Mikuni jet details - 81 gs650g - bs32ss

[WilliamGLX81]

Hey, folks. Long time no post (or ride).

I'm cleaning the carbs on my 81 gs650gL, and ran into a few things I could use a hand with. These are on Mikuni BS32SS carbs.

I removed one Needle Jet (the jet part that the needle slides into), and discovered that either I or someone else lost a thick brass washer that goes between the Main fuel Jet and the Needle Jet. The washer is shown on the diagram, but not numbered.

It measures 5.3mm ID, 10mm OD, and 1.5mm thick. The replacements I have found in 20 minutes on the internet (half the links for metric washers lead to ASE washers) are all 1.0mm thick. I'm concerned this could cause a problem by shifting the main jet inlet higher in the fuel bowl. If not, I can replace all 4 with the slightly thinner washers.

Second, someone seems to have put in somewhat different pilot air jets - instead of 160x4, it has 175, 155, 150, 150. All other jets appear to be correct (mains are all 110, pilot fuel jets are all 42.5).

I'm of the mindset that I would rather replace all of these jets at this point since they're filthy/corroded, and I've never replaced them. Looking at a company NicheCycle, I could get a kit of all 3 of the jets (4 each) that I can physically locate in the carbs for about 50 bucks. I can't figure out where the "main air jet" is. I see a spot on the right hand side (from the airbox), but there doesn't appear to be anything inside of it.

Thanks in advance for any help!

 

[Kiwi Canuck]

Washers for the main jets are available from Suzuki, part # 39.

https://www.partsoutlaw.com/oemparts/a/suz/50d3fda6f8700230d8b4dab4/carburetor-model-x

 

[steve murdoch]

Have a look at this tutorial.
It should show you where the mains are.
http://zeus.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

 

[WilliamGLX81]

Have a look at this tutorial.
It should show you where the mains are.
http://zeus.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

I've been through that before, and it's a good guide. But it doesn't say a word about "main air jets". They're on the right hand side of the inlet side of the carb, opposite of the pilot air jet.

 

[Steve]

Your pilot air jets should all be the same. The manual does call for 160s.

Your "main air jets" are, indeed, in the hole at the 4 o'clock position on the intake. They are NOT removable.

Yes, there is a 'proper' brass washer for the main jet. If you can't find any, let me know, I have some spares.
In the mean time, the difference in thickness does not matter.

.

 

[WilliamGLX81]

Your pilot air jets should all be the same. The manual does call for 160s.

Your "main air jets" are, indeed, in the hole at the 4 o'clock position on the intake. They are NOT removable.

Yes, there is a 'proper' brass washer for the main jet. If you can't find any, let me know, I have some spares.
In the mean time, the difference in thickness does not matter.

.

Ah, thank you! Just the confirmation I needed. If the height isn't critical, I'm sure I can find one. Maybe the local Ace hardware has some. I have copper washers, but I think galvanic corrosion could be a problem if I add copper to the brass and aluminum mix.

Thanks everybody for the replies.

I was able to find the brass washers listed on nichecycle along with the jets. The prices are really good. I found someone's Excel spreadsheet in french, but it cross-references Suzuki PN 13332-44080 to Mikuni PN VM20/169 and lists dimensions that match - 5.4x10x1.5