mikuni USA site, it has an exploded view and tuning information and instructions on rebuilding these carburetors. Other than these notes, great video
Other than the video, great notes! I should have reused the original spring, I told myself I was going to, and you see where that got me. Also, this was a genuine kit. Couldn't find a BN manual, only an SBN - probably good enough though.
@@BrandonsGarage I believe the BN and SBN are fairly close. At least close enough to give an idea of how the carbs work and some of the gotchas to look out for.
Hey there, I'd like to pick up one of those JIS screwdrivers for rebuilding my BN34 carb....not really sure what size screwdriver to order though? I assuming the screws in the carb are pretty small....any guidance you can give me on the right size for the screwdriver?
HDMFly the JIS screwdriver I used is the same size as a no.2 Phillips. The one I purchased is the Vessel Megadora 900 +2x100 JIS cross point on Amazon. Hope this helps.
I remember using the standup Kawasaki a lot when I was a teenager. Knee punisher and fatigue maker is what I remember of it, and it would be doubly so now in getting near middle age. The silver lining memories though were late June or July immediately at legal PWC daylight on the water where it was pure glass smooth water on that machine.
Pretty involved carb. It's a good bad thing when it comes combining the carb and fuel pump. Ran good on the water. Kawasaki has a lot of getup and go. I had a 500 motorcycle and zero to 60 was hair raising. That's why I prefer 2 strokes
Hello, very interesting video. I have 2 Mikuni 38 carbs on my Kawa jet ski. I changed nozzles and gaskets, cleaned everything.... I put transparent hoses to see the fuel. Problem after filling the hoses with a syringe, the engine runs but the gasoline does not arrive (see the little that remains tends to go back to the tank (no suction to the carbs)? I connected the fuel correctly carburetor according to the plan (intake, return, low engine pump)? I tested the pressure for opening nozzle 19 psi THANKS A LOT
Question about the installation of the flapper valve at the 15:52 mark. Is that flapper valve required on the larger bn 44 carbs used on the 550's? I'm doing a rebuild on that same carb and when I did a rebuild on it several years ago I did not put it in. In the Mikuni rebuild instructions it's indicated for use on the small bn 38 carb. Don't know if I should put it in or not. Anyone know for sure?
Great video. I have the same carb, but how does the fuel get down from the pump to the needle? Is seems that the disk with the pulse inlet is totally sealed (no holes for the fuel to get down to the rest of the carb system).
Yo Brandon could you tell me what exact fuel lines where which that you connected back to the carb. I’m confused on which one is which or tell me what you referenced. Thanks !
Helpful video, thanks! There is so much SBN stuff out there and almost nothing about the regular BN series that came stock in so many JS550s. How long would you say it took you start to finish without the video speed ups? About an hour maybe?
No, yours has the 38. This is the 44 that came stock after 86. You don’t want a BN44, absolute trash and difficult to adjust, put on an SBN and never have carb problems again.
Hahaha, "wasn't that hard just 6 six years of planning and a couple hours of labor." That's good. Regarding the needle adjustments. Did you just start out with all three at 2 turns out?? I did and never really adjusted again but its not perfect. A bit of lag with an idle to full throttle. Please let me know your settings if you ever have a spare moment. Thanks.
Hello brandon ive looked everywhere for the carb tunning and cant find the pilot jet adjustment Would you help me knowing wich manual you use ? And settings for low High And pilot I have a js 440 1988 Ive subscribed and liked your videos thanks a lot
Join the "Kawasaki 550" Facebook group. All manuals are carb info are posted under the Documents section. Also, you could search within that group. Its been discussed a thousand times.
Rebuild kit: $50. Chinese SBN $100. Real SBN $200. SBN rebuild kit $25. It’s not worth it to rebuild those junk BN carbs, replace it with an SBN and never look back.
Brandon, a couple of notes for those following your procedure:
1 - Only use genuine Mikuni parts. Aftermarket Mikuni "compatible" kits are well known in the PWC world to not work correctly and can cause a lean condition that will blow up your engine.
2 - The "Phillips" screws inside the Mikuni carburetors are actually not Phillips but are JIS (Japanese Industrial Standard). Using a standard Phillips screwdriver risks stripping out the heads of the screws. For about $11.00 you can get the Vessel brand JIS driver from Amazon when you order the carb kit and its tip fits the screws much better than a Phillips tip will.
3 - An economical ultrasonic cleaner would be worthwhile for cleaning carburetors. You can use the same cleaning solvent you use now, it just works better with a bit of heat and vibration. A 3 litre ultrasonic is a good size for cleaning these Mikuni carbs. I have heated the same carb cleaner you use up to 40 deg C with no issue and it works much better/faster for cleaning (20-30 minutes as opposed to overnight).
4 - Re-use the original needle spring when rebuilding the carburetor. There four several different spring strengths that Mikuni installed in their carbs and the new one that comes in the kit is probably not the same as the original. As long as it is in good condition, the original will generally work better.
5 - Make sure you test the pop-off pressure of the needle and seat after you re-assemble them. A too high of pop-off pressure can cause a lean condition and too low of a pop-off pressure can make your engine run rich. Neither of these conditions is desirable. You can get a pop-off tester on Amazon or e-bay for not too much money. It is essentially a small hand air pump and pressure gauge that you use to pressurize the supply side of the carburetor. A small squirt of WD-40 on the back side of the needle is used to give a clean pop (back side is where the arm attaches). Careful not to be looking at the needle directly when it pops because it will spray the WD-40 when the spring is overcome. Mikuni pop-off pressures for specific applications are available online.
