Topic: Carb Kits

[MikeSimon]

A friend of mine has asked me to do his 750SOHC carbs. What is the recommended kit out there. Don't know if I need jets. Would like to maybe clean and reuse the originals. Would like to replace the float valves, though. Based on my experience with the CBX CV carbs.

[dave500]

keyster kits are common but don't trust the brass to be correct dimensions,lots of people have complained about them,soak your old brass in vinegar to clean it up then 0000 steel wool.

[ekpent]

  After doing a ton of 750 carbs the only floats I have ever found bad were a couple of the early brass (K0-K1) that were leaking/broken. I have never bought a carb kit in my life and also have never had to replace a stock float bowl gasket. Had to replace some aftermarket. I just leave the old originals in place even during a dunk. The aftermarket rubber ones are crap and like to swell and do other nasty stuff. Unless your doing a carb tune for pods or something clean and re-use all the old stuff if original Keihin or the bike was at one time running well.

[Yamahawk]

  After doing a ton of 750 carbs the only floats I have ever found bad were a couple of the early brass (K0-K1) that were leaking/broken. I have never bought a carb kit in my life and also have never had to replace a stock float bowl gasket. Had to replace some aftermarket. I just leave the old originals in place even during a dunk. The aftermarket rubber ones are crap and like to swell and do other nasty stuff. Unless your doing a carb tune for pods or something clean and re-use all the old stuff if original Keihin or the bike was at one time running well.

Good to know, as I will be pulling the carbs on my 1971 CB750K1 this winter, and cleaning/refurbing them. Thanks!
Charlie

[Ace Blackwell]

I'm doing mine this winter as well. I've read about the dip.  Are you saying you don't need to tear down carbs, just dip whole (individual carb) ?  or do I need to tear down to jets and the like?  Do I only dip certain components. IE bowls, bodies, bolts.  I've read original hardware is best way to go.  I don't want to damage needles and ports by pitting / weakening them accidentally. - Thx

[ekpent]

 You should strip down the carbs prior to dipping like the jets,floats,float needle and seat air screws,slide etc. If the carbs are really varnished up on say an early 750 then I will go ahead and break down the bank of four and soak each body separately. Since I use the gallon cans of dip unfortunately whole banks do no fit. When I removed the carb body from the dip I immerse in a little warm water with a tad of soap in it then blow out thoroughly  with compressed air. Later I will prove the passage are clear with aerosol carb cleaner. Sometimes if the carbs are relatively good you can get by cleaning the components and not break the bank apart. These tips are for early 750 carbs other makes may/will be more difficult.

[PeWe]

I have done mine. I do not know how they will run. http://forums.sohc4.net/index.php/topic,168243.msg1966314.html#msg1966314
I used Cruzinimage kits I had ordered before. Could not resist to order since it cost only 40 USD for all 4 plus shipping
https://www.ebay.com/itm/Honda-CB750K-K1-K2-K3-K4-K5-K6-Carb-Repair-Kits-4-Repair-Kits-Include-48-1912-/162244633564?vxp=mtr&hash=item25c688a3dc
I used the float bowl and top rubber gaskets + float valves + pilot jets.

My needles and air screws are OK so I did not need to use them from the kits. 110 main jets included too.
I'll use 115 so i ordered separate sets of keihin mains.

[Ace Blackwell]

Good advice.  Im sure I'll ask for more once I start tearing down.

[madmtnmotors]

I used Cruzinimage kits I had ordered before. Could not resist to order since it cost only 40 USD for all 4 plus shipping

I was not so lucky. I have the later PD carbs (K8 CB750) that use the rubber tipped float needles. Using C.I.'s float needles and bowl gaskets my carbs started leaking profusely and the bowl gaskets turned to goo after just one week of exposure to 10% ethanol laced fuel. My recommendation is to verify that the rubber parts are Viton rubber or use original Honda parts. As others have suggested, reuse the original brass or find original Honda brass replacement parts if needed.

[PeWe]

I used Cruzinimage kits I had ordered before. Could not resist to order since it cost only 40 USD for all 4 plus shipping

I was not so lucky. I have the later PD carbs (K8 CB750) that use the rubber tipped float needles. Using C.I.'s float needles and bowl gaskets my carbs started leaking profusely and the bowl gaskets turned to goo after just one week of exposure to 10% ethanol laced fuel. My recommendation is to verify that the rubber parts are Viton rubber or use original Honda parts. As others have suggested, reuse the original brass or find original Honda brass replacement parts if needed.

The float needles in my kit for the K1-K6 carbs are not rubber tipped. I hope the rubber gaskets are better than the carb boots  they sell. Cracked within a few months, 2-3. 5% ethanol Shell V-power.
If I complain,  I guess  they will bann Sweden;)
All rubber parts in contact with fuel or oil, use Honda parts except for oil and fuel lines that must be made in a civilized country like USA, UK  or Germany where they produce such stuff.
I hope Cruzinimage brake lines are Ok.
I intend to install the upper line on my K6 when I replace the handlebar (2.5" higher) and have not long enough ss line on hand. On my k2 build, the complete Cruzinimage brake line kit.