Homelite generator

I bought an interesting generator at the weekend from Matt the Sawyer (hi
Matt ;o)) ) It is a 1944 ex-USAF battery charging set. It is fitted with
suspension springs and sits on a rack-mounting platform arrangement that
leads me to believe that Matt might well be right in his assumption that it
was a type used as an in flight APU for Boeing B29's .
The model is HRU 28A constructed to specification 94-32313-A on contract
number W30-053AC-482. The serial number is 250404. It is a 28 Volt 70 Amp
dynamo. If at all possible, I'd like to know when it was supplied and to
Any clues, Gentlemen?
On Monday, I hauled it out of the car and was delighted to find that it is
mostly aluminium. A two stroke with die-cast close pitched finning and fan
cooling, it has a very neat WICO ignition generator and rope starting pulley
at one end of the crank and a direct drive generator at the other. It is a
nice piece of design work and considerable effort has been taken to ensure
lightness and ease of use. Of all the generators of this period I've seen,
this is by far the best designed I've come across and innovative use has
been made of available space with the control box and petroil tank being
tucked neatly away under the unit. The whole thing looks to me like a "clean
sheet of paper" design.
It had obviously not run in a long time, the tank no longer smelling of
hydrocarbons and having a mixture of rust and old paint inside it, which I
hoovered out! There was no spark as Matt had told me, although a meter on
all the components indicated that they all functioned OK and the coil
provided a spark when flashed with 12 volts. I'd cleaned the points
initially with wet and dry in situ without any improvement. However,
removing them showed a thick oxide layer that took 800 grit wet & dry on a
solid base plate to remove. That done, a spark appeared at the genuine
original shielded plug and a whiff of Gypsy's Breath down the carb made it
Reassembling the petrol tank to the frame, sealing and refitting the carb
took about an hour and then it was crunch time. It did rotate on the starter
button, but wasn't happy. Removal of the inspection plates at the commutator
end showed seized brushes and a blackened comm. It took another hour to
clean it up, but then 24 volts whipped it round at perhaps 1,500+ RPM.
It took quite a bit of winding to make the carb pull fuel up the long pipe,
but in the end it fired and ran well, settling down to a steady pace on the
carb adjuster screw. There was no charge from the leads, but investigation
showed a broken ammeter lead and fixing that produced well over 30 five
volts, regulated again according to speed at the carb.
I think the carb will benefit from a good clean, but aside from that it is
in good enough condition to respond to an oily rag restoration, "USAF" still
being stencilled onto the airforce blue paint of the petroil tank.
Thanks Matt, I'm very pleased with it. ;o))
Kim Siddorn
Reply to
J K Siddorn
Loading thread data ...
Try an ask on the 'sparks & arcs' bulletin board
formatting link
up with a few useful bits of info on my Delcolight set.
Reply to
Nick Highfield
We have an original Homelite manual for one of their units, I will check tonight and see if it is the same as your'n.
Kind regards,
Peter Forbes Prepair Ltd Luton, UK email: snipped-for-privacy@easynet.co.uk home: snipped-for-privacy@easynet.co.uk
Reply to
Prepair Ltd
Thanks Peter!
Kim Siddorn
Reply to
J K Siddorn
Plenty of hits on google for Homelite 'HRH 28' and 'HRUH 28' which appear to be auxiliary gennys for tanks, but nothing for 'HRU 28A'. A = airborne perhaps?
Reply to
Nick Highfield
Just checked the web pages, it is:
24A120-23 Gen Set Op + Spares
Looks different, but maybe enough is the same to be useful.
Kind regards,
Peter Forbes Prepair Ltd Luton, UK email: snipped-for-privacy@easynet.co.uk home: snipped-for-privacy@easynet.co.uk
Reply to
Prepair Ltd
Kim, What you describe was also used on B17's and also B24's. I restored one for Mary Alice B17G at Duxford it is as you describe an APU but only for ground use not used in flight. The one in the museums B29 "Hawg Wild" was a different unit and I can't imagine it being used in flight because the B29 was a pressurised aircraft and these things were inside also.
Martin P
Reply to
The unit is a 1-1/2kW 120V AC with flat topped cylinder head and spark plug sat in the middle. Fuel tank is at one end, exhaust runs down the side of the unit, four springs form suspension over the base skids, mine also has a blow torch for starting in cold weather!
Carb is almost built into the fuel tank, ammeter and voltmeter in the control box over the genny.
Sacnner is disconnected at the present time, but will endeavour to get you a pic sometime soon.
PS: Spares list and circuit of the genny are included.
-- Peter & Rita Forbes snipped-for-privacy@easynet.co.uk Engine pages for preservation info:
formatting link
Reply to
Peter A Forbes

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.