(BS series) Throttle Seals: Who's done 'em, who needs to?

On staking the screws in, seems like a single shot at the thread line with an automatic center punch should be sufficient. That's how I have done them in the past, on Yammie triples, anyway.
 
Is anyone willing to sell me some shaft seals and screws? I PM'd Sandy but then realized he has not logged in for ~3+ months. I have BS38 carbs.
 
I recommend using the genuine Yamaha seals now. They cost little if any more than the MikesXS offerings and you can be assured of the quality. The quality of the MikesXS seals is hit and miss, I guess depending on which Chinese factory that particular shipment came from, lol.
 
As luck would have it, I've got one pair of each, a pair from MikesXS and a pair from Yamaha.

Would make for a literal side-by-side comparison. :wink2:

5twins,

Not sure about your Yamaha Seal inventory, but I assume you have the screws, (I bought same ones as you recommended) and you are also in the Empire State, so you could get them to machstang much more quickly than I can. I'll be glad to send him some from TN. Matters not to me. :)
 
No matter to me either, he can P.M. either one of us. If you're going to use those Mikes seals, I recommend putting them on the left side of each carb. That way they can be replaced without removing the butterfly plate again if they go bad.
 
Haven't replaced mine yet. Have a set of BS38's from a 77XS650D. Doing a jet change to compensate for open intake and exhaust. Sounds like a bit of a hassle. Most of the hassle seems to be alignment of throttle plate to carb body. Where are the OEM parts for this 36 year old machine to be had. Thanks Dirty
 
Haven't replaced mine yet. Have a set of BS38's from a 77XS650D. Doing a jet change to compensate for open intake and exhaust. Sounds like a bit of a hassle. Most of the hassle seems to be alignment of throttle plate to carb body. Where are the OEM parts for this 36 year old machine to be had. Thanks Dirty

Knoxville?!? I went to UTK many years ago....

I get Mikuni Jets from: http://650central.com (go to Carburetion OEM).

Partzilla also has some OEM parts for BS38's (Throttle Shaft seals, floats, etc.)

http://www.partzilla.com/parts/search/Yamaha/Motorcycle/parts.html

You likely have to go to MikesXS for some carb parts. NON-OEM.

Also, check eBay for hard to find new old stock carb parts for 650's, but you'll pay dearly for them...
 
Jets-R-Us has genuine Mikuni jets plus some other tidbits for the XS650.

548502_398565370173466_509661555_n.jpg
 
Honestly, you should run it at the 1200 spec hot. Yes, they will idle lower but can just up and stall from time to time for no apparent reason if you set the idle so low. It did seem rather high when I first got my 650 but I'm used to it now. My other twins idle lower and that is what threw me. I initially set it lower until I encountered that random stalling problem.
 
Thanks guys for helping out! I got Yamaha seals from boats.net. Got my idle down to ~1000 rpm.

Cool, machstang. I've ordered alot from boats.net.

Boats.net is the Marine Site for Partzilla.com. Partzilla, Boats.net and Powersports Plus LLC are all part of the Outdoor Network Corporation. I don't know all of the business structure, but they are all part of the same company.
 
Hey machstang, i pmed you a while back but it seems you figured it out anyways, congrats. I do have a bunch of the McMaster seals and screws left if anyone needs them.
 
They worked great. Just remember to install them correctly. You want the "flange" part facing out. The idea being that the vacuum created by the carbs intake will suck them against the carb housing, thus sealing the shaft.
Just to confirm, by "flange part" you're referring to the slightly wider edge when viewing from the side, and it goes away from the carb body?
 
Have just read this thread and want to say thanks to all who have contributed, as always this has/will save me a ton of aggravation. I will be reading it at least one more time. I am in the middle of rebuilding a pair of BS38's which are on my '83 HS. Presumably the PO installed them? I believe they are the BS 38 584/2F0 versions based on gggGary's picture and some other reading. The only comment I have is regarding using WD40 with rubber, don't know about Viton or other special materials but some years ago someone told me WD40 eats rubber. To prove it he inflated a balloon and then sprayed it with WD40. It immediately burst. Then he sprayed a second balloon with an industrial lubricant which was supposed to be safe for rubber. The balloon remained inflated. Maybe this was some kind of chemical voodoo but just hoping this may save some premature deterioration and related work.
Yamimoto
 
In trying to help whoever reads this down the road, could someone please correct my mistake?

I not only stripped one butterfly screw, I managed to strip three, with my JIS bits no less. I had the carbs firmly pressed down at waist level, thought I had my best JIS tip in the screw, and applied firm pressure down before starting to try and slowly turn. I got each screw to make a sleight crack, but only one truly broke free before stripping. In hindsight I should have let them soak in some penetrating oil beforehand but I guess I was a little overconfident in my JIS bits as this is the first time they've failed me (yet to strip anything else between electrical work, points work, and touching just about every other screw on the bike).

Did I miss a crucial prep step that everyone else took, or are some screws just destined to strip?
 
These are very touchy hopefully just the head is stripped not the threads? I've done a few carb sets and so far think I only stripped one screw head a ways back. Secrets? well like you say rust buster, if they won't loosen, try to tighten a little. a LIGHT tap with a hand impact is not out of order here. Support the back of the shaft, maybe a 1/4" socket extension clamped in a vice? Don't want to bend a throttle shaft but that will break loose the crud. Heat like from a hair dryer or VERY careful use of a heat gun. I think a heat gun could turn a carb into a metal puddle. The screw is steel, the throttle shafts are chrome plated brass, rather soft.
 
Yeah, thankfully just the heads. Looks like heat and a drill are the way to go. I'm getting some help from a friend who works in a shop full time so we have proper resources as my supplies are still limited. Guess it could have been bad technique on my part.
 
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