Pilot Jet SCREW Identification

[MalA]

Hi All

I have recently acquired an XS11RH. This is an '81 model made for the Oceania region. I live in Western Australia.

The Previous Owner, attempting to do a tune, managed to jam 3 of the 4 pilot jet needles into the carby bodies, snapping them off in the process.

Now, before you all scream at me to do a search and read all the excellent stuff on this forum regarding this matter, I plead that I have done so. I think I now have a fairly good idea of what I need to do.

However, I have a problem in sourcing the replacement needles. Two different sets of needles have been supplied by Yamaha Australia, both wrong. I have browsed online fiche of different models until my eyes have crossed Trouble is that there is not enough definition in the fiche images to tell the difference in shape).

I have also browsed the catalogs of several aftermarket parts suppliers in the US, but again, there is not enough definition in the images to be sure.

I have attached an image of the sole needle still in one piece. I should add at this point that Im not even sure if the carbs are the originals, or if they have been swapped.

Can anyone identify it and possibly tell me where I can source replacements?

Hope someone can help.

Thanks
Mal

[IMG][/IMG]

[mro]

Is that a plastic cap on top?
Does not seem to be from BS34 III carbs.
How about a pic of the carbs themselves?

mro

[randy]

That sure looks like an early type '78-'79 tapered type screw that's been jammed a few times, but that doesn't match the '81 year. Sure you got '81 carbs? any more pic of carb so we can figure out what you have?

[CatatonicBug]

Remember guys, this is an RH. The Aussie version is a piecemeal of several other models, with some parts unique to this model alone. The handlebars are one obvious piece that do not swap to any other model.

However, according to the benefiscal site, the pilot screw should look like this from the top:



The parts fische DOES show that the screw has a larger head on it, but maybe that's just artistic license?

[randy]

The screw in the photo is an early type with a limiter cap glued on. The dealerships commonly installed the limiters as part of a tune-up when the emission standards called for it. The cap prevents adjusting the mixture too far rich/lean.

[TopCatGr58]

Hey Mal,

That pilot SCREW is from the 78-79 series carbs, the screw head is large and sits on the outside/top of the carbs, not down in a tunnel. As mentioned, the plastic cap is just a tuning adjustment limiter,not really needed.

Regrettably, it's difficult to find just the screw. BikeBandit carries them separately, for $20.00 USD a piece!!! You can get a whole carb kit for that price. A few places like Z1enterprises.com or carbkitcapital.com sell complete kits with that specific screw in them, again for the 78-79 models!!



I just looked on Ebay, and there are some 4 sets of kits for a decent price, but you're also getting jets and needles, float valves, needle seats, etc., possibly a lot of parts you don't need, but then again, it's nice to have spares, and since the kits are cheaper than the price of just the screw alone, why not!?
T.C.

PS, Bug, you're probably right for an OEM setup, but no telling for sure if he's got stock carbs, etc., and from the looks of that screw, it's definitely not the type that fits down in the tunnel designed carb bodies!!

Also, Mal, a newer trick for removing the broken tips is to put the carbs in the FREEZER, seems to shrink the brass tip more than the body, or just helps to stiffen the metal so that you can push/poke/prod on the little tip a bit better, easier, and they seem to pop out easier, using the other techniques mentioned in the tech tips!

Also, some folks have put their old scews on a drill/lathe and have turned the broken tips down to make a new point using a file, emory cloth, etc.! Might be easier and cheaper than buying a bunch of new parts!?!?

[MalA]

Thanks for the responses guys.

Marshall - Im definitely getting the impression that this model is made up of all the spare bits Yamaha found on the factory floor after they did a sweep up
The image you showed has the needle in a recess which is not the case with mine. It sits quite obviously on the top of the housing as Randy points out.

T.C. - Thanks for that image from Z1. I had already seen it but I was unsure if it was the right one as the needle I have has that little step in it. I should have guessed that shape was just the result of a bit of heavy handed butchery
Now that I know its not a unique shape, I will go ahead and order them. Mind you, I think your idea of turning the old ones down is inspired. There is about 6mm of thread that stands proud of the housing. I know some of that is required by the spring, but I had already considered doing away with that as it seems to reduce the sensitivity as you screw the jet in. I thought of putting a dab of araldite on the jet once it was tuned to stop it moving. So, there is quite a bit of thread you could turn down to reshape the needle. Its a good fallback idea!

Once again, thanks for the help one and all

Mal

[GARTHXS]

keep the springs

they give excellent feed back, and good luck trying to retaper the old screws,DAHIK just pony up the cash and get new or even cheaper used in good condition, and be thankful if you havent broken off the tips of any of these little buggers, I am just finished getting one out of my 79f carbs what a PITA