Carb Rebuild Kits

[catcolkat]

Hi All

Getting ready to start the restro,  1978 CB 750 K, looking to order a set of carb kits
and was hoping to get some insight on how complete the kits should be and where to buy?

Also in the market for a front fender, mine has a big dent right up front on the right side.
My plan is to rechrome the fender.

Thanks in advance.

Webster

[TOOLS1]

The only parts needed to rebuild your carbs are the float bowl gaskets (get the pre molded ones), the 6-10X2mm O-rings for the fuel tubes, and the 4 little O-rings on the fuel screws, and maybe the accelerator pump. Just be sure to remove the pressed in pilot jets to clean them (you might want to take the time to drill them out to 0.45mm this will make the bike start easier, and run cooler) . There is a write up on removing them in the tips section. Another thing to check is the 2 very little ball valves in the No#2 float bowel that operate the accelerator pump circuit.
TOOLS

[catcolkat]

Thanks Tools for the info.

 

Where is the best place to buy the carb kit and the part to rebuild the accelerator pump ?

 

What am I looking for or checking for with regards to the  2 very little ball valves in the No#2 float bowel that operate the accelerator pump circuit.

 

Thanks

 

Webster

---

From: "TOOLS1 [via Honda CB750'S]" <[hidden email]>
To: "catcolkat" <[hidden email]>
Sent: Saturday, August 31, 2013 7:40:14 PM
Subject: Re: Carb Rebuild Kits

The only parts needed to rebuild your carbs are the float bowl gaskets (get the pre molded ones), the 6-10X2mm O-rings for the fuel tubes, and the 4 little O-rings on the fuel screws, and maybe the accelerator pump. Just be sure to remove the pressed in pilot jets to clean them (you might want to take the time to drill them out to 0.45mm this will make the bike start easier, and run cooler) . There is a write up on removing them in the tips section. Another thing to  check is the 2 very little ball valves in the No#2 float bowel that operate the accelerator pump circuit.
TOOLS

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NAML

[Lucky 1]

Tools is right on except one thing.... DO NOT drill the jets out to that size(45mm).

They will be too large. You will need #42 idle jets if you have pods and aftermarket exhaust.
Also if you have pods and aftermarket exhausts you need to move the clip DOWN one notch and since this bike has non adjustable slide needles you will need to shim them with a washer or get 1976 or 1977 adjustable needles.

The bottom check ball in the accelerator pump is the problem one.
Water and debris collects there and the steel check ball can get corroded and not seal.
IF the seat is corroded you will need to get a new bottom plate with check ball.

[catcolkat]

Hi Lucky thanks for the reply

I have purchased the carb rebuild kits & the carb pump diaphragm   

http://www.z1enterprises.com/ItemDetails.aspx?item=SIKH-1157

 

http://www.z1enterprises.com/ItemDetails.aspx?itemDescription=Carb+Pump+Diaphragm+Set+CB450+CM450+CB750&item=KL18-2807

I have no aftermarket anything on this bike and I am planning on keeping it as close to stock as possible.

I have NOT opened up the carbs yet so I don't know about the check ball in the accelerator pump.

If the seat is corroded and I need  to get a new bottom plate with check ball, where will I go

to purchase them ?????.

 

Webster

---

From: "Lucky 1 [via Honda CB750'S]" <[hidden email]>
To: "catcolkat" <[hidden email]>
Sent: Wednesday, September 4, 2013 12:21:28 PM
Subject: Re: Carb Rebuild Kits

Tools is right on except one thing.... DO NOT drill the jets out to that size(45mm).

They will be too large. You will need #42 idle jets if you have pods and aftermarket exhaust.
Also if you have pods and aftermarket exhausts you need to move the clip DOWN one notch and since this bike has non adjustable slide needles you will need to shim them with a washer or get 1976 or 1977 adjustable needles.

The bottom check ball in the accelerator pump is the problem one.
Water and debris collects there and the steel check ball can get corroded and not seal.
IF the seat is corroded you will need to get a new bottom plate with check ball.

---

If you reply to this email, your message will be added to the discussion below:

http://honda-cb750-s.456789.n3.nabble.com/Carb-Rebuild-Kits-tp4045331p4045389.html

To unsubscribe from Carb Rebuild Kits, click here.
NAML

---

From: "Lucky 1 [via Honda CB750'S]" <[hidden email]>
To: "catcolkat" <[hidden email]>
Sent: Wednesday, September 4, 2013 12:21:28 PM
Subject: Re: Carb Rebuild Kits

Tools is right on except one thing.... DO NOT drill the jets out to that size(45mm).

They will be too large. You will need #42 idle jets if you have pods and aftermarket exhaust.
Also if you have pods and aftermarket exhausts you need to move the clip DOWN one notch and since this bike has non adjustable slide needles you will need to shim them with a washer or get 1976 or 1977 adjustable needles.

The bottom check ball in the accelerator pump is the problem one.
Water and debris collects there and the steel check ball can get corroded and not seal.
IF the seat is corroded you will need to get a new bottom plate with check ball.

---

If you reply to this email, your message will be added to the discussion below:

http://honda-cb750-s.456789.n3.nabble.com/Carb-Rebuild-Kits-tp4045331p4045389.html

To unsubscribe from Carb Rebuild Kits, click here.
NAML

[TOOLS1]

I stated "drill them out to 0.45mm" not 45mm. That's over 2 inches.
TOOLS

[Lucky 1]

Bike Bandit has most everything. The bottom plate with check ball for the 1978 CB750K  is about $50. but it will not run very well with out that.

If you have the opportunity... get 1969 carbs for it, and you will not have nearly as many problems.
The 1969 carbs are fully adjustable with the carbs ON the bike.
All of the jets screw in.
The choke is a simple flip up or down lever.
No throttle shafts or lifter arms and all of those extra parts.
Just 4 simple carbs.
Each carb has an idle knob with closed position clearly marked.

[Lucky 1]

"I stated "drill them out to 0.45mm" not 45mm. That's over 2 inches.
TOOLS

LUCKY -Yes the decimal point is in the right place but what I was trying to say is that
0.45 is too large! See what I mean. I have tested that on the 1978 CB750K. It is way too rich.
That idea comes from the CB750 choppers website.

.45mm=17.71 thousandths or almost .018 thousandths.
.42mm=16.53 thousandths or almost .16-1/2 thousandths.

Makes a big difference.
Maybe it worked on earlier models ...don't know. I would have to actually test that.


I was not quibling about the decimal point.
The jet itself just has #42 or #45 stamped on it. No decimal point.

[TOOLS1]

I have drilled three sets of jets out to .45mm recently. They are in two sets of matic carbs, and one set of F carbs. No problems with any of them. They start easier, and the pinging/knocking is gone. From now on anytime I pull a set of those jets, they are getting drilled.
TOOLS