[TravThrux]

Hello again fellas.
I tried to fire up the Thunderbolt last night and couldn't get her to go. I checked both cylinders for spark. I have a nice blue spark on the right side but the left side has a very white, bright spark - not the good blue spark we are all used to. Any idea what would be causing this? Do I have a coil getting ready to go bad? I am using the original Lucas MA12 coils. I do not have another coil to check this. Any suggestions?

Also, I do not think the Amal is getting fuel to the cylinders. I have NO experience with tweaking these old Amals so any help would be appriciated. I took it apart and cleaned all the jets and made sure everything was clean. I did not put in any new parts because, based on what I know (which is not much) everything looked good. The slide is not loose in the carb bore, needle looked good, etc....

Any help with tuning the Amal or finding out why I have that funky spark on the left side would be awesome! Thanks guys.

Trav

 

[htown16]

I'm not that familiar with BSA's but my Triumph will start up and run on one cylinder. So the side with the good spark should at least get it going. I would start chasing a fuel problem. Gas in tank, through petcocks, through any filters, gas in float bowl, float and needle valve working, gas/odor on plug? Would try to isolate spark difference. Condition of points/gap/timing, switch plug leads, switch coils.

 

[peintremondain]

maybe your carb is still blocked.old gas can obstruct everything when evaporated !
look at the t100 66 problem thread there is a good advice about carb cleaning.
ben

 

[CommandoRdster]

Yeah, you should be getting some kind of pop out of it, even if your timing is way off, or valves are too tight, or something. You're getting fuel down to the carbs, right? The petcocks aren't clogged or anything? An easy way to tell is hold down the tickler buttons till fuel drizzles out onto your fingers(No Smoking!). If no fuel runs out, none is getting to the carbs. If, after tickling, she fires, but won't start, or run for more than a few seconds, start looking for clogged jets,etc.

About the spark. Are you running points, or some kind of funky electronic ignition, or a mag?

 

[TravThrux]

I am running stock points. Now I have another problem!!! Seems I have no oil pressure. I double checked that I connected the return and feed oil lines correctly (it is almost impossible to screw up because, unlike Triumph, the oil feed line and return are different sizes). When I turn the engine over with a drill connected to the rotor nut on the engine, there is no oil return coming back to the oil tank. I can spin the motor at 600 rpm with the drill and still nothing. I even went as far as disconnecting the top end oil feed line (that comes off the return line) and NOTHING. I checked the oil pump before I put it on and spun it in some oil...seemed to work fine. This motor was taken all the way down and cases split - it is CLEAN. So I guess my next step is to take the oil pump back off and take it apart checking for worn gears etc....ARRGHHH>>>> This must be part of the fun....

 

[Mecchanica]

Prime the crankcases with a cup of oil. It can take a while for the pump to fill the cases to a level high enough to begin scavenging and then filling the return line. You can access the case through the timing hole in the front of the engine, right side.