1950? 500cc BSA project

GoldenMotor.com

harry76

Well-Known Member
Apr 16, 2011
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48
Brisbane, Australia
Ibedayank.....I dont believe i said id rebuild the magneto.... i may have a look though, there are steps to follow in the manual so you never know.

I also realise you need special tools and pullers, thankfully though there are very detailed pictures of these tools in my workshop manual if i need to make them myself.

In the spirit of this website im going to ATTEMPT as much as possible myself, and IF and WHEN i get stuck, ill ask for help on here and other similar sites, failing that i will take it to an expert.

I welcome all advice, but it seems your posts in this thread have been a little negative, do you want me to fail, or not even attempt it. I never said id build this bike back to front with no problems. But id like to do as much as possible MYSELF, and if i fail so be it..... but at least im giving it a go...... i looked on your profile but couldnt find ANY builds.

If you dont agree with my build and dont have constructive criticism youre free to ignore this thread.

If im wrong i apologise
 
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harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
actualy that pump is only capable of pumping the oil only so high. You will also need to learn how the line are ran and how the pickup tubes are made that go in the oil tank do it wrong and BOOM goes the motor from lack of oil
The area i talked about putting the oil tank is about the same spot/height as a standard M20 so i should be fine.

I have been studying the oil tank and its lines in the workshop manual i have.
 

rustycase

Gutter Rider
May 26, 2011
2,746
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Left coast
What a fun project, Harry!

...a few pages back there was mention of 'pitted and spalled, pinion side crank bearings'.
That was quality advice.

I have seen that a lot in old ball bearing assemblies that have been set aside under unknown circumstances, for extended periods of time.

Best to take your time and be cautious.
I would take the motor apart for inspection before making any decisions, since it has shown to be a valuable piece of iron.

...you might try putting a note up on various bulletin boards you see in your travels...
Looking for Old BSA Motorcycle Parts, and your phone number.
No telling what might turn up !
6 or 8 months down the road you might get a phone call.

Good luck
rc
 

Bicycle Motor Fun

New Member
Sep 17, 2011
89
0
0
Warren, Michigan
Happy that old BSA engine found a lover of British Iron! I have a 1954 BSA 650 Golden Flash motorcycle that I bought brand new when I was a kid--I have no plans on getting rid of it anytime soon--it is in beautiful condition. I remember seeing the BSA 500 singles on the road back then; a great engine sound from these motorcycles! Get it running! BMF
 

monark

New Member
Feb 1, 2012
87
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sweden
hello Harry! now where talking! I maybe able to help with at least some good ol advice,have a old classmate who has spend half his life to those engines and bikes(where 10 of them in the garage one time).dont speek to him so much nowdays but can give him a call next week and ask him about the numbers,i belive you and mr lucky harley have to take your builds to the next level (forumwise) not a bad thing but so you are getting the right and meaningfull advises and direction.Oceanic depth between a chinakit and your engines.
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
What a fun project, Harry!

...a few pages back there was mention of 'pitted and spalled, pinion side crank bearings'.
That was quality advice.

I have seen that a lot in old ball bearing assemblies that have been set aside under unknown circumstances, for extended periods of time.

Best to take your time and be cautious.
I would take the motor apart for inspection before making any decisions, since it has shown to be a valuable piece of iron.

...you might try putting a note up on various bulletin boards you see in your travels...
Looking for Old BSA Motorcycle Parts, and your phone number.
No telling what might turn up !
6 or 8 months down the road you might get a phone call.

Good luck
rc
Thanks Rustycase.... i posted a thread over at JockeyJournal concerning the engine and advice on it, Goldy from this site (Merkel board track copy and 1912 BSA copy) gave me that advice, and im always willing to follow Goldys advice.

Im not really sure how valuable this engine is, i have no idea? But i dont think its as "valuable a piece of iron" as everyone thinks, but id LOOOOOOVE to be proven wrong on that one.

I am looking for websites that may help, but from all accounts these engines are bulletproof and have a very large following so i think (but not 100% sure) parts for these arent a huge deal.... i guess i will see. There seems to be quite a few parts available from EBay England, quite a lot more then i could find for my 98cc Villiers engine.
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
Happy that old BSA engine found a lover of British Iron! I have a 1954 BSA 650 Golden Flash motorcycle that I bought brand new when I was a kid--I have no plans on getting rid of it anytime soon--it is in beautiful condition. I remember seeing the BSA 500 singles on the road back then; a great engine sound from these motorcycles! Get it running! BMF
Thanks BMF, im definitely becoming more of "a lover of British Iron" as i also have a number of small Villiers engines. My search for British iron started out more with a search for more affordable engines (postage from the UK to Australia is around half of the postage cost from the U.S to Aust), but i am really am growing to love them.

