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..maybe we should do a thread on the K&B's ..what do you say Razor?

Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

..maybe we should do a thread on the K&B's ..what do you say Razor?

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Old 04-03-2008, 08:02 PM
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Razor-RCU
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Default ..maybe we should do a thread on the K&B's ..what do you say Razor?

Here goes- We got K&B 7.5CC DF engines and we need tutelage...

Thoughts?
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Old 04-03-2008, 08:43 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

I'm in...
Would also like to get some opinions on propping a DF 7.5 for use in my Sonic (and perhaps other planes ) after the somewhat tired 6.5 decides that it's had enough.

P.S. Razor...did that little red box arrive yet?
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Old 04-03-2008, 08:54 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

I live right down the street from K&B!
I just walked the factory with the owner! (Randy)[X(]
Cool dude![8D]
Ten's of thousand's of piston's, casting's, crank's and complete engine's!
Stepped on my tounge numerous times while walking the factory!
Asked him to adopt me!
Got no response![>:]
But, he didn't say no either!

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Old 04-03-2008, 09:04 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

Cool!
Maybe you could be our "connection" for the brotherhood [8D]
Ask him to make a one piece crank for the 6.5's
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Old 04-03-2008, 09:19 PM
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SPEED JUNKIE
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

Somehow I knew that was going to be the next post![sm=thumbs_up.gif][sm=thumbs_up.gif]
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Old 04-03-2008, 10:46 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

Wayne is SOO popular. Somehow I think his focu in on a larger disp. engine than the 7.5CC
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Old 04-03-2008, 11:15 PM
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SPEED JUNKIE
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

What do you think about a 20.5 cc glo ducted fan engine spinning a new 7" ducted fan?[X(][X(][X(]
Me too![sm=tongue_smile.gif][sm=tongue_smile.gif][sm=tongue_smile.gif]
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Old 04-03-2008, 11:18 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

What the hell you gonna fly with a 7" freakin' fan???????? [X(]
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Old 04-03-2008, 11:27 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

MMMMMUUUUUUUUUUUAAAAAAAAAAHHHHHHAAAAAAAAA!
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Old 04-04-2008, 12:13 AM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

Great questions Tom! hahahahahahahahah................Just wait-

Can someon help me with the 20.5CC part? Is that like a 1.05?

Wayne?
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Old 04-04-2008, 12:25 AM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

No little red-box yet...
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Old 04-04-2008, 12:31 AM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

That's a 1.20 Razor!
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Old 04-05-2008, 04:56 AM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

just a question for you guys..I am only use to using composite/nylon props, but a while ago I picked these up just for curiosity sake, do you think any of these would be worth trying..I dont know much at all about wooden props ..but these things aere so light compared to APC's

2 off @ 9,1/2 x 8, 1 off @ 9,1/2 x 8,1/2 and las tone is a 9 x 9, these are old topflyte props labelled pylon racing..although they dont seem to be of the size I normally see for pylon engines

I am also thinking of using an APC 8.75 x 7.75 N to break in the K&B 7.5

any thoughts?
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Old 04-05-2008, 10:24 AM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

The wood props were considered "blanks". Nobody ever raced with a stock prop, but would spend an hour or two cutting them down, repitching, and reshaping the airfoil. And usually, they started with Rev-Up props.

But you can get pretty good performance just by cutting the length down, smoothing the tips, and balancing. You want to get the engine up to it's powerband, which for the 6.5 K&B was around 21,000-21,500. Never ran a 7.5 but the guy that did at a race is long gone. Not from being caught, just old age.
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Old 04-05-2008, 03:31 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

I just came in from running my 7.5 on a 8.75x8 APC prop. The high speed needle "self-adjusts" when wide open....I am not how to keep it from moving, most engines have that clip in the needle valve, anyone?
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Old 04-05-2008, 05:18 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

A piece silcone fuel tubing slipped over the needle.
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Old 04-05-2008, 07:58 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

You tighten the nut. If it's a new needle, you might have to do this a couple of times before everything seats.
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Old 04-05-2008, 08:14 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

You're talking about a Perry carb, correct?

The O-ring or bit of plastic/rubber (? ) that's inside the needle's knurled outer part gets hard and allows slippage...[]
That is one thing that I have yet to find a sure fire cure for...you can replace the idle disc O-rings, but I don't know if there's a way to fix the needle or just replace it.

When I put my Perry equipped engines away for storage, I unscrew the needle so the O-ring isn't in contact with anything, and try to keep oil from getting near it, but that's kinda difficult

Try cleaning things reeeaaallly good with something that doesn't leave a residue, like acetone, or brake parts cleaner.

If that doesn't work...either a new needle, or???

I've been thinking of maybe soaking just the needle in something that will swell the rubber a bit, then cleaning it well again?

I have yet to try and see if there is a way to remove the hardened bits and replace like the little O-rings on the idle disc.
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Old 04-05-2008, 10:53 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

My bad. Thought you have a venturi.
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Old 04-06-2008, 12:25 AM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

thanks for the reply, HighPlains..I know I have to cut them down and of course re balance them..I know somewhere here I read somewhere about dipping them in CA, or are they alright to run as they are after trim and balance?...I going to run my K&B at about 22,000 for breakin...hopefully
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Old 04-06-2008, 08:33 AM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

If you have shaped the entire blade and have a raw wood surface, then drip on a little CA on the blade and quickly wipe with a paper towel to cover. Then a light sanding with 600 paper to smooth and repeat the CA again. After the second time just lightly polish out with steel wool or even the backside of sand paper. It will be fuel proof and quick to do. The reason for quick to do is so it can be run up and if not yet there, more wood taken off.
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Old 04-11-2008, 10:44 AM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

Anything new Haveblue? It was pretty funny when my wife came out to the "shed" when I was running the 7.5 and I was wearing my old shooting earmuffs and eye protection...I never am THAT safe-

I bought a couple 9x6's for break-in. Have not had a 9x6 since the 1980's
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Old 04-11-2008, 11:58 AM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?


ORIGINAL: Kmot

A piece silcone fuel tubing slipped over the needle.
yep... thats it

The older perry carb had a spring to tension the needle. putting a silicone piece over the needle so it squishes to the low speed mixture disk worked better than the spring.
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Old 04-11-2008, 05:39 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

still waiting for a new pipe for my K&B..have had a month off between jobs, just started a new one wednesday just gone, so things have become a bit busy..also recieved a replacement piston, sleeve and rod for my ST .45 which I want to do some porting with to trial if modding an engine is worth it..need to take some readings as I intend to play with timing both crank and sleeve.

I might try to run the K&B open exhaust ..so later today I'll cut down one of those wooden props and give it a go.....

I've got a shallow little indent on my Whip, near the leading edge so I want to get some filler before I paint it...I love painting stuff..mostly cars, but comming up with a good scheme for a aircraft is really hard for me

as this is my first run with a DF engine and a wooden prop I think I might try the safety sheild too...something I haven't done before either.

as for APC props I've only got a 9 x 4 on hand that I wanted to use as a break in on my Irvine .40 FIRE..dont know if thats ok to use on the K&B might be too light a load
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Old 04-11-2008, 07:50 PM
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Default RE: ..maybe we should do a thread on the K&B's ..what do you say Razor?

I've got a 6.5 that has two head bolts broken off. Any one got a trick for getting those out? There is a small nub of the bolt sticking out but not much I don't want to round it off and be lost.

Thanks, Terry
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