BSA B40 SS90 road test with 19t gearbox sprocket instead of 17t but electrical issues evident. 

It is a good looking bike. And now also properly geared too.

The old "Beefo" seems to handle the taller gearing with no troubles at all, still thunders up hills. I had a B40 once, felt like completely different animal to a C15, amazing what a difference 100cc makes at that size. I think 350cc is a "sweet spot" for motorcycle engine capacity, enough power and torque and minimal weight.

A great upgrade paul good stuff, with the price of watered down E10 these days, that extra stride length will be welcome 👍👍👍

Half way trough.there was strange noise.maby just mike.but it sounded like if the chain was rubin over sheet metal.bike sounded real good an deep tone in first part video

I had a "rouge " spark on my Enfield many years ago, turned out to be a poor connection at the battery fuse connection. This going "OC" intermittently caused the coil to fire. I'm surprised the engine didn't break as it fired way before TDC and almost stopped the engine dead at around 50MPH!

I quite fancy one of those myself.

Yes, you can hear the miss on the video. Hate intermittent faults, they can be a pain.

That is about the only unit single BSA I never owned. Had C-15,a load of B-25 and 441's and 4-5 B50's ,even a lone C-11 plunger frame. I'm pushing 200lbs and the B-25's were suprising powerful if kept wound up.

I think you hit it spot on with sprocket change Paul - are points shorting or something bit odf a intermittent misfire?

Once the very "Apex of Dowdy" in her heyday, even with that fancy (optional?) chromed tank, isn’t it something just how sexily lithe and desirable that little Beeza single seems now? She's like a remarkably fit little "cougar" in fishnets, that one. It seems you've done her the power of good upping her to that 19 tooth sprocket. She seems to course along quite happily now with a bit more gumption for modern roadways. I once had a fairly similar Victor 441 Special that was all but useless over 50 due to its low gearing--perhaps even lower than that one's for off-road tractibility--which might have benefitted mightily from a similar sprocket swap. Yet during your ride I also sensed just a bit of intermittent "halting" at load...similar to what one might get with a fouling plug or something loose or a poor connection in the the ignition system, like a ratty low tension lead to the coil or something. And like the earlier commenter Gerald, my "spidey sense" also hears a bit of buzzy-rattling that would have me looking for a loose or missing fastener somewhere: head steady? something bolted to the frame? A loose mudguard stay? Something's fussing.

Beautiful bike and ride. Thanks!

That's going to be a nice bike shortly..

Engine sounds less laboured than under your 17t gearbox sprocket link and coping easily heavy load. Best way to check I suppose is to measure rpm (does it have a tacho?) and plot the road speed for difeerent types of road conditions of mph/rpm which would give a fair comparison. The electrical issues are a bit more obscure but obver to you maestro!

Pity about the electrical gremlin spoiling things as your gearing selection works well. Thank you.

The BSA singles were great motorcycles I love the 250 single because they are so easy to start with like half a k i c k. My 250 C15 will run at 60 miles an hour all day with two up in August in Florida, with plenty of throttle left over. It's supposed to have a top speed around 90 miles an hour but I have bigger motorcycles if I want to go that fast. My 250 Enduro bike can keep up with Japanese water cooled wonders because you can't go 100 miles an hour on a dirt Trail unless you want to wrap yourself around a tree, and I have seen that too. Today's bikers are so lame they cannot do what would be considered regular everyday maintenance on an old bike they are barely capable of fueling up their own motorcycles without setting themselves on fire what that makes for great videos to laugh at

Greetings Paul Love your vids question for you My B 40 Clutch is dragging how would I correct this ?

Sounds good Paul, looks like you've cracked it. My old Dad, God rest his soul, wouldn't have a single unless it had a roller bearing big end, and by the time these bikes came out they were all plain bearings if I'm not mistaken. He maintained plain bearings were no good on a single, his comments were born out (at the time) by lots of big end failures on C15s, Tiger Cubs etc.Of course it could have been poor maintenance, etc. What's your view Paul?

Iam going to be installing a 19 tooth on my B 40 never liked the gearing , I went up 1 tooth on my A65 love the difference . How many ling chain did you use if know off hand ? Thanks Paul

Lovely balanced look to the bike. It’s a shame you can’t buy a modern equivalent. I have a 2022 RE classic 350 but it’s probably no faster and I’m sure much heavier and encumbered with ABS, Cats, electric start ……. All unnecessary for a 20hp 350 single 😊. b40 with a balance shaft in the engine would prob be a better much lighter bike.

Out of interest, how would you rate the B40 against the B44?