83 GS650L - Pilot Screw, Pilot Jets, and Pilot Air Jets

[Guest]

Following the Mikuni BS32SS (CV) Carburetor Rebuild Tutorial,

I have purchased the o-ring kit from Mr. Barr, and have all new SS bolts to replace the tired phillips screws.

- Working on getting everything disassembled, and have run into the common issues with stripped screws.
-- The first is what he calls the "Pilot Screw" (I'm assuming he means the idle mixture screw), on the outside of the carb (engine-side). I got 3 of them out but one is completely mangled and will have to be eased out using heat/pb/hammering a screw driver into it most likely.
:: Even though I got most of them out, several are pretty rusty, especially the springs. Would it be a good idea to just swap them out? Where's the best/cheapest place to get them? I've seen several people suggest these, http://www.mikesxs.net/parts/yamaha-...m-12r-14105-00
But it says these are for the BS34 carbss, are they the same as the BS32SS carbs?


Now here's where all the names/terminology get confusing.
- Moving into the float bowl, Upon disassembly, I've found that I am missing all 4 of the rubber pilot jet plugs that cover the pilot jets. I'm assuming they are important and should definitely be replaced, so where's the best place to grab those?
- Also, I am currently soaking the pilot jets and I'm going to heat them up before trying to unscrew them as they seem very soft and easy to strip. Any advice on these? Also, a few of them are already stripped, so would these be my best bet?

http://www.bikebandit.com/aftermarket-parts/motorcycle-fuel-and-air/carb-kits-parts-accessories-universal/mikuni-pilot-jet-kbs30-96-4-pack?b=58169

The GS650L calls for the 42.5 Pilot Jet, with the crossdrilled holes, correct?


Last but not least -- the Pilot AIR Jets
I haven't tried pulling these out yet, but I'm assuming they will be just a tough to get out and at least one is already stripped from the PO that obviously didn't know what they were doing.
-- Best place to grab a few of these for back ups?

Thanks for any input and advice!

- German

[GermanGS]

I've done an extensive and exhaustive amount of research on all of these parts, without any clear and concise answers to my questions. Any help is appreciated!

Thanks!
- German

[tom203]

The rubber plugs over the pilot jet are commonly available- some one will chime in on where.. As to the stubborn pilot jets, make sure you modify a screwdriver to fit them perfectly - the tip must fit across the jet slot completely: this means that you have to grind back the driver shank so it can reach down the tunnel.i

As to mixture screw, you can cut down the column to reach it better or get a decent left hand drill to carefully grab it. Avoid easy outs ,screw extractor gizmos.

Those mikesxs mixture screws might maybe the same as for the bs32- I'm not sure, but someone should know

[GermanGS]

Thanks Tom,

I've been having a little trouble getting flat head screw drivers that are thick enough to fully fit in the slots, so I'll have to come up with something for that.




Any other info on these issues would be really appreciated!

- German

[geol]

Leave the pilot air jets alone. These are located on the venturi edge and basically would be hard to clog and you can run a wire through them if in doubt. The holes are just a tad under 2mm. The pilot jet plugs are really very necessary. These rubber plug plug the pilot well because the pilot jets draw gas from the main jet well via a small hole crossing between the two wells. The pilot jets are Mikuni type BS30/96 and you can strip the head fairly easily. Get a small screwdriver and file the sides to it will fit into the well and you may have to file flat the tip a bit to make it wide enough to engage most of the slot on the head. While heat is sometimes needed to remove these, don't use a MAP gas torch; only a propane. Also, they usually will come out without heat if you put the screwdriver in the slot and tap it with a hammer... poor man's impact driver. You might also put some penetrating oil down the well the day before you attempt removal. If stripped, keep in mind the slot is miserably shallow and you can just tap a #1 EZ into the existing hole and turn the screw out in most cases. Last thing and something not mentioned are the float posts. The float pin that sits the holes in the posts is typically very very tight and easily broken if you try punching it out while the carbs are together. You can take them apart and make a little support and lay your carb body on it so the bottom post is supported. Perhaps make a hole in the support to receive the pin. Use a larger punch to move the pin down flush with the post which doesn't have the pin end with the head and then use a correctly sized smaller punch, tapping gently, to move it through. Vice grips are seldom need and if you use them, keep in mind you will likely deform the pin or bend it.

[Chancho196]

I had the same issue with the mixture screws on the 550. I used the advice from here and they came out a treat. Here's the pics etc. http://biketech7.blogspot.com.au/201...or-seized.html

[Nessism]

I think I've got a few spare pilot screws (Suzuki's/Mikuni's terminology) & springs. PM me if you want me to look. I'm pretty sure the pilot screws are the same for the different size carbs.

[GermanGS]

Leave the pilot air jets alone. These are located on the venturi edge and basically would be hard to clog and you can run a wire through them if in doubt. The holes are just a tad under 2mm.

So these do not need to be removed before dipping them? On the rebuild sheet it doesn't look like they have o-rings or gaskets of any kind, but I wanted to make sure before dipping them. Thanks for the heads up!

[geol]

They don't have to be removed; they can be hard to get out and can strip. These are not critical to remove.