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Discussion Starter · #1 ·
are these O-rings between the carb boot and cylinder head anything special? do i have get a special type that can stand up to the heat, or will one from harbor freight do the trick? none of the dealerships/motorcycle shops in my area carry anything close to the right size and i don't want to wait the week to order them.
 

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I just bought NOS ones from Honda and they are simply rubber. Nothing heat resistant here that I can see.
 

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The o-ring (factory) size is 40mm X 2.4mm. A slightly thicker replacement would be 40mm X 2.6mm.



In March of 2009, I purchased a pack of 25 o-rings from McMaster Carr (mcmaster.com) for $9.16 plus a little shipping (less than $13.00 total). These o-rings are 1-5/8" I.D. X 1-13/16" O.D. X 3/32" THK. They fit well & I may never run out. McMaster # AS568A Dash Number 130 .



 

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The NOS carb boots I just bought have a "slotted" circle groove in them that actually holds the gasket in place for you during installation. The old ones did NOT have this slotted feature (but did have the circle groove)and the gaskets were different. The new gaskets are rounded as opposed to flat which my old ones were (not sure if they were factory).
 

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Discussion Starter · #6 ·
dark father you just explained everything i have been dealing with. the PO must have put on NOS carb boots b/c they have a slot and then used the old O-ring which isn't thick enough for those boots. thank you.
 

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Paul said "These o-rings are 1-5/8" I.D. X 1-13/16" O.D. X 3/32" THK. They fit well & I may never run out. McMaster # AS568A Dash Number 130"

I have also used the #130 orings and they work fine. The #130 is their specification number. buna n material is fine for this application.
 

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Thanks Paul and Rich for the BTDT with the correct McMaster Orings, nice find.



For the record, the "square" Orings started out round. If they appear to be square, then they were probably a little too thick for the application.
 

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Paul said "These o-rings are 1-5/8" I.D. X 1-13/16" O.D. X 3/32" THK. They fit well & I may never run out. McMaster # AS568A Dash Number 130"

I have also used the #130 orings and they work fine. The #130 is their specification number. buna n material is fine for this application.


You can get these at any plumbing supply place for about $2. From honda it'll cost about $20 - $25.
 

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Just for clarification, the #130 is an industry standard designation, not just McMaster Carr. That number will find them at some hardware stores too. I don't think they are that costly from Honda, but sometimes a dealer isn't handy. I get mine from Bowman Barnes.
 

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And, they're $5.00 to $6.50 EACH from the Stealership.



Now we know where "Stealership" comes from.
 

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Yea, I took mine to the Ace hardware store and came home with a couple of new ones for 2.89. The old ones were hard and square and wouldn't seal good anymore.
 

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Go to any good plumbers supply shop and you will find a plethora of O rings you can match and use in most locations on the CX motors as they generally only use low spec O rings. However, dont do this for the 2 large "O" rings on the rear engine cover as these have an unusual OD and so most "o" rings that look similar will in fact break the gasket when tightened
 
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