Mikesxs BS38 Pilot Mix Screw O-Rings

79josh81

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So I just got some new pilot screws for my 79’ with BS38 carbs. Mikesxs has a disclaimer about the o-rings on the replacement mix screws not fitting in all carbs potentially. Of course I’m one of the sorry sons of a bitch that the o-rings ended up being to big for my carb body. I would just pull the o-rings off of the old mix screws but one of them is broken through. So now what? What o-rings have you guys used?
 
If someone can reply that knows much more about these carbs than I do, would the carbs on a 1978 take the same orings as this 1979?

If so I have a few of them siting right here on my desk. They could be in the mail to Wisconsin in the AM, heck even if no-one knows I'd send some just to try if 79josh81 could start a conversation with me with a mailing address.

Spec's on these are 1.3X2.5 mm
 
If someone can reply that knows much more about these carbs than I do, would the carbs on a 1978 take the same orings as this 1979?

If so I have a few of them siting right here on my desk. They could be in the mail to Wisconsin in the AM, heck even if no-one knows I'd send some just to try if 79josh81 could start a conversation with me with a mailing address.

Spec's on these are 1.3X2.5 mm

That would be cool but I have no idea if they’d work either. I just can’t understand how there isn’t an o-ring size that is standard for these mix screws. My only other idea is to somehow shape the rings on the mix screws now to fit into my carbs. Hopefully someone else chimes in. I can’t be the only one who’s ever had this issue.
 
Stock 78-79 carbs are the same.

http://www.xs650.com/threads/the-gr...ut-bolt-sizes-used-on-the-xs650-thread.51957/

xs650-carb-orings-jpg.139166


there I fixed it.
 
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The '76-'77 carbs are the same and had no o-ring on the mix screws. '78-'79 BS38s were the only 38s with an o-ring on the mix screw. We've found a better size now than the 1.5 x 3 I originally used, the 1.3 x 2.5 that kshansen mentioned. The 1.5 x 3 will work but is a very tight fit into the hole in the carb body. A bit may get shaved off the O.D. as you install the screw.
 
The '76-'77 carbs are the same and had no o-ring on the mix screws. '78-'79 BS38s were the only 38s with an o-ring on the mix screw. We've found a better size now than the 1.5 x 3 I originally used, the 1.3 x 2.5 that kshansen mentioned. The 1.5 x 3 will work but is a very tight fit into the hole in the carb body. A bit may get shaved off the O.D. as you install the screw.

So I need a 1.3mm x 2.5mm? Other than kshansen, where do you guys find stuff like this?
 
Lol...ok. That’s ok, my mind can handle anymore surprises after needing o-rings and finding out there’s an online store that’s solely dedicated to selling o-rings.
 
Lol...ok. That’s ok, my mind can handle anymore surprises after needing o-rings and finding out there’s an online store that’s solely dedicated to selling o-rings.
Well, while you may be thinking of Orings in the context of the tiny ones we are talking about here but in the industrial world they come in many sizes and many different types of materials. Even can be had in various colors!
 
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