Brief History of the Marque: JAP
J.A.Prestwich was responsible for the design and manufacture of engines
used in a great many famous marques and had numerous racing successes.
JAP engines were still used in speedway bikes well into the 1960's. Complete
motorcycles were built from 1904 to 1908, and subsequently the factory
concentrated on supplying its proprietory engines to other manufacturers.
After 1945, production was taken over by the Villiers
factory.
The extensive list of manufacturers which used JAP engines includes
Acme,
AJW, Alldays & Onions, Argentre,
Ariel,
Atala,
Austral,
Automoto,
Bown,
Bücker,
Brough-Superior,
Brown,
Calthorpe,
Corah,
Cotton,
Coventry-Eagle,
De-De,
DMW,
Dollar,
Dunelt,
Eysink,
Favor,
Fusi,
Ganna,
Grindlay-Peerless,
Hagon,
Imperia,
Invicta,
La
Mondiale,
Lea-Francis, Majestic,
Matchless,
Meray,
MGC,
New
Imperial, New Map, Nut,
OEC,
OK-Supreme,
Onoto,
Osa-Liberty,
Radior,
Rex-Acme,
Rover,
Rovin,
San
Sou Pap,
Soyer,
Stylson,
Terrot,
Tornax,
Trump,
Ultima,
UT,
Verlor,
Vindec,
Wolf,
and
Zenith.
JAP engines were also used in a wide range of industrial and other non-motorcycling
applications including railcars and early Reliant 3-wheelers.
Wed Feb 27 2008
comeon7s<at>gmail.com
JAP Engine parts available !!
jap all models
Here is a web site for J.A.P parts and complete engines ...for
bikes,morgans,airplane
http://www.cameronracingengines.com/
great white north
Wed Feb 06 2008
micheal.atkinson<at>btopenworld.com
jap engine
jap sv v twin
hi i have a jap sv v twin engine 750?.i can not find any numbers stamped
on the cases.there is a number on the brass arm on the lift at the top
of the crank case on it is 3130511. thanks for in identifying the engine,
model ect,,
derbyshire uk
JAP_Vtwin_Derbyshire.jpg will be posted shortly.
Fri Dec 28 2007
lencam<at>bigpond.com
JAP Spark Plugs
I am looking for new replacement spark plugs to suit a 1947 JAP 5 Stud
Solo 500cc engine.
Are there any new equivalents for the old Lodge R49 methanol plugs?
They must have 3/4" reach with internal electrode & heat range to suit
methanol.
Brisbane Australia
There may be some information on our fledgling
page about Classic Motorcycle Electrics.
Sat Oct 20 2007
neatheryt<at>sbcglobal.net
JAP in the movies
Unk.
In the movie :"Lawrence of Arabia" the actor is shown mounting a cycle
on his last ride. The letters on the engine are JAP, but what is the bike?
USA
I don't know which bike was actually used in
the movie, but TEL died following an accident on his Brough Superior. Ed.
Wed Oct 17 2007
stubbs785<at>btinternet.com
information about J A P engine
JAP v twin side valve engine number 32198
has any one any information about this engine? please
manchester
Thu Sep 20 2007
ramavneri<at>013.net.il
a rare v engine jap
1911 to 1914?
hi,
i have an old frame and v engine (1000 cc.) of a jap motorcycle.(1911-1914?)
i need a matching gearbox and the part that gives the spark to the
plug.
i need all kind of info of the engine and the other parts.
thanks in advance,
Ram
Israel
21st Sept 2007
subject: Sheldon EMU
Email: toddjayporter<at>aol.com
message: Hello,
I have been scouring the interenet for information regarding a bike
that I am helping a friend sell. He owns several vintage motorcycles, however
this one in particular has been a bit difficult to seek information on
ie: value etc...
This bike, JA Prestwich Speedway is owned by my friend who acquired
it in the early 1950's from a raceway in NJ.
The bike is in it's original condition and has several extremely rare
characteristics that I think would be of interest to a prospective owner.