6- There is a very good Mikuni user manual available on the Mikuni USA site, it has an exploded view and tuning information and instructions on rebuilding these carburetors.
Other than these notes, great video
Other than the video, great notes!
I should have reused the original spring, I told myself I was going to, and you see where that got me.
Also, this was a genuine kit.
Couldn't find a BN manual, only an SBN - probably good enough though.
@@BrandonsGarage I believe the BN and SBN are fairly close. At least close enough to give an idea of how the carbs work and some of the gotchas to look out for.
Hey there, I'd like to pick up one of those JIS screwdrivers for rebuilding my BN34 carb....not really sure what size screwdriver to order though? I assuming the screws in the carb are pretty small....any guidance you can give me on the right size for the screwdriver?
HDMFly the JIS screwdriver I used is the same size as a no.2 Phillips. The one I purchased is the Vessel Megadora 900 +2x100 JIS cross point on Amazon. Hope this helps.
@@DougsMessyGarage Yeah that helps, thanks a lot!
I remember using the standup Kawasaki a lot when I was a teenager. Knee punisher and fatigue maker is what I remember of it, and it would be doubly so now in getting near middle age.
The silver lining memories though were late June or July immediately at legal PWC daylight on the water where it was pure glass smooth water on that machine.
Pretty involved carb. It's a good bad thing when it comes combining the carb and fuel pump. Ran good on the water. Kawasaki has a lot of getup and go. I had a 500 motorcycle and zero to 60 was hair raising. That's why I prefer 2 strokes
Awesome, great editing, I love stand ups
Watched this whole video and realized you’re just down river from me haha thanks for the help
Oh where are you?
FYI, Yamaha used these on early Waverunner 500s and WaveJammers if you want to add that to you description or tags.
Thanks Brandon, I just had the inlet and overflow around the wrong way 🤦♂️Cheers
Hello, very interesting video. I have 2 Mikuni 38 carbs on my Kawa jet ski. I changed nozzles and gaskets, cleaned everything.... I put transparent hoses to see the fuel. Problem after filling the hoses with a syringe, the engine runs but the gasoline does not arrive (see the little that remains tends to go back to the tank (no suction to the carbs)? I connected the fuel correctly carburetor according to the plan (intake, return, low engine pump)? I tested the pressure for opening nozzle 19 psi
THANKS A LOT
nice man
Question about the installation of the flapper valve at the 15:52 mark. Is that flapper valve required on the larger bn 44 carbs used on the 550's? I'm doing a rebuild on that same carb and when I did a rebuild on it several years ago I did not put it in. In the Mikuni rebuild instructions it's indicated for use on the small bn 38 carb. Don't know if I should put it in or not. Anyone know for sure?
Are the base gaskets the same ones used on a Mikuni BN444043 carb? Can’t find anything online about it. TIA
How far from Quartsite are you ? My Dads truck broke down there and he’s 86 so we flew him back home and I need to get it home !
Great video. I have the same carb, but how does the fuel get down from the pump to the needle? Is seems that the disk with the pulse inlet is totally sealed (no holes for the fuel to get down to the rest of the carb system).
Great video. What did you end up doing with that rubber thing in the fuel filter? Did you just put it back in?
Yo Brandon could you tell me what exact fuel lines where which that you connected back to the carb. I’m confused on which one is which or tell me what you referenced. Thanks !
Really good vid. I still have a lot to learn but how did you know you were not running too lean?
Helpful video, thanks! There is so much SBN stuff out there and almost nothing about the regular BN series that came stock in so many JS550s. How long would you say it took you start to finish without the video speed ups? About an hour maybe?
Dude I have a 77 440 and my carb is a little different I need help
is this the stock carb? i have an 83 js550 and it looks the same as this carb but i dont know how to tell what it is. i just bought the ski.
No, yours has the 38. This is the 44 that came stock after 86. You don’t want a BN44, absolute trash and difficult to adjust, put on an SBN and never have carb problems again.
Hahaha, "wasn't that hard just 6 six years of planning and a couple hours of labor." That's good.
Regarding the needle adjustments. Did you just start out with all three at 2 turns out?? I did and never really adjusted again but its not perfect. A bit of lag with an idle to full throttle. Please let me know your settings if you ever have a spare moment. Thanks.
Depends on your ski but most default settings were 1 turn out
@RyanMcIntyre thanks
Hello brandon ive looked everywhere for the carb tunning and cant find the pilot jet adjustment
Would you help me knowing wich manual you use ?
And settings for
low
High
And pilot
I have a js 440 1988
Ive subscribed and liked your videos thanks a lot
Join the "Kawasaki 550" Facebook group.
All manuals are carb info are posted under the Documents section.
Also, you could search within that group. Its been discussed a thousand times.
@@BrandonsGarage okay thank even if i have a 440?
@@jimmy2fois263start at one turn out each screw. Your carb is different but super simple
Dang makuni carbs are a pain ! And Tillotson can be just as bad !
Rebuild kit: $50. Chinese SBN $100. Real SBN $200. SBN rebuild kit $25. It’s not worth it to rebuild those junk BN carbs, replace it with an SBN and never look back.
You need to stop fast forward ok