K&B 7.5 ducted fan
- Thread starter dhal22
- Start date
jbeech
30cc
Why haven't you posted the rest of the photos? The engine comes apart quite easily. No getting it wrong. Nothing to damage. If the sleeve won't lift up easily, insert a bit of Popsicle stick in the exhaust port and use the itself piston to free it (don't use pliers on it, just your fingernails/fingertips). And being an ABC design, there's no ring. Anyway, once the sleeve is out, slip the big end of the rod off the wrist pin and pull the front section to remove the piston assembly. I don't recall if there are nylon buttons fore/aft covering the wrist pin but if there are, dig them out with a t-pin or the tip of an X-Acton with #11 blade - you won't hurt them. Then press the wrist pin out to separate the piston and rod for photography. As for the crank, it presses out lightly. The bearings will fall out with a slight bit of heat on the housing from either 30-minutes in an oven at 350°F, or by using a MAP-gas torch flame around their circumference on the aluminum housing. Finally, replace with new ones if you feel 'anything' when you rotate them, and reassemble after photos. For those unfamiliar with fuel and its effects, the brown stains are from castor oil. You can remove these by cooking the parts in antifreeze using a crock pot, or polish them off with a 3M white non-woven pad (looks like an extremely fine version of what's used to scrape pots and pans if you look at it with a magnifying glass). Note; be careful doing it this last way as it 'will' remove metal. Anyway, look for 3M part number 48011169767 which is readily available in single sheets (although we buy it by the box). You can buy them from the usual suspects, e.g. MSC, Mcmaster, etc. These are nicely made engines. I've done this disassembly so many times I honestly think I could do it in my sleep - easy-peasy!
pawnshopmike
Staff member
They made a lot of nice outboard motors too if I remember correctly.