Before I waste time going any further, I would like to ask if you have
any knowledge of websites and or locations that would have interest in
this rare bike.
I would appreciate your reply either way and in advance thank you for
your assistance.
Unfortunately I have tried to forward this message to Sheldon EMU and
the server has timed out. This is where it guided me to.
Todd Porter
NJ (USA)
Tue Sep 18 2007
spyker<at>aon.at
Jap school project
JAP IY/I 1927
Hello!
I need a information about an jap motorcycle engine from the year 1927.
The motor code is IY/Y. We have to restore these engine for a school project.
I now that the first I stands for 350ccm (70x90). The second I stands for
the year 1927. But for what is the Y. I read that it stands for twoport
exhaust. But my engine just has one exhaust.
I also speake German!
Thank you very much!
Austria
Thu Sep 13 2007
kflc<at>bigpond.com
Crank pin tightening torques required.
JAP 600cc mark 3 type 5
Hi there, can anyone supply a torque value so I can correctly tightn
the crank pin nuts after centering the crank flywheels.
Australia
Fri Jul 27 2007
wilkglenn<at>hotmail.com
Jap engines morgan cars
Was an early morgan car ever produced with a Jap engine?
Australia
Yes, Morgan JAP's were built during the 1930's.
Ed.
Sat Jul 14 2007
swords<at>bigpond.com
JAP motor
F/E28549D 1922 300cc
Have above motor fitted to 20's Triumph frame. Need forward facing
magneto chain case, inner/outer.
Sydney
Tue Jul 03 2007
jabberncc<at>aol.com
jap engine?
i have a jap engine it is small and has a 3 speed box the engine n0
is 2v/h 82187/3 can any one tell me what bike it was in and any other info
please. it could be for sale. thanks. NIGEL
The engine number appears to be 2U/H. Ed.
Fri Apr 20 2007
biffhez<at>btopenworld.com
identification
Hi ,Ive come across a JAP engine ,its a side valve,with an integral
head and barrel.I'm guessing its between 200 and 250 cc.Its has a mag platform
to the ear ,and JAP on the timing cover.Also has JAP London on drive side
.Is it from a motor cycle and if so what or a stationary unit.Regards Chris
Fife
English
Tue Feb 27 2007
debandstu
gmail
1950 Howard Rotovator w/ JAP motor
I have this rototiller and I'm wondering if someone collects, restores
or salvages parts from them. I also have the original manual that came
with it. I'm in the Seattle, WA, USA area and wonder what you might tell
me.
Seattle, WA, USA
SOLD Dec 07
JAP_Howard_Rotovator.jpg will be posted shortly.
Wed Feb 21 2007
hornetvipsapo.pt
Piston+rings for JAP 600cc industrial engine
JAP 600cc
Need help to locate source for piston assembly +rings for above engine
Lisbon
I'm fairly sure there's someone who does such
things listed in the Engine Parts directory:
http://www.dropbears.com/bikelinks/Parts/Engine_Parts/
Mon Feb 19 2007
pearsonrileyxtra.co.nz
JAP Engines
1937 engines
i have two engines at home, koz/f [serial]/s and koc/f[serial]/sm
the KOC engine has finning on the timing side of the case, where as
the KOZ engine doesn't (if has this funny protusion that runs diagonally
from the timing side.
how do i tell what i've got? also - will a J head fit (smaller bore);
i need one for the KOC engine, as its going to be raced this year.
final bit - does the pilgrim pump indicate age of the engine? or where
they used indiscriminately?
ta
NZ
Fri Jan 26 2007
Jiwilliamsn
JAP CAM
Speedway 4A/4B 500cc
I have cam for the JAP 4A/4B speedway engine with X stamped on it.
Does anyone know what this signifies?
Devon, UK
Jan 9th 2007
As you can tell I am an Indian guy all the way (10 or 12 of them)
I need a set of OHV heads to fit to some Crocker jugs I got. Whole
lower end
is Indian. I am told JAP, Matchless will work. Just what I need a new
project
RG
[See forums. Ed.]
