Fuel screw trouble

[cajun31]

Thanks for the safety tip, I did freshen up the calipers but I am having trouble successfully bleeding the front system. Tried the speed bleeders with a Mitey Vac, didn’t work. So then put the original bleeders back on to pump fluid (with a big syringe) from the bottom up, didn’t work. It’s the last repair before I can ride it so I need to come up with a working strategy

No where in any of your posts have you said what brake lines you are using. New or old? The reason I ask is because of the comments about bleeding with the MityVac. I had the same problem and I still have the original lines on my current project. I will second about checking the spooge hole. To clean it I use a bread tie wire. What I found with my bike was the original brake lines were blocked with crud. To clean them I got my hands on an old guitar string and some brake cleaner. Run the string down the line... remove shoot brake cleaner in and repeat process until you can shoot brake cleaner straight through the line. Once the lines and the spooge are clear you can readily pull fluid through with the MityVac.

[Bonz]

cnap504 Did you rebuild the master cylinder? When squeezing the brake can you see fluid or bubbles from the spooge hole in the reservoir base? If that spooge hole is blocked it'll give you all kinds of issues when trying to bleed.

---Bax

Yes, the spooge hole... always seems to crop up with respect to the XS.

[Bax]

cnap504 Did you rebuild the master cylinder? When squeezing the brake can you see fluid or bubbles from the spooge hole in the reservoir base? If that spooge hole is blocked it'll give you all kinds of issues when trying to bleed.

---Bax

[cnap504]

Thanks for the safety tip, I did freshen up the calipers but I am having trouble successfully bleeding the front system. Tried the speed bleeders with a Mitey Vac, didn’t work. So then put the original bleeders back on to pump fluid (with a big syringe) from the bottom up, didn’t work. It’s the last repair before I can ride it so I need to come up with a working strategy

[cajun31]

Watch for sticking brake calipers!!!! If you did not pull them apart, I WOULD do so BEFORE the first ride. The caliper is aluminum and will stop the piston from returning after one or two times. If you have gone through them, then bleed and enjoy the ride!

I strongly second what Ray is advising. Often overlooked but crucial to a safe ride. Don't skimp on redoing the brakes. If you have already done so then cheers ... bleed them and ride. If not then look up a company such as brake crafters and get them rebuilt properly. Stainless pistons now will keep you from ever having to worry about them again. Another suggestion ... if you don't already own one is to get your hands on either a MityVac or something similar. It makes bleeding the brakes quicker, cleaner and much less frustration. They are also in my opinion crucial in doing a full brake fluid replacement no less then every two years. I have learned that one the hard headed way. Get into the regimen of doing that and you never have the problems that many face with locked up rusted sticking calipers.

[DiverRay]

Watch for sticking brake calipers!!!! If you did not pull them apart, I WOULD do so BEFORE the first ride. The caliper is aluminum and will stop the piston from returning after one or two times. If you have gone through them, then bleed and enjoy the ride!

[cnap504]

I got the carbs back together and installed them and it now has been started and run for the first time in almost fifteen years. I did all the necessary maintenance and repair a 15 year non running bike would need, and as soon as I finish the brake fluid bleeding this bike will be ready for a test ride.
Excited to ride a 41 year old classic

[cnap504]

Thanks everyone for the recommendations. I found a Yamaha oem idle fuel screw part number 11J-14105-00-00 it’s the one I needed for the Mikuni BST 34 type III carbs on my 1980 XS1100 Special. There are aftermarket fuel screws available as well. Thanks again

[cajun31]

These will fit too. 4X For Yamaha XV250 FZR750 XV750 XV1100 FJ1200 Fuel Air Mixture Screw Set | eBay

[FJ111200]

The screw is damaged beyond repair

Still curious what the oem part # is
12R-14105-00-00
11J-14105-00-00
or none of the above, I’d rather buy original equipment than aftermarket when I can.

I used the 12R1410500 from the FJ1200 in a set of XJ1100 Mikuni 34mm i was repairing. Same things for the XS1100 81 LH Midnight Special. PILOT SCREW SET for FJ1200 1986 1TX ENGLAND 261TX-310E2 - order at CMSNL

[cajun31]

go on Ebay and do a search for 1980 idle mixture screw and you can find full sets of four of them for a very reasonable price.

[DiverRay]

OEM part number will change over time. You would need to start with an '81 parts fitch, and go up about every five to ten years to follow it. You could also go to your local Yamaha dealer and have them look it up. As you know the carb model, BS-34 Type 3, they can find it. The one from Mikes works well, and as that is NOT a jet or needle main valve, there are no problems with the part. Also, it comes with the small parts that MUST be changed at the same time to keep the carb working correctly. The dealer will want about 5 times the price for all the parts, and may take a month or two getting them.

[cnap504]

The screw is damaged beyond repair

Still curious what the oem part # is
12R-14105-00-00
11J-14105-00-00
or none of the above, I’d rather buy original equipment than aftermarket when I can.

[bikerphil]

The one in the link is the correct one, for the BS-34 type 3. Is the screw stripped or the carb body?

[cnap504]