K&B with ABC prop

[snowdog-2112]

K&B with ABC prop

All,

Setup: Leecraft xtr21 with k&b21 with irwin pipe and ABC H4 with 35% nitro.

The boat/engine is acting strange. In turns it picks up revs, and almost dies after making the turn, if i wiggle the rudder back and forth it picks up revs again and get on plane and then runs down again.

Any ideas? BTW, the propellor is about level with sponsons. Now here's the kicker, with a mod 1440 it runs fine. What's the deal?

Snowdog

 

[MarkScott]

Re:K&B with ABC prop

Think you need to sell everything to me!!! ;D

Mark..

OB Nut: look'n for a deal!

 

[Buddy Beaird]

Re:K&B with ABC prop

Too much prop!! How'd you get that h-4 under there?

 

[Slideblues]

Re:K&B with ABC prop

The H-4 is a hydro prop, lotsa revs, lotsa pitch, You reduce the dia to about 1.58 to clear. Sounds like the engine is lugging, Things to try, slight backcut, If your runnin propshaft level with sponson bottoms raise it up a little, like a 1/16" at a time, and test it again.

Its takes a lot of power to pull one,

Gene ;D

 

[snowdog-2112]

Re:K&B with ABC prop

Slide,

How about a CMB? Does it have enough power?

 

[Slideblues]

Re:K&B with ABC prop

Yeah it should, Just remember to run it high, let it rev, I run 60% here, so its hard to tell with the lesser percentages of nitro.

Try it and see

Gene ;D

 

[nitrotoys]

Re:K&B with ABC prop

Wayyyyyyy to much prop, I Have had real good luck running the X440-3 blade. I like that better than the 440 or 215 2 blades.

Sounds to me you are comming off the pipe and when you turn you free it up some and it gets back on.

and that 440-3 I run with a lightly modded CMB Powerhead on K&B lower, silver bullet pipe.

30 inch tunnel.

NT

 

[nitrotoys]

Re:K&B with ABC prop

I run a X438 on my stock .21 K&B.

40% nitro in both engines

 

[Slideblues]

Re:K&B with ABC prop

Here is a shot of the H-4 that I ran on my Villains, but they were VERY lite hull's, so weight will figure in too.

It does take a gentle touch at the controls to run a lite hull pullin that much prop fer sure

Gene ;D

 

[Ben Stein]

Re:K&B with ABC prop

I run a h4 on my CMB without any problems. No significant mods to the prop, only sharpened balanced and reduced diameter enough to fit my lower. I run it on a light tunnel and about 3/16" higher than the keelsons.

 

[Ben Stein]

Re:K&B with ABC prop

one would have to perform some serious surgery on a K&B 3.5 to make it powerful enough for a h4

My .02 euro (the other cent)

 

[snowdog-2112]

Re:K&B with ABC prop

All,

Thanks for the thoughts and opinions on this. I was thinking the prop was to big and that was causing most of the problems.

OBNut, sure...I'll trade everything I have right now for those 5,000 Solutions. Payable tomorrow! ;D

Gene, something like that.

Nitrotoys, I prefer the smaller props...let's the engine rev up nice and the hull handles well.

Ben, talk to OBNut about K&B engine mods. I think he's onto something. By the time he's done cutting away all that material, I think the engine's gonna weigh 50% less. OBNut, I figured out why the mods work, it's not that the engine is more efficient, it's that the whole thing is lighter.

Thanks all,

Snowdog

Team Snowdog - Learning from others to better the cause of the team. In turn, using that info to help others.

 

[lohring]

Re:K&B with ABC prop

Most of the fast Leecraft XTR-21s I know about run a 1440 cut back and cupped. Some people run the X440, but I don't think it's as fast. The stronger engines like the Nova Rossi, CMB, and MAC can pull larger diameter props. See www.BandMLeecraft.com for setup tips.

Lohring Miller

 

[XtremeRcBoats]

Re:K&B with ABC prop

Ok Bryan asked around for my leecraft. Gene told me about his H4 some time ago so i thought i'd give it a try.

I already had to reduce the diameter a little to fit under the cavitation plate. The pond we were running was a bit small and it looked once or twice i finally picked up, but then i was at the end of the pond. Best resuls so far are indeed with a mod 1440, a prop that didn't work on bryan boat.

 

[Slideblues]

Re:K&B with ABC prop

Hey Paul,

Nice to see ya here, Check in more often my friend ;D

Gene 8)

 

[XtremeRcBoats]

Re:K&B with ABC prop

So i guess i keep this thing in the box till i maybe someday get an cmb or something similar.

 

[Slideblues]

Re:K&B with ABC prop

Paul,

With the hard to get and pricey K&B parts in Europe it would be expensive to mod out your 8907 to run a H4 with your LeeCraft. If you built up a 28/30 WOF, something very lite maybe.

Other power heads to look for a deal are as you said CMB, NR, or Mac. Its a great prop for Hydro or Riggers too,

Gene ;D

 

[GTR]

Re:K&B with ABC prop

Hi Paul,

A guy in the US is selling Rossi (Gold head) 21 OB powerheads at the moment on Ebay for $200USD. I've got a couple coming because of the support from K&B.

GT ;D