Hand-turnable idle mixture screws/rear brake light switch

[mr_misfit138]

Hey everybody,

I was just wondering if anybody knew of anyone that sells longer idle mixture screws for our bikes, that extend out past the top of the carbs, so they can be turned by hand. I know they're not really necessary, as ours are easy enough to access with a long flat head and the tank on backwards, but I'd like to make the change anyway, if I can find them.

Also, with the SG I have, and the 2 SH's my dad and brother have, none of our bikes have rear brake light switches. And since they're not on the OEM diagrams I've seen, I'm guessing that they came without them from the factory. I'd like to add one to my SG, but I'm not sure where to find one. Mike's XS has one for 650s, but I don't know if it's compatible with XS11's. Has anybody added one to their bikes? If anyone's got a part number that works, that would be awesome.

Thanks for your input.

[IanDMacDonald]

Why make changes that are not necessary? How many times do you adjust your carbs to justify the need?

Umm, am I crazy, or am I the only one with a rear brake light switch on all of my XS bikes? I cannot attest to your XS missing a switch, but, can state with confidence that all five of my Yammies have brake light switches.

If your's is missing, check out ebay: http://www.ebay.com/sch/i.html?_trks...at=0&_from=R40

[DGXSER]

All of the XS11s came with a rear brake light switch from the factory. It is in different places on different schematics. For both the SH and the SG, it is part 37 of the Electrical 2 schematic.

The part number is 1J7-82530-02. Google it and several sources will come up.

[CaptonZap]

On the 80G, http://farm5.static.flickr.com/4054/...1ae5cbd4_o.gif
it shows as a green with yellow wire from the brake light to the front and rear switches. Power is fed from the brown wire to the switches.
The rear switch is located on a bracket welded to the frame member just in front of the rear master cylinder. A wire with a spring goes down and hooks
to an arm on the brake pedal assembly.
There are a number of "Universal" switches that can be adapted for use.
CZ

[mr_misfit138]

Why make changes that are not necessary? How many times do you adjust your carbs to justify the need?

The bike runs pretty strong, but it doesn't run "right". I've been adjusting the carbs nearly nonstop to get it then dialed in correctly, and so far it hasn't worked. I cleaned up and tuned my dad's SH that sat with gas in the carbs for years, and it's running perfectly now, but mine and my brother's are not playing nice. When I put the Colortune on them, they don't show either blue or orange, just kind of a muddled mix, and it doesn't change no matter how the idle mixture screw is adjusted. I'm figuring I've got leaks, so I'm replacing every gasket and seal I can on the top end, and I figured that I should probably replace the mixture screws and o-rings themselves, and I just think that it'd be nice if they were a little easier to get to, but more importantly, easier to see. The only problem is that I've never seen them for our carbs. It's not a big deal, but just a preference, I guess.

All of the XS11s came with a rear brake light switch from the factory. It is in different places on different schematics. For both the SH and the SG, it is part 37 of the Electrical 2 schematic.

The part number is 1J7-82530-02. Google it and several sources will come up.

Thanks for this info DGSXER. That is listed in a kinda weird spot, but I found one and have it on order now. Thanks a bunch!

[motoman]

The bike runs pretty strong, but it doesn't run "right". I've been adjusting the carbs nearly nonstop to get it then dialed in correctly, and so far it hasn't worked. I cleaned up and tuned my dad's SH that sat with gas in the carbs for years, and it's running perfectly now, but mine and my brother's are not playing nice. When I put the Colortune on them, they don't show either blue or orange, just kind of a muddled mix, and it doesn't change no matter how the idle mixture screw is adjusted. I'm figuring I've got leaks, so I'm replacing every gasket and seal I can on the top end, and I figured that I should probably replace the mixture screws and o-rings themselves, and I just think that it'd be nice if they were a little easier to get to, but more importantly, easier to see. The only problem is that I've never seen them for our carbs. It's not a big deal, but just a preference, I guess.



Thanks for this info DGSXER. That is listed in a kinda weird spot, but I found one and have it on order now. Thanks a bunch!

Idle mix ports likely pulling air by the teny O-rings on the idle- mix screws. If they've never been out, they may look like hard fiber teny washers. There should be a teeny washer up against the spring first, then the O-ring.

[mr_misfit138]

Idle mix ports likely pulling air by the teny O-rings on the idle- mix screws. If they've never been out, they may look like hard fiber teny washers. There should be a teeny washer up against the spring first, then the O-ring.

