Rubber caps

[RobMan]

Hey Guys,
I've searched through everything and unless there is an old, old archive somewhere I haven't found an answer to this situation. When I first removed my carbs and pulled the float bowls there were black rubber caps inserted in the tubes housing the main jets. It looked as though they were held in place by both mild friction and the pillar(?) extended up from the bottom of the bowl itself. What gives? Do I need these in or not? I hop not as I think I've mislaid them whilst working on all the individual systems.

[Snow]

Is this a US XS11 or an XJ? I've never heard anything about main jet caps, but I am still learning - though I've had 3 or 4 sets of XS carbs opened up and never saw the likes of black rubber caps.

In my GS750 carbs, there were some black caps.

Come to think of it, I think that I remember reading somewhere in the forums about Yamaha shops being happy to sell you caps b/c their microfiche was wrong or something like that.

[Ken Talbot]

IIRC, the black rubber caps are over the pilot jets on later carbs, not the mains. The earlier carbs were blocked in this same location with a brass screw. They were there for a reason and I'm pretty sure they will need to be replaced. The good news is you could carve some new ones from a rubber stopper if you can't get them from Yamaha.

[skids]

I have two sets of later carbs. A set from an 80SH and a set from an 81H. Neither of those sets had rubber caps in the float chambers. In fact, I wouldn't know how the pilot jets would get fuel if the openings were plugged-off. I wonder if Yamaha had to use-up some of the 79 vintage carbs and decided to use rubber caps instead of screw-in plugs? If they are indeed plugged, there should be a passage between the main jet and pilot jet areas to supply fuel to the pilots and the main jets would be more like 137.5's instead of 110's to 120's, I would think. Can anyone verify this?

Originally posted by Ken Talbot
IIRC, the black rubber caps are over the pilot jets on later carbs, not the mains. The earlier carbs were blocked in this same location with a brass screw. They were there for a reason and I'm pretty sure they will need to be replaced. The good news is you could carve some new ones from a rubber stopper if you can't get them from Yamaha.

[nashville_bill]

You can buy the "Rubber Passage Plugs" part # 48-5002 from Mikes XS. Look around the website and you will find lots of parts for your XS11.

http://www.650motorcycles.com/mikesxs.html

Telephone (352)540-9204

[RobMan]

O.K., O.K. I just read Blaines FAQ on carbs from 2002, (before my time) and in it he's saying that the 80SG has no capped pilot (not main-my fubar) jets. But, he also says that there is no T between the 1-2 & 3-4 bodies (mine does) and has only 2 hoses coming from the petcocks, (mine has 4).
So, it could be that PO put in diff year carbs? Or diff model?
I still haven't gotten past my electrical probs to even see if she'll start and stay running, just trying to make sure I've covered everything.
BTW, what significance of the steel balls with springs behind them on 1 & 4 for choke rod. Neither one has this, will it be a prob?
Thanks to all

[pgg]

You can stiffen the choke lever with a brass washer behind the circlip.

[Ken Talbot]

The steel balls are detent balls that will hold the choke lever in either of the two 'on' positions. They catch on a small indentation on the choke rod. Without the balls, the spring in the choke assembly will pull the lever back to off as soon as you remove your hand.

[RobMan]

Thanks pgg and Ken. I figured I'd have to have the balls (to ride an XS?)-sorry about that
But, I'm still unclear 'bout the caps and whether I even have the right carbs on my bike. I've been playing with the electrics so long now, I really don't know what I've got.
All I know is this....
Yeah, that's about it. No, I've narrowed it down to either a faulty emergency cutoff (which I'll meter Weds.) or a wire in the headlamp...no horn after a weak and dying beeeeeeep.
All this after replacing coils and pickups, but, still having to jump the solonoid to get a crank out of her. Any ideas, gents?

[pgg]

Chances are you'e got some dodgy wiring contacts. The old plastic connecters are dicy at the best of times.

[Bill]

RobMan wrote:

All this after replacing coils and pickups, but, still having to jump the solonoid to get a crank out of her.

One of the easier contacts to check and clean in the starting circuit is the starter button. It looks like this:



The button, the copper spring and the base contact can get coroded with time. The buttons can get brittle and crack. And, of course, any spring-loaded part is easy to lose! The picture above is from Parts 'n' More where they list a replacement for $6.00. I think Mike's XS 650 may also have them.

To begin with, you could check the function by shorting across the contacts. Good luck and keep us posted!