BSA Lightning Bobber

My shop time comes in brief stints but today I put the ignition back together and roughly timed it. It makes sparks when I kick the engine over so it looks like the ignition is okay.

I tried firing some starter fluid in the intakes and kicking it through a few times but all I could get were some anemic coughs from the pipes. It also seemed to blow out through the carbs a couple of times. I should probably pull the valve cover off and make sure all is well in there.

The kick mechanism seems to get stuck or hung up after a few kicks. I may have to pull off the inner timing cover to check that out.


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Last night I managed to pull the valve cover and have a look. I rotated the engine through a few times just to make sure the valves were moving and all seemed well. I’ll check clearances next time I get some garage time.

There must be a problem in the kick mechanism so I’ll pull the inner timing cover at some point and have a look.

I’d really like to get this thing to light off one time before I start going nuts with it.


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Is it timed up on the wrong pot by any chance? I haven't used a Boyer system for so long I don't remember how they locate on the camshaft or if they are wasted spark. It sounds like it is only firing on overlap.
 
It’s wasted spark. This one is running a single coil and both plugs fire at once.


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Earlier today I was reading about wet sumping, a common issue with these engines apparently. When I pulled the timing plug out I got a gush of oil, probably half a quart. I know that’s a problem but would it make starting difficult?


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Yes it can make starting harder! Make sure it is only oil and not a gas/oil mixture. If it is just oil, once started everything should return to normal once the pump starts circulating. Make sure you have enough oil in the tank before starting. If oil/gas mixture drain the oil.
 
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After I check valve clearance I’ll drain the sump for real. Catch it, check it and if it’s good pour it back in the tank. I’ll do all that before I try starting it again


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Little by little. Figured out I can’t mess with valve lash without Whitworth tools.

Managed to pull the sump plate and let the oil drain. Between what gushed out when I pulled the timing locator plug and the sump plate there was probably a quart of oil in there. That was all I got done before the baby got fussy. Maybe I can get a little more done tomorrow.


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It's A bit of work getting out to do stuff with a little one in the house. Then they get big and misplace stuff, sockets, screwdrivers, valve retainers, pistons LOL...fun times though..
 
Put things back together and tried giving it a few kicks. Didn't have the fuel tank mounted so I was hoping to fire off whatever fuel is in the float bowls and I squirted in a little ether just for good measure. It seems a little easier to kick over without all that oil in there but I didn't get anything promising. On some kicks I get a little puff back through the carburetor which seems odd to me.

When trying to install the new kickstart lever I bought a few weeks ago I broke the damn tapered pin that holds it on the kick shaft. I had a steel punch stuck in it just for testing purposes. Well today I kicked it and broke the punch so I'll wait for the new kicker pin to arrive before I do much more. Got a set of Whitworth tools on the way too.
 
IIRC, that pin, which is called a cotter pin in the UK, is the same soft piece of steel as those used in bicycle cranks back in the day. If your local bike shop still has p[arts for old bikes, they may have a pin for you.

Google bicycle crank cotter pin and you will see pages of them.
 
IIRC, that pin, which is called a cotter pin in the UK, is the same soft piece of steel as those used in bicycle cranks back in the day. If your local bike shop still has p[arts for old bikes, they may have a pin for you.

Google bicycle crank cotter pin and you will see pages of them.

I read that on a couple of forums. I went ahead and ordered a couple from Lowbrow. I’m tempted to check with the local bike shops anyways. I was unable to install the one that came with the kick pedal. It would not smoothly go through the pedal on or off the shaft. I damaged and broke it trying.


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If I remember correctly the pin is flat on one side. I'm relying on the 50 year memory of my A65L chopper. I had to have one made in 1974, fortunately I had a friend whose father was an outstanding machinist. The ex Triumph/BSA dealers were either hoarding all the parts or were so mad at the company that they wouldn't sell them. It is easier to get parts for a BSA now than it was in the 70s. My new bride and I drove 100 miles one way to get a replacement rear axle for the beast. The previous owner couldn't figure out how to get it apart and had cut the head off with a hacksaw.
 
Correct, and they must be fitted only in one direction so the tend to push in tighter, so nut goes to the front.

Pretty sure that the BSA Rocket 111 I had in 1977 had that style pin in it....
 
Shouldn’t it just slide in the kick pedal when it’s not mounted though? This one would slide in and out easily even with the lever off the bike.

Is it always very difficult to slide the kick lever on and off the shaft? Seems like it should just slide on and off but it’s very difficult.


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Correct. The pin diameter should match the cross hole in the kickstart lever, so it can be pushed all the way through if it's not on the shaft.

The starter lever bore should match the diameter of the shaft and should not be too hard to slide on or off but should not be loose and sloppy.

If it's really hard to fit, check that it is the correct size but look for burrs on the shaft end and at the ramp sides as well as checking the lever arm.

It is very possible that it might have been hammered oval or the end rounded off.
 
I noticed that whenever I kicked the engine through I would feel a slight puff of air coming back through the carburetor so I started to wonder if the cam timing was off. I wanted to get a look at the kickstart quadrant shaft anyways so I decided to remove the inner timing cover. I turned the engine through a bunch of times and never got the timing marks to line up so I removed the idler gear and line things up. I think I’ve got it pretty much the way the picture in the manual shows it.

How did it get this way to begin with? We may never know. Fairly certain that the PO told a few lies when he said that he had been riding it though. I don’t see any evidence that it jumped time. More to follow when I get time.
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I suspect the previous owner had been messing around in there because the bike wasn't running.
 
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