Tue Jan 02 2007
g_skiltonhotmail
parts needed.
jap mk 2
does anyone know where I can find acylinder head for a J.A.P mk 2 motor
these are the aluminium ones, also need a rocker box. thanks Geoff.
london
Thu Dec 07 2006
brufsupaol
JAP JTOR
I am assembling two JTOR engines and need new pistons. They have 80mm
bores. Can anyone help please. Also one needs cam followers.
France
Wed Nov 29 2006
dupuis-marcwanadoo.fr
jap couvercle
je recherche un couvercle côté entrainement pompe à
huile et magnéto pour moteur jap 350 culbuté an 30
Robotrans: I seek a lid (cover?) side drive pump
oil and magneto for JAP 350 engine collapsed year 1930
(it's a timing cover he's after)
rebonjour, ci-joint les photos de la moto que je possède dont je
cherche le couvercle entrainement pompe àhuile et magnéto.
salutations de la corse marc.
...........
la marque est soit une soyer soit une
radior
pour le modèle je cherche encore!!
à bientôt marc.
Sat Nov 04 2006
renegade.geordie.johnvirgin.net
wickham trolley engine
I am looking for a book on the magneto fitted to the Wickham trolley
v engine in the 1930's, can you help me please ?
Suffolk, England
English
.........
Hi, it is a Lucas mag, fitted to a J A P twin.
J.E.HOLMES
Peter Scott Motorcycles may be able to help -
they specialise in magneto repairs:
http://www.dropbears.com/p/peterscott/
Alternatively, try the section at Bikelinks on magnetos
http://www.dropbears.com/bikelinks/Parts/Electrics/Magnetos/
Sat Oct 21 2006
luukrabberswanadoo.nl
enginge
J.A.P Diesel D270
Have jou any information of thees JAP?
holland
Tue Oct 10 2006
pethans1<at>hotmail.com
Identifying Jap engine
I have recently purchases an engine at a swapmeet here in Denmark,
I would imagine its a JAP, but no numbers or letters are found on it, the
motor is all steel, bore is 88,3 mm stroke is 115 mm. Magneto and carburetter
is british, KDV 50A4 and Amal. If anybody can tell me what it is I will
appreciate this very much.Thank you
Denmark
Fri Jul 06 2007
pethans1<at>hotmail.com
JAP Engine Denmark
Sidevalve large displacement
The question asked about the enormous sidevalve engine found in Denmark,
can not be answered to the current address( email) please write to pethans1<at>hotmail.com
with information about this engine.
Thank you very much. Peter Hansen
Wisconsin USA
Sat Oct 14 2006
bslarkbarbermuseum.org
outboard motor
J.A.P. See-Bee [?]
Any information on this motor? we want to display it in the museum
with JAP powered motorcycles
b/ham alabama USA
There is information on JAP outboard motors here:
http://www.hofmann.f9.co.uk/seabee.html
Wed Sep 20 2006
JAP aero engines
Because of my interest in Martinsyde aeroplanes
I am looking for information concerning JAP aero engines...
read
on
Thu Sep 07 2006
ken.judecgmail
new v twin JAP motor
I have heard that someone is making new JAP engines now. Is this
correct??
Fri Sep 01 2006
rbbmarkeyyahoo.co.uk
JAP single
I have a JAP single and from the info provided in the codeing link I
know it is a 600 side valve sports 1933 UCZ/W but can anyone tell me what
the W stands for. Also what gear boxes can be used with this engin any
info greatly accepted
IRELAND
Sun Aug 27 2006
hornetvipsapo.pt
JAP old industrial generator drive eng.
Need help to identify JAP industrial engine,single cyl. 86 mm bore
(now)with follw.markings on crankcase:6T59587G
Can you pls help??