I've pulled them out before and all the washers, o-rings, and springs looked good, and the tips of the screws looked good too, but I'm wondering if the o-rings looking good didn't necessarily equal the o-rings being good. I'm already about $400 into new parts on order for resealing everything, so might as well add a few more bucks for new o-rings and mixture screws...

[bikerphil]

Have you tried resealing the intake boots to the head with RTV? Old leaky gaskets will cause tuning nightmares. JAT

[mr_misfit138]

Have you tried resealing the intake boots to the head with RTV? Old leaky gaskets will cause tuning nightmares. JAT

Even better. I spent $100+ on brand new intake boots 2 years ago. It still didn't fix the issue though. I put new plugs in, I double and triple checked the jet sizes and float heights, made sure all the jets are perfectly clean, replaced the float needles, seats, and o-rings with brand new ones, replaced the air filter, made sure that there were no blockages in any of the fuel or air passages, ran new vacuum lines, fuel lines, added in-line fuel filters, rebuilt the petcocks synced and re-synced carbs, and the mixture screws still won't do a damn thing to register anything on the Colortune. Pretty much everything is new from the air box and fuel tank to the carbs, except the pilot screw o-rings. So, hopefully replacing those, and all of the gaskets and seals, will kill any leak there is anywhere, intake or exhaust. And if I end up replacing any parts that are still in good shape, I have 2 other runners and a parts bike that could probably make good use of them.

[natemoen]

When you replaced the boots I hope you tossed the POS paper gasket that came with them and used some RTV instead.

Also, sometimes the brass sync tube on the boots leaks some. I had a tube come completely out on one boot.

[bikerphil]

Is it on all 4 carbs there is no response from the mixture screws? If it is just 1 or 2 you probably still have a blocked passage in the low circuit. There are 3 or 4 outlets in that circuit on each carb so blowing compressed air thru them with your finger(s) covering the other holes is really the only way to know if they are absolutely unobstructed.

[SFerinTEXAS]

Is it on all 4 carbs there is no response from the mixture screws? If it is just 1 or 2 you probably still have a blocked passage in the low circuit. There are 3 or 4 outlets in that circuit on each carb so blowing compressed air thru them with your finger(s) covering the other holes is really the only way to know if they are absolutely unobstructed.

I agree with this. If you want to test the mix screw for leaking , fill the area above the screw with atf or some other combustible liquid and see if it drops done the screw tower.

[mr_misfit138]

When you replaced the boots I hope you tossed the POS paper gasket that came with them and used some RTV instead.

Also, sometimes the brass sync tube on the boots leaks some. I had a tube come completely out on one boot.

This is something I did not do... Thanks for bringing this point up. I never even would've thought about that. I'll make sure to pull them off and RTV them to the head when I disassemble everything. I'll re-seal around the sync tubes too.

Is it on all 4 carbs there is no response from the mixture screws? If it is just 1 or 2 you probably still have a blocked passage in the low circuit. There are 3 or 4 outlets in that circuit on each carb so blowing compressed air thru them with your finger(s) covering the other holes is really the only way to know if they are absolutely unobstructed.

Yeah, all 4 are about the same. I blew a bunch of air through everywhere I could stick the nozzle and felt it as it came out, and everything seemed to be equally unobstructed. The hard part is that the bike does actually idle differently when I mess with the idle screws, but the Colortune doesn't change at all. At first I thought it was just that the Colortune was defective, because I tried it on mine and my brother's bike first, with the same results, but when I tuned up my dad's bike, it worked perfectly, and the blues and oranges were clear as day. I've somewhat tried to dial it in just by reading the spark plugs, but I don't have the patience for making an adjustment, driving around, pulling all the plugs, making more adjustments, driving around again, pulling the plugs again, etc., etc., etc... Especially since I've done it the Colortune way, and it was a breeze.

[IanDMacDonald]

Interesting. Just a weird thought, but, is it possible that your air/fuel screws are stripped, and they are actually not turning?

[mr_misfit138]

Interesting. Just a weird thought, but, is it possible that your air/fuel screws are stripped, and they are actually not turning?

I don't think so. They move in when I screw them down all the way until they seat, and they unscrew all the way until they come out. They're definitely threaded, and they're definitely affecting the idle when they're messed with, but they're just not letting a distinguishable color show through while Colortuning. I haven't ever heard of anyone else with this issue. It was just a few people's best guess that I was intake/exhaust leaks that would cause this. And before I changed the intake boots, I definitely had a leak. Replacing them made the engine stop revving up when starting fluid was sprayed around the carbs, but it didn't straighten the Colortune out. And, if anything, I would've figured that an intake leak would just equal a lean condition, which would be register as solid blue, but obviously either that logic is wrong or the problem lies elsewhere.