In fact with the amount of cheap small engines and parts (wheels, girder forks etc) i am amazed that we dont have more British members on here. I often drool all over my computer when i look at EBay England, but a lot dont wisah to ship overseas OR the postage is still a little dear :-(

Yeah dont ever sell that bike, you will regret it, and its only going up in value.... i even refuse to sell my motorized bikes, not because of their monetary value, but their sentimental value

auflg
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
hello Harry! now where talking! I maybe able to help with at least some good ol advice,have a old classmate who has spend half his life to those engines and bikes(where 10 of them in the garage one time).dont speek to him so much nowdays but can give him a call next week and ask him about the numbers,i belive you and mr lucky harley have to take your builds to the next level (forumwise) not a bad thing but so you are getting the right and meaningfull advises and direction.Oceanic depth between a chinakit and your engines.
Thanks Monark, thatd be cool, but i did track down the engine number and it suggests it is indeed a 1950 BSA M20 engine, ive since bought a manual and theres nothing to suggest otherwise.

Im not sure what you mean when you say when you suggest "me and mr lucky harley need to take your builds to the next level?". I think you mean the engine may be beyond the knowledge of our members, if so i disagree, we have a very knowledgable group collectively, and best of all MOST people are very very helpful. Thats something that is lacking in other forums.

I have however posted in a few places for advice for my engine from BSA enthusiasts. But as far as the build goes, it isnt much different to other builds that go on here, just a little beefier.

I still plan on building way more smaller motorized bikes, but i LOVE this site, i cannot go more then a few hours without checking in. Its an addiction and im right at home here among my peers.

Im just hopefully not annoying builders of smaller capacity bikes by having my bike here. If and when that happens im fine with the thread being moved, but until then i just see this as a natural progression and value you guys advice more so then other sites.
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
I should probably be getting this motor going before i worry about anything else but thats not how i roll. Im looking at parts while i study my M20 workshop manual.

This is a heavy engine, but my bike wont be much more then a motor, gearbox frame and tank so it will be a lot lighter then an M20 motorcycle, so my question is do you think a motobecane scooter hub would hold up or do i need to find motorcycle hubs?

http://www.1977mopeds.com/product/1760/Motobecane-Rear-Wheel-Hub/

These hubs are cheap enough for my build, and i really like their look but would they hold up do you guys think?

I was watching a BSA bantam hub but went for way more then i wanted to pay.
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
Since this wont be a road registered bike (at this stage) i think i can get away with rear brake only which will really help with the look. Remember this bike wont see a lot of riding.

Does anyone know of a 36 hole vintage style front hub without any brakes that is affordable.
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
I'll make my own rigid forks similar to those found on boardtrackers, that way I can make them to suit any hub I find suitable to use...... I'd heard of someone using BSA Bantam hubs on a similar project successfully.

As far as I know there are t many motorcycle wreckers around here, and last week I took a drive to town to have a look only to find they were shut :-( next time I'll call ahead and see what drum brake hubs they have to offer
 

Bicycle Motor Fun

New Member
Sep 17, 2011
89
0
0
Warren, Michigan
That BSA 500cc single engine is a thumper too; it will bounce on your frame like you could not imagine! I rode one years ago and I loved it, but my current BSA motorcycle is a 650cc twin and it is sweet! Good luck, BMF
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
I must admit i have no idea what to expect, and thats kinda exciting. Ill have to make this frame quite strong then. Like ive said my brother does rollcages for racecars, so i may get him to order me some cro-moly steel (obviously smaller OD then he would use) for strength, ill tack it and get someone else to TIG weld it as i dont think id trust my welding in this application, and just for peace of mind.
 

MEASURE TWICE

Well-Known Member
Jul 13, 2010
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CA
That BSA 500cc single engine is a thumper too; it will bounce on your frame like you could not imagine! I rode one years ago and I loved it, but my current BSA motorcycle is a 650cc twin and it is sweet! Good luck, BMF
I'm not sure motorcycles also have a class of low riders that hop, but if so then no need for pumps to bounce down the road.

I rode a Kawaski road bike 350 2 stroke tri and an Honda dirt bike 125 single. The 125 was with quite a bit more vibration and at high gear at speed it didn't really disappear.

MT
 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
I love when packages arrive and i got one today. As i mentioned i bought an Albion gearbox off EBay very cheaply (at least for here in OZ), now i just have to figure out if i can use it. Its smaller then i thought it would be, which is a good thing IF this box is strong enough for this engine, if not no biggie as ill either sell it or use it for my next 98cc Villiers or 160cc Victa builds ill do soon.

Do any of you guys know what this was for or if it would be strong enough for this engine? It looks a LOT smaller then the gearboxes usually found with an M20

Heres a size comparison with a 600ml bottle (didnt have a can of coke)









 

harry76

Well-Known Member
Apr 16, 2011
2,557
47
48
Brisbane, Australia
Thanks, I thought that might be the case. This box looked a lot bigger on EBay, I guess that's why it was cheap (by Australian standards), but like I said it'll make a nice addition linked up to one of my 98cc Villiers or 160cc Victa engines I have