69 BSA bobber project...or...the cure for wintertime madness!

[Bloodweiser]

The 500 was a single carb, right?

Does the intake manifold match up to the 650 head too? I'm thinking of picking up a manifold so I can run a single carb for awhile.....

[Airhead Wrangler]

Originally Posted by crazydrummerdude

Aw, come on... That's just "surface rust"

[YZman]

Originally Posted by Bloodweiser

The 500 was a single carb, right?

Does the intake manifold match up to the 650 head too? I'm thinking of picking up a manifold so I can run a single carb for awhile.....

Not that I know of. Im pretty sure they are 2 diff heads between single and dual carb.

But

I know of someone (me) that has a recently polished 626 Amal carb that will be for sale if you happen to know of someone (you) that would like it.

Here is a pict of my 500 and 650 head. They are diff designs.

500 head with intake (you have to squint a little)



And the new 650

[Rathlindri]

Not being a BSA expert I may well be wrong but if similar to unit Triumphs (650's/750's) the single carb head has parallel intake ports while the twin carb has "splayed" ports? You're doing some great work and providing lots of us with interest and entertainment...cheers!

[BrianK]

That sounds right. The Lightnings had twin carbs, the Thunderbolts one (and no tach - and that's about the sum of the differences). The heads on the two bikes do look different to me, as Rathlindri points out.

[YZman]

Oh and speaking of carbs. Anyone know anything about these??

http://www.rockypointcycle.com/Merch...tegory_Code=T5



Keihan 30mm D-Slide. Looks like a good carb for this bike. And the cost is about right also.

I saw a Mikuni round slide kit for around $400 (ouch)

[BrianK]

Not familiar with that particular carb, but I have Keihin "FCR" flatslides on a couple of bikes (including 35mm ones on a 73 Norton that's probably fairly similar, spec-wise, to a 650 BSA) and they are AWESOME carbs. Beware, they come jetted ridiculously rich (even if set up, as mine were, by experts in the particular marques for which they are intended).

The big diff is that the FCRs are also ridiculously expensive. These are much more reasonable. I'd go for it.

Edit - I was looking at the Mikuni pic. That round venturi looks like my FCRs. Not sure what a "D-slide" carb is - I assume one side of the slide is flattened. $400 for a great set of carbs ain't bad. Understood, $260 is better....

BTW, if like the FCRs the Mikunis dispense with a choke in favor of an accelerator pump, I must say I've found that a much better system for starting, not to mention acceleration. So the additional upfront expense MAY be worth it.

Not my money. I'll shut up now....

[jeep44]

I'd say stick with the Amals. Simple,easy to tune,plentiful parts for them. If your slides are worn, send the slide and carb body to Lund Machining,and they will resleeve the slide and bore the carb body for a nominal sum. All my previous Triumphs and BSAs were one-kick starters with them.

[Bloodweiser]

Thanks for the info on the heads.It would've been nice to just need to score 1 carb and pick up another when I got some more cash together, but oh well.


Amals are around $300 for a brand new set.

You should scope out this site yz http://piled-arms.com/pub.html
Good tech essays for these things. There's one on amal vs. mikuni and another on another JRC carbs.

[YZman]

Ok...I got that outta my system




Now to get back to the BSA

[YZman]

So I got a bit done today. Still in the tear down and clean mode but making progress.

1st up was get the clutch out. The clutch plates were really in there. But slowly one by one they gave up there hold and came out followed by the inner and outter hub and a pile of tiny little bearings. Sweet!









Looked a little icky but Im pretty sure it will clean up just fine.


Next up is the alternator/generator. Came out pretty easy. Once I got it off I realized that there was a flywheel in there. The flywheel is...pretty



So that side is tore down about as far as I can go.


Onto the other side.

I start pulling screws out and gently tapping on the side cover with a rubber mallet thinking of Blood the whole time and realizing that it dont want to come off. Ahhh the advance thingy behind the points has to come off. Done......still dont want to come off....All right time to read the manual...Manual says to remove the 11 screws and it will come right off. Count up my screws....9...hmmmmm Im missing something. Ah ha..there they are at the bottom of the cover. Pulled them out and it came right off.

Yummy






Oh also got the pistons off the rods. Check out this sexy shot



Once I got the clutch and chain off the crank spins like butter. Super smooth. Well smooth considering the toxic black goo that still resides in the cases. Gonna have to drain that crap out into something before I split the cases.

Well thats it for now. Maybe Ill get out there tomorrow again for a bit....Or maybe Ill just sleep all day instead.

[YZman]

Progress report...

Not a lot to report. I spent my lunch hours this week cleaning up the clutch basket and inner hub. The rubber cushons amazingly were in good shape and will be re-used. I cant believe how heavy that clutch assembly is on this bike. Its simply amazing. Heck just the inner hub has gotta weigh 3 lbs.

So anyways they cleaned up just fine with a wire wheel and a lot of digging with a scraper to remove the remaining crust. I shoulda got a picture today but forgott.

I must admit I mostly worked on my sons YZ85 today, trying to get it ready foor spring. Changed 2 tires, the clutch basket, rear caliper, re-jetted the carb, and pulled the forks in prep for new seals and some re-valving.

But I did get a little done on the BSA. I removed the oil pump





And Im stuck again. And this is the bastard



Its the center part of the clutch. I assume this is why I bought that clutch puller tool.



Ive used pullers before. But this bugger just dont want to come off. I threaded the puller in. Tightened the center bolt waaaay up. Tappped on it with a hammer...tightened some more...wacked some more....Hit the puller with an electric impact wrench.... Nothing. Its on there but good. Am I missing something? Im thinking my next step is heat it up with the Acetaline tortch and see if that gets it off.

So seeing as I was stuck I tried to get a little organized. My pile of shiny parts is growing nicely...me likes.




Which one of these things is not like the other




Thats it for this weekend

[YZman]

DAAAHHHHH



Fridge bought the farm today......New fridge set me back $650 smackers...


Thats $650 in BSA parts that were just ripped outta my hands. Man that really stings.


All I got to say is that bloody fridge better keep my barley pops damn cold

[SOS]

YZman,

I was watching Btrittown last night (by Scott Di Lalla and Zack Coffman) and thought of your gear issue. I think they featured the same problem on a '71 Triumph. It looked identical. Anyway, it is worth a beer and a quiet evening to watch it. Especially if your funds are running dry for a little while.

[YZman]

Well I can still continue tearing the motor down and polishing parts up. That dont cost much.


And speaking of motors....That oil pump is suspect. Should the pump spin freely in both directions? cause it dont. It will only spin freely one way and stops dead in the other. Unfortunately the direction it seems to stop spinning apears to be the direction that the motor spins it.

Given the amount of gorp I have been picking outta this motor it wouldn't suprise me if something is in the pump. It looks like I am tearing the pump apart to see whats up in there. Dosn't look like there is much in there to get me in trouble.