Sincerely
F.Martins
Lisbon
Fri Aug 18 2006
chimpilinterra.cl
Moto JAP
Motocicleta JAP 1949
Adquiri en una desarmaduria una JAP 1949 500 cc obtener el manual u
otro atecedentes a fin de restaurarla
Chile, Curicó
Robotrans: Adquiri in one desarmaduria a JAP
1949 500 cc to obtain manual or the other atecedentes in order to recover
it
Wed Jul 26 2006
happyhamraxyahoo
HELP
350 RACING 1927
have a collection of parts trying to put together need some info and
a source of parts
main bearings are they ball journals or loose rollers and cage as other
jap have worked on
also dont have timing covers ,does anyone know if should have oil pump
as flywheels i have are oil fed any help please thanks shaun
queensland
........................
I only have the engine have enclosed some pic,s the inner timing
cover dos,nt match the outer,I prezume inner correct and racing/speedway
etc as rear mounted magneto if anybody could let me know if rollers and
cage mains(as some jap.s have worked on) or ball journals ,also if pushrods
should be enclosed or open as you can see by photos looks like tubes have
been cut but as racing may have been like this std ? Havn't the foggiest
this early /model any help /spares would be appreciated shaun
Fri Jul 21 2006
solanobtconnect
60 degree jap engines
were there any and what were they used for
london
Thu Jul 13 2006
rushman69hotmail
Lost JAP powered speedway bike
Unknown frame with JAP 500 Engine
Hi. This is a wild shot in the dark. My father used to race speedway
in the late 50's and early 60's before going going into pub management.
In the mid to late 70's he was manager of The White Hart Inn, Devonshire
Hill lane, Tottenham, London N17. When he moved from the pub in around
1975 (ish) he left his JAP powered speedway bike in the cellar of the pub
to be collected at a later date. He never did collect it and when I chased
it up a few years later the present owner said they had had a clear out
and took the old bike down to the local dump. Now I am hoping against hope
that someone rescued the bike and that someone out there someplace might
know the current whereabouts of this machine. If not to sell then to send
me pictures and get some more history of this bike and some old pictures
of it in its prime from me. Maybe someone knows something or heard a story
about such a bike being found in a scrap yard. Anyone with the slightest
inofmation please contact me at rushman69hotmail.
Many thanks.
London/New York
Mon Jun 26 2006
CLLMCLAOL
JAP
I have an old jap speedway bike I have been racing, how can you tell
what year it was made in?
VA
Mon Jun 19 2006
moragfraserhotmail
JAP engine
I have a jap engine no F/E 26328/D
I wonder if you could tell me more about it.
Many thanks
Mike Clifford.
Aberdeenshire, Scotland.
I think it's a 375cc sidevalve 1922 model with
a cast-iron flat-topped piston. Ed.
Thanks for that. Do you have any idea of the value of this engine? I have
never had it running but its not seized, It has carb, Gearbox, chains ,
gear change , kick start, although it needs a clean up and perhaps the
kick and that sort of thing would need chroming or what ever finish it
needs. Any ideas? Thanks Mike.
Try the page on Motorcycle
Valuations. Ed.
Mon May 29 2006
neelix1961hotmail.co.uk
J.A.P staionary engine
?? 100cc i think
Hi anyone got a gasket set for a amal carb
no 379/9 for my jap engine any one help
weymouth
Thu Apr 06 2006
martyn.haguevirgin.net
Jap engine
Racing V twin or 1960's speedway
I am trying to purchase either of the above to restore, and would love
to know if anyone has an engine for sale or knows where to look.
Sheffield
Mon Mar 27 2006
davidmoryshotmail.co.uk
JAP Single cylinder
Serial number IY.WMS 86239
Hi
I am trying to identify this engine a 350cc side valve (from the letters)
but its not got twin exhausts. Year I presume is either 1930 or 1950.
Is it a motorcycle engine it looks similar to any other JAP in layout
but there are no JAP identifying marks, name or otherwise apart from serial
number.
Your help would be appreciated.
