round tops vs keyhole

[pat english]

I know there has been a bunch of arguments about this but i just really want to know if the round top style carbs will work on my engine.Its a 78 k.the reason i ask is because i cracked a float bowl on my carbs and ruined another bowl,also destroyed the throttle valve on one of the carbs...anyways,my buddy has a set of round top carbs and boots he said i could have for $100.wondering if i should use these or try to find the parts for my carbs..

[shinyribs]

I have roundtops on my 76F and am pleased with them. I have zero tuning/rideability issues with them and my fuel mileage is great.Usually 45 mpg +/- 2 mpg.

I am putting together a 78K now,and I sold the keyholes that came with it to have the money to buy roundtops.

I have never used keyholes personally,and am sure they are fine carburetors,but i do know the roundtops can be used without any problems.

Tuning pods are a breeze with the roundtops,if you are concerned about that

[pat english]

allrighty.are the intake boots the same?

[TOOLS1]

No they are different. However, you can buy them new, for the roundtops, but not, for the keyhole.
TOOLS

[rrgunslinger]

If u can get them to fit they should work. You may have to tune them.  Give it a try and keep us posted. 

Harvey

On Jun 26, 2012 10:32 PM, "pat english [via Honda CB750'S]" <[hidden email]> wrote:

I know there has been a bunch of arguments about this but i just really want to know if the round top style carbs will work on my engine.Its a 78 k.the reason i ask is because i cracked a float bowl on my carbs and ruined another bowl,also destroyed the throttle valve on one of the carbs...anyways,my buddy has a set of round top carbs and boots he said i could have for $100.wondering if i should use these or try to find the parts for my carbs..

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NAML

[pat english]

ah.right on.ny bud said i can have the carbs and boots for 100.i think i might just go with those..and ill take my time on this set..learned my lesson about being impatient with carbs.Ill soak them for a week or so before i start taking them apart...
 sorry if this is a silly question but do the round tops have a cable going to each carb?

[Piute]

   NO
,I believe the 1st couple yr's (69/70) did .,By the way I have key-tops and work great,I'd use what you fill comfortable and how you plan to use,Yet to determan m.p.g. no speedo.

[shinyribs]

The '69 carbs had the 4 individual cables,the '70 and later had the lift fork setup. Both styles are round tops,they are just activated differently

[pat english]

ah,right on.well nothing set in stone yet..i found the correct throttle valve for my carbs,but having trouble finding float bowls..

[Re-run]

You can still buy the manifolds for the 77/78 k and f, A might be harder. They just sell 2 of them so you buy 2 of each and just flip 2 of them.

One thing is that the manifold rubbers on the 77/78 are larger than the earlier carbs.

Both carbs work well but I like the better acceleration of the keyhole carbs.

I get 45+ mpg of a mediocre tune on my carbs. If I tuned them better, it would be higher.

[pat english]

right on.well i pretty much decided to go with the round tops.my buddy has a complete engine with carbs that hes letting go for super cheap.im guna pic it up this weekend.