K&B Break-in

[JonWid]

I rebuilt my K&B3.5 powerhead. Any suggestions on break-in? Fuel, needle settings?

Also, as far as prop balancers go, does the magnetic one from TopFlight work OK? I have a new Prather 215 to start out.

Thx,

Jon

 

[Mark Poole ModVP]

If you still have the K&B instruction sheet that came with the engine it outlines what to do and what not to do during break in. Basically, don't run it too lean and at the same time not overly rich either. It is a good idea to turn the engine over many times by hand with the plug out while keeping it very wet with WD-40. This helps prevent the initial "sticking" at TDC with a new piston and sleeve. You don't really have to run low nitro for break in. The TopFlite balancer works well, just make sure the face of the magnets are very smooth (you can wet sand them) and make sure the plastic framework is set nice and square. Preston Hall (IW member) made a limited amount of custom jeweled prop balancers. I have one of them and it is the best balancer that I have had so far.

Mark

 

[Ronald van Essen]

Jon

Prop balancers: there are a couple of them for sale from Octura, Prather or even Robart. I agree with JD, the one he has is top of the bill, but you can't buy it in a shop.

The trick with all the balancers is that you need to try and spin it with the least friction possible, so the prop turns on and on....

Ronald.