Regards
David
Bretforton
Thu Feb 23 2006
rosbaldistoningram.com.au
jap speedway motor
i am in the process of pulling a jap speedway motor down...i've taken
the oil pump and cover off... do i need to pull the magneto sproket and
chain off to get the timing case off....ggreatly appreciate any help....russell
brisbane australia
The JAP directory at Bikelinks would be a good
place to search for more information
...bikelinks/Classic_Motorcycles/A_to_Z/J/JAP/
I'm sure that I've seen a site in Bikelinks which has
JAP manuals to download but it's not listed in the JAP directory.
Tue Feb 07 2006
concretesuaol
J.A.P. engine
Looking for info on J.A.P. engine F/U 9861.Such as cc. Year, use on
type of motorcycle , equipment.Thanks Toni
United States
The engine appears to be a 300cc SV 1923, and
may not have been used on a motorcycle.
Mon Feb 06 2006
t.eronengmail
J.A.P racing engine
Hi. I have one interested JAP engine. It is 600 cc ohv racing engine,
year is 1930. It is twin port head and very larges both valves, engine
number is UOR/W,....I cant remember those numbers.
Do you have any ideas, how is using this engine?
Finland
There is a page on JAP
engine numbers here, but this one is not listed.
Another similar page of JAP
engine serial numbers.
Mon Jan 23 2006
renegade.geordie.johnvirgin.net
JAP ENGINE
Hi I am after some gen on the Jap 600 side valve engine as I am about
to rebuild on, can you help me ?
Mon Dec 26 2005
demarscomics2005aol
J.A.Prestwich V-Twin engines
Do you have any photos and information on the JAP racing V-twin engine
called the Mark II buit in the late 40s I am artist and would like to have
primary and timing side photos of this model for sketching. I believe Mr.
Hagon used these in his sprint or drag racing bikes, but I can't find any
data on these particular engines.
Thu Feb 23 2006
demarscomics2000aol
J.A. Prestwich V-twin engines
Re: my first inquery on J.A.P. racing V-twins. I enclose a photo of
an engine that I believe may be a Mark-II racing V-twin model, with duel
magnetos. Perhaps someone can identify it as such...thanks.
L.A. California, USA
Wed Nov 23 2005
kingfish42cox.net
J A P Engine
What brand of motorcycle did Peter O'Toole drive at the beginning of
the movie "Lawrence of Arabia"? It had a J A P Engine. Thank you. Robert
That motorcycle was a Brough Superior, and an
account of Lawrence's association with the marque and his fatal crash may
be found here: http://www.dropbears.com/m/models/brough/
Wed Nov 02 2005
DAVID1950HOTMAIL.COM
1939 600CC SV J.A.P. ENGINE
I have a partially complete engine as above (ucz/g 6850/8) which I
am trying to get some information about.Can you advise me?What machines
were they fitted to? Where can I get a parts list or drawing as I need
to know exactly what is missing. Did it have a dynamo or did it rely on
acetylene lighting. What sort of magneto did it use?
Your help would be much appreciated.
Kind regards
David Griffiths
Fri Sep 23 2005
hailwoodhotmail
JAP engines
I have what I believe to be three JAP motorcycle engines. I want to
find out some information about them and would like the details of the
Marque specialist please.
Mon Aug 01 2005
jcc.silveirauol.com.br
Jap Engine with parallel cilinders
Has JAP Factory bild an engine with 2 cilinders parallel?
Can you send me a photo? What is the manufacturers year?
Thank you
José Carlos from Brazil
Could find no record of a JAP parallel twin.
Ed.
Tue Nov 08 2005
eddiebrantaol
Jap Motorcycle Engines
JAP made a 250cc parallel twin and a 500cc four in 1952. Look at the
1953 motorcycle show edition of "The Motor Cycle".
JAP also built a 500cc SV twin which was used
in the AJW. See article in MotorCycling Dec 9 1948. Ed.
If you have a query about JAP motorcycle engines, or wish to share your
knowledge of these classic British machines, please
contact
us!
