1957 A-10 Spitfire Scrambler rebuild thread

[a10 gf]

oh boy!! I got it started this evening!!

Congratulations, some of those moments in life to remember   
& thanks for sharing your story in an entertaining & evolving thread.

[dpaddock]

Re Pollock's posting: BSA did indeed match engine and frame numbers (unless Pollock means that the same number was used for both, which is the case for unit twins from 1967 on), and where in other instances the numbers matched accidentally.

[snowbeard]

I now have it on good authority that this is a matched number, genuine 1957 Spitfire Scrambler, I can't give up my source without permission, but it's a good one! 

so, with that, I am now certain about the XX on the STD tranny being the scrambler SC.T2 gearbox.  what that actually means is new to me.  I have heard that one should change the front sprocket and maybe even the gearbox to ride it as a road vehicle.  I do have all the lighting accessories that came aftermarket for the period, so it has been intended to be a road bike to some extent...

what gear would I have stock for the scrambler, and what should I look for to "upgrade" if I wanted to go that route?

how big of a difference is it really?  I don't plan to make this my daily rider, so I could leave it as is for the sake of an accurate restoration? 

[snowbeard]

so I've been at it evenings and weekends when I can steal away.

made a clutch cable using a bicycle cable, just for now to be able to check things out.  I've gotten 'er started a few times, now, and finally cleaned out the tank. 

rebuilt the petcock last night, that was a bugger to get apart, but I got it eventually and it actually holds!! (for now, fingers crossed)

I can get it started, and found that screw that will adjust the idle, but what is that second lever adjustment on the bars, the second line into the carb?

working on the drain plate I found the screen had come loose 80% of the way round, so I used a small torch to reattach it, and added just a little solder to be sure. seems to hold pretty well.



the drain plate was held on by two bolts and a nut on a stud.  is this what was used from the factory, or was it made by someone along the way?


Shot at 2007-09-08

anyway, it runs pretty well, a good bit of vibration, sometimes it will "walk" itself on it's kickstand at the right frequency. but I don't need to sync the carbs since there's only one, is there any adjustment left or right?

 I've driven up and back the road, had it thru all four gears.  I certainly don't want to wind er out, but it seems like there's good power, no clutch slipping, altho it's hard for me to know just how much this bike should shake?  my inline 4 feels like it is like purring in comparison, but this is the first two cylinder engine I've ever had.  I guess I should assume some bump between the two, eh?

[a10 gf]

Nice to read that all is going well and ahead. The second carb cable is the choke. Oil drain: You can use bolts or studs with nuts, what's good with studs is that they stay in there for good = no damage to the crankcase threads even after years of oil changes. You might also consider SRM's sump system, has a large drain bolt with magnet.

Regards
E.

[fido]

The choke on these carbs is not really needed and a lot of people discard them as tickling is a more effective way of getting a richer mixture for cold starting.

[snowbeard]

I may just look into that sump drain too.
my stud unfortunately came out with its nut, but I can probably fix that.

yes, mine has the tickler too, so far that's all I've really used since I didn't know which way was what on the choke, I assumed it was something along those lines but I didn't know if it was an adjustment for starting or during running.  do people actually remove the slide in there, or just drop the cable and lever?

and the sprung knurled nut down on the right side of the carb, is that the idle adjustment? that's what I've been using to start it so far, tickle it a bit, turn that screw in a little bit, then kick it and it starts right up, then back out the screw to drop the idle, but I don't know how far to drop the idle, I shoot for just before it craps out.   

thanks a ton!!  I really appreciate the education!! 

[snowbeard]

well I haven't been doing very well keeping this thread updated.  I got her all running, paperwork from ITS title service, and took her down to the DMV a month or so back.  All went perfectly and I got my plates, registration, etc. Title itself came a few weeks later, but it came and now I'm all set for that end of things.

here're the pics on title day!





I drove her up to my work a couple weeks later, after a few more important things like replacing the drive chain and setting it's play. It ran great, but wasn't very fast, it was almost like riding a scooter,constantly pulling off to let others by. in fact I got passed by a school bus!  I had to run the real two lane highway for a few hundred feet and I wound her out as much as I felt safe and only hit about 50mph before I was afraid to rev any higher.  being an old bike, theres not too much surprise, but I've since learned she should be capable of much more.

went by the local restorer, he was duly impressed and helped me check my generator and regulator, which turned out to work just fine!  he commented that there was very little valve noise, either the PO had been a genius or they were too tight he said.  he was impressed with the overall running tho, so I was very happy.

then I went to ride it in the dark one evening, and in the shadows I could see the pipe on the right GLOWING red hot.  this worried me quite a bit, so I started in on the valve clearances, which were loose if anything, then moved to the contact point gap.  here i found an issue that the gap was huge, way wider then any of my guages, but only on one cam lobe!  the other lobe didn't open the contact at all! 

I realized it was the magneto armature wobbling so much that it wouldn't keep the contact braced against that lobe.  So I  went over to the drive side to see about removing the mag and found that it was even worse!! not quite enough to let the gears slip, but enough that the fibre gear was in jeopardy of being broken. 

The one thing my restorer friend said was (pointing to the mag) "whatever you do, don't ever take that off this bike"  unfortunately it now sits with the magneto removed...  good news is I found a new friend who had a few around and put one together for me.  still with the original armature and condenser, but with spark and decent bearings.  it should be enough to tide me over while getting the other rebuilt and continue to find what else needs attention!

[fido]

Good stuff  *smile*It should go a  lot better with the magneto working properly. I mentioned removing the choke. Yes you remove the whole lot, lever, cable, slide, spring, adjuster etc then blank off the unused hole in the carb lid with a bolt or a rubber grommet.

[a10 gf]

Great pictures, great work getting it rolling. Congrats.