Topic: 77-78 CB750 F2-F3 Reproduction carb boots and other Honda rubber bits!

[brandEn]

Just found this site and he offers some rare hard to find Honda rubber bits including the very hard to find 1977-1978 CB750 F2 carb insulators for only $89. They are towards the bottom of the page.


http://www.claussstudios.com/id45.html

[Tugboat]

Ooh, and the rubber tube that connects the carb to airbox on a Dream. Nice find!

[brandEn]

Ooh, and the rubber tube that connects the carb to airbox on a Dream. Nice find!

nice

[750K]

Anyone know if the 77-78 f carb boots are the same as the 77-78 k's? I know the part numbers are different but not sure if the boots can be used between models.

[martin99]

'Anyone know if the 77-78 f carb boots are the same as the 77-78 k's? I know the part numbers are different but not sure if the boots can be used between models.'


No they are not the same, the K7/8 ones are shorter and of a slightly different profile. However they can be used on a F2/3 if you are using aftermarket filters, but will not work with the standard airbox set-up.

[brandEn]

Bump for another member

[70CB750]

A related question.  What boots to use for F2 engine and K style carburetors?

[madScientist]

Has anyone tried these insulators? If so, what's the quality of them? Are they as good as the OEM?

I figured I'd open this thread back up instead of start a new one...

[bytio]

I have ordered some and expect delivery this week, I will report back when fitted.

[ZanVooden]

Yes, I just replaced these on my 78F. They are great quality. They fit exactly as they should. Easily as good as OEM in my opinion.

[Foolproof]

Yes, I just replaced these on my 78F. They are great quality. They fit exactly as they should. Easily as good as OEM in my opinion.

Nice to hear. I have some otw. 

[MRieck]

My only question is is the material fairly stiff. I ask because I have dealt with other reproduction insulators that were to flexible and really pulsed at idle. There were vacuum leaks and if you attempted to tighten the clamps more the leaks would become worse. The insulators I used were NOT from this company that is why I ask.

[cb750f2Mtl]

I have bought those , from Clauss Studio , and after 1000 km , they have melted..... Carb disconnected while riding ... ...

Sent an email the Clauss studio, will see with them.

[nolaw09]

Hey first time posting because I tripped over this article searching for carb boot options.

I had also bought Clauss' carb boots too and the things roasted. Called him up and he basically said "yeah these thing have been a pain and I had to stop making 'em" and he gave a full refund.

Went out again to scour the web for some alternative and found that one of those CB750 supply kind of websites just started selling some... Its the only option I've seen in forever so I just placed an order. $99... we'll see how they perform. Hoping they're the answer.

http://www.vintagecb750.com/products/86/new-items

I'll try to report when I get em in.

[harisuluv]

I was just about to say that its easy to make the form fit exactly right, it's the material they are made out of that's important.

[KayOne]

I purchased a set a few weeks ago from Vintage CB750.  The packaging has a small sticker indicating that they were made in Taiwan.  The castings appear to be identical to the stock isolators except the cylinder number characters are smaller.  I have never seen new Honda isolators but this set is extremely shiny.

[cheftuskey121]

I know it isn't much, but I've put 850 miles on my 78F with these new boots from the original link. nothing warped or roasted so far. it has been cold though, hasn't been running in the hot sun. hopefully they hold up

[nolaw09]

I was just about to say that its easy to make the form fit exactly right, it's the material they are made out of that's important.

On that note, would anyone know what would be a good material would be to make these out of? I would be down to replicate some new ones with a mold and make em with the correct rubber...?

but this set is extremely shiny.

Shiny kind of worries me, are they super soft? Plan on installing mine within the week when they arrive in mail

[jmac851]

There is a Japanese company selling them on ebay for 35 dollars and 12 dollars shipping.

[bytio]

Do you have a link to the item?

[KayOne]

I was just about to say that its easy to make the form fit exactly right, it's the material they are made out of that's important.

On that note, would anyone know what would be a good material would be to make these out of? I would be down to replicate some new ones with a mold and make em with the correct rubber...?

but this set is extremely shiny.

Shiny kind of worries me, are they super soft? Plan on installing mine within the week when they arrive in mail

They are at least as firm as the new boots I bought from Honda for my DOHC a couple of months ago. Who knows what thermal cycles will do to them though.

[KayOne]

Mocked up my F3 PD42 carbs to the K1 head today with the F2/3 boots from Vintage750. As expected, no mismatch problems to the smaller K intake spigots but no so to the carbs. Check out the area to the left and lower right to see the extent on the mismatch. All holes had similar mismatches of approximately 260 degree around the circumference.




BTW  I am planning on running the PD keyhole carbs on my 836 build for the accelerator pump option. I'm also hoping the waist shape of the Keyholes give me better throttle response down low...after reading all the anti cam threads lately. The Honda K intake clamps do a good job sealing the larger F boots to the smaller K spigots.

[seanbarney41]

That looks like a pretty bad performance stopper, K1.  However, the stockers are not much better.  Rubber is easy to trim with a sharp razor and or a dremel/die grinder.  If you are familiar with the earlier round tops, I doubt you are gonna realize any gains or benefits from those pds.

[Black 750K8]

I know it isn't much, but I've put 850 miles on my 78F with these new boots from the original link. nothing warped or roasted so far. it has been cold though, hasn't been running in the hot sun. hopefully they hold up

This is the link from the OP.
http://www.claussstudios.com/id45.html
I thought they stopped selling them maybe you got them before they stopped. Or did you get them from here?
http://www.vintagecb750.com/products/73/featured-products#product-48-0757

[KayOne]

Update:

 I now have the bike running and only have put on less than 20 miles (spring will not come!). They seem to seal well but while I was synching the carbs I observed that the boots are so soft, that you could actually see them pulsating with each induction cycle. They are so short that I doubt that they would collapse at WOT though. They seem to hold the carbs OK so hopefully they will last.

 BTW, I also bought a set of K0-K6 isolators from Vintage CB750 and could not get them to seal with the round top carbs. The recess for the band clamp on the engine side is too far out and only captures the very edge of the spigot...$100 down the drain.