Carb question

[racejunkie538]

Hi

Hope anyone can help me out in finding a good O.S. carb witch will fit the K&B .67 OB,

I'm done with the carb who came with the engine :angry:

Thanx for reply

Gr Marc

 

[Bob Kensill]

Try the Picco .67 EXR carb. It is much better than the OS carb.

 

[racejunkie538]

krpnova

Thanx for reply, do you have an adress or website where to find ??

Any one some more sugestions for a good carb for my K&B .67 OB.

Gr Marc

 

[racejunkie538]

I know its hard to get a diverend carb for my K&B .67,

so does anyone have a good break in setup for the carb that comes with the engine,

specialy the high speed needle and what to do after break in ??

I allso like to know what shim do I need for break in and after break in.

Sorry about my english, hope you understand.

Greets Marc

 

[Jerry Wyss]

I'm surprised you haven't had more of a response here Marc. The last time I ran a big block K&B O/B was over

10 years ago,, but I used the Geraghty carbs most the time. I'm sure Rod Geraghty still has "something" that

will fit. All I have that will fit a 67 (older one) is the "CB" carb and it would not be my first choice if I was to run

another big block.

I used one O.S. carb once on a 67 but I just can't remember which one. Anyway, the Geraghty would be what I

would use and he "may" be able to tune the bore to your application.

As for correct "shimming", you will need to know what is the measured headspace in there now. With a K&B,

It can be almost anything. I assume you run low nitro in your fuel and I would run no less than .016" no more

than .022"

Needle adjustment can be as different as the needle you have in there. Normally I zipped the needle out 4 turns

and screwed it in until the head got warm (running it in the water). Run a couple laps, bring it in, feel for warm,

adjust needle and run again.

 

[racejunkie538]

Jerry

I was allso suprised, it seems like no one is running .67 K&B anymore. I know these are pretty old motors but they still run like hell and I love it.

I read an article from Rod about running at high altitude withe the Geraghty carb, so I can allways try to send him a message.

About the OS carb you have used, maybe is was the H6 or H8, heard some good results of it.

What about the right shimm, I have to measure first, have not done it yet, and yes I run 20% nitro in my fuel.

Do you recoment some higher % of nitro Jerry ??

The needle adjustment as you discribe, your talking about the high speed needle right ??

Greets Marc

 

[jaimy]

I'n also looking for a carb for my outboard

its a k&b .82

@marc

I hope we can race soon together

 

[Jerry Wyss]

JerryWhat about the right shimm, I have to measure first, have not done it yet, and yes I run 20% nitro in my fuel.

Do you recoment some higher % of nitro Jerry ??

The needle adjustment as you discribe, your talking about the high speed needle right ??

Greets Marc

Most of these motors are "nitro hogs", 30% would be better than 20 of course. A possible aid to measuring

headspace would be a product called "Plastigage", a soft filiment used by engine builders (full size) and mechanics

to guage clearence in engine main bearings and similar uses.

A 1" long piece is bended in a "L" shape and inserted into the glowplug hole, turn flywheel (starting cone) until the

piston comes up and smashes it between the piston & head. Gently lift it out (may get stuck to piston or head which

makes removing the head to get a reading) and compare the "flattened" area to the graded samples on the

edge of the package it comes in. You will need the "Yellow" lable Plastigage for you larger headspace measurements.

Plastigage may not be available over there, but it sure makes measuring headspace easy and accurate.

Yes, the info was concerning the "high speed" needle. The low speed adjustment is mostly for starting, throttle response

during running and reasonable running coming back to shore.

 

[SayMikey]

JerryWhat about the right shimm, I have to measure first, have not done it yet, and yes I run 20% nitro in my fuel.

Do you recoment some higher % of nitro Jerry ??

The needle adjustment as you discribe, your talking about the high speed needle right ??

Greets Marc

Most of these motors are "nitro hogs", 30% would be better than 20 of course. A possible aid to measuring

headspace would be a product called "Plastigage", a soft filiment used by engine builders (full size) and mechanics

to guage clearence in engine main bearings and similar uses.

A 1" long piece is bended in a "L" shape and inserted into the glowplug hole, turn flywheel (starting cone) until the

piston comes up and smashes it between the piston & head. Gently lift it out (may get stuck to piston or head which

makes removing the head to get a reading) and compare the "flattened" area to the graded samples on the

edge of the package it comes in. You will need the "Yellow" lable Plastigage for you larger headspace measurements.

Plastigage may not be available over there, but it sure makes measuring headspace easy and accurate.

Yes, the info was concerning the "high speed" needle. The low speed adjustment is mostly for starting, throttle response

during running and reasonable running coming back to shore.

Poor mans head gauge thin soft solder,bend a l shape slide it in the plug hole bump the motor over top dead center and measure with a mic or caliper

 

[racejunkie538]

Jerry

I will give it a try to use some more nitro the next run.

About measurig the head space, I think I will use the idea of "SayMikey" but thanks for give me the good advice.

The last time I run the K&B .67, the engine was into a hydro lock, because of picking up water

when hooking in a corner. It cost me a new rod but the rest seems OK. I'm thinking of using

some l bend air intake to avoid a next hydrolock. What allso is a criticalpoint to me are the small lubricate

holes in the rod. In my opinion there are to small to reach the correct effect. Do you think I can make them

a little bigger. Jerry, last question; what is a good brand of plugs to use, the best plugs available here are Rossi and OS

what do you recomend.

Marc

 

[Jerry Wyss]

Jerry
I will give it a try to use some more nitro the next run.

About measurig the head space, I think I will use the idea of "SayMikey" but thanks for give me the good advice.

The last time I run the K&B .67, the engine was into a hydro lock, because of picking up water

when hooking in a corner. It cost me a new rod but the rest seems OK. I'm thinking of using

some l bend air intake to avoid a next hydrolock. What allso is a criticalpoint to me are the small lubricate

holes in the rod. In my opinion there are to small to reach the correct effect. Do you think I can make them

a little bigger. Jerry, last question; what is a good brand of plugs to use, the best plugs available here are Rossi and OS

what do you recomend.

Marc

Of all the guys here I'm not the expert on the K&B motors, I only know what I did, and used. I have never used a Rossi

plug in anything, so I'm no use there. OS makes many plugs, (more than anybody) some like the OS8 have an "inbetween"

reach of all the other plugs, the A5 and such are similar in that same reach (I think). I used a "Long Reach" cold plug

(McCoy#9) in my 67.

I never ran a stock K&B 67 and it was at the time when the "RPM" rods were readily available so I put one of those in

when I disassembled a new engine, (something that was a must with a K& B)

I can't advise you concerning the "opening" of the "oil drillings" in the stock rod. I do know that the stock "dog bone"

rod in some of K&B motors were pretty tough for me,, they were "rounded" in they're shape.

The water entering the carb on my 67's was a problem until I started going faster,, once things were trimmed out and

running well it wasn't much of a problem anymore. I used a "snorkle" (air intake) at first (1/10 scale buggy part) for

the water going into the carb.

JW