What have you done with your bike/s today?

[Worty]

Partial, temporary fuel blockage?

Dynamo belt may have been slipping due to it being loose (do those have teeth?).

These old bikes love to test us, may just have been one of those 'BSA moments'.

[limeyrob]

The usual suspects: fuel starvation - tank and carb gauze, plugs breaking down, mag getting hot and not sparking.  But as its a loss of power my bet is fuel too.

[RichardL]

Worty and Rob,

Agree, fuel should be considered. I was trying to imagine other causes because I’ve done the mod on the 930 carb that brings fuel to the float bowl faster. Maybe still not fast enough.

About to boroscope the cylinders to see if there’re signs of seizing. Going for the process-of-elimination approach, which sometimes leads to, “just forget about it and ride.”

Richard L.

Richard

[limeyrob]

If it was seizing up I'd expect a very weak mixture, how do the plugs look?   I've had so much trouble with the gauze in the tank (on the tap) or in the banjo filling up. They seem to be able to do that no matter how many times the tank is cleaned.

[Worty]

If it was seizing up I'd expect a very weak mixture, how do the plugs look?   I've had so much trouble with the gauze in the tank (on the tap) or in the banjo filling up. They seem to be able to do that no matter how many times the tank is cleaned.

I'm lucky Rob, the fuel leaks past the gauze and (unfortunately) the main tap pipe.  This means I've twice run out of fuel as it leaves no fuel left when switching to reserve.  The simple answer, just fill up again after around 180m or so.

[RichardL]

May need to move to a tech topic, but I’ll keep going as long as we’re in the discussion stream.

Rob,

You’re probably onto it, and may be confirming what I was thinking after removing plugs for the boroscope (which isn’t working yet). I’ve been used to seeing sooty, rich mixture, plugs. Now, they’re clean as a whistle, so, must be running much leaner.  Now I’ll be looking for melt spots in piston crowns, as well as for bore scoring. In my recent work, the main thing I did was repair the mag and re-time. Starting hot or cold has gotten much easier, with no kickback.

Richard L.


Richard L.

[berger]

my old sea dogs mate who i have known since we were 6 years old came round on his 1200 BMW . i got betsy out because he sold me betsy when we were teenagers and he loves her sound and he ended up helping me to  test to see if betsy was charging at just under 2000rpm like she used to. at 2000rpm i had a nice bit needle movement to the  plus on the ammeter but  on the last run out i noticed the ammeter not reading as it used to,  the indicators being a bit slow as well .. so as he revved betsy up to 2000rpm i only got 12.4volts and at 3000rpm 12. 8 so i might have to do some dynamo general looking at because i haven't touched it for years. ..........this is leading on to i have killed 900 robins  , as we set of i lost the left footrest because the bolt i had in it decided to break off when i stood up on the pegs, looking at where it had broke i remembered i had put that bolt in the right side footrest for years and the footrest kept dropping down when i was i kicking her up and bending the bolt which has been cold straightened a few times so that is my fault.  instead of messing and putting things right i got urma yonda out and we had a great ride out. betsy's foot rest is now mended and my bar is open *beer*thankyou for listening have a nice day

[Worty]

Big Beeza ride out tomorrow, all being well, followed by big Kwaka ride out on Wed/Thurs if my back has recovered.

[Worty]

Aye, all went to plan with a 190m ride out on the Beeza.  All went swimmingly, never missed a beat, and even had a Harley fella complimenting me on the bike whilst filling up.

Notable occurrences include whizzing round a corner to find a skittish horse all over the road.   Turned the motor off and pushed it past a good distance before firing up again.  Also, some farmer had his high pressure watering hose pointing at the road, so got a bit of a soaking - dried up quickly in the heat.  Other than that some fabulous views, on a fabulous bike, in fabulous weather - perfect.

As for the bike - the battery has now packed up (it was about 8 years old and had been knocking about the garage for ages).  Also, anyone know how to stop the feed and return pipes weeping oil at the tank end - my right hand pillion peg is now coated in oil.  I'll ask the question on how to prepare my spare gearbox outer casing to stop it leaking oil out of the speedo drive at another time.

[limeyrob]

190M  - wow!
Feed and return, Feed is just a union so check its done up.  Same for the return union, but my bet is the banjo for the rocker is not pinched up by the large nut, or its pinched up too much and deformed.  I seem to recall the fibre washers are a bit of an odd size.

[Joolstacho]

Try Dowty washers? Not dead sure but I seem to remember using them to stop my leaks around there.

[Worty]

Cheers Rob and Jools!

Union is done up nice 'n' tight, but will check the banjo and washer - the latter does look a little tired from what I can see. 

Do either of you know the size of Dowty washer I'd need offhand (for the speedo drive)?

My favourite runs are across to the Yorks Moors, where there always seems to be somewhere I've not been before.  Ended up in farmyards and allsorts on my travels in the past.  Never really interested in riding 50m then spending 3 hours chatting at some biker haunt, I like to ride.  That 190m trip cost me around 7 hours of riding, a knackered battery, £25-ish in fuel, a sore backside, a shower, four beers, aching body, and a good nights sleep - more than worth it!

Have to say it again, hats off to Bergs for the motor rebuild, even the Harley guy said it sounded sweet (mind you, anything would if you ride a Harley)

Guys, get out in this weather as much as you can, our Summers are very short and wet

[limeyrob]

If you have the later drive 65-3396 then its just the o ring 65-3397. The earlier drive 65-3390 looks like it doesn't have a groove for an o ring so if you have access to a lathe you could add one.  Or put the drive bush in with some thread sealer?

[Worty]

I reckon it must be the later drive as it's a '61 Flash.  I'll check the spare for an O-ring groove though.

I do have a split in the speedo cable plastic cover, could the oil be working its way down the inside of the cable and leaking out where the split is.  I know oil gets into the inside of the cable as it can work its way up to the speedo using the Archimedean screw effect.

[Swarfcut]

 The design is flawed, there is no seal on the rotating shaft, just a spiral groove (Archimedes Screw) to hold back the tide. Oil will work its way down into the cable, and a good sound outer cable and sealed retaining nut is the best you can hope for. Never known one that didn't drip.

 Early spindle carrier is brass, later versions are pot metal mazac, which have the O ring seal to the bore of the outer cover and a weak fixing thread to the cable nut which is a failure ready to happen with crossed threads from aftermarket crappo cables a certainty. Look closely at this thread when making an online purchase of a used item. It is fine and easily damaged.

 I've thought a breather hole may assist in stopping gearbox leaks, could  done as experiment by cutting a narrow gap in the top run of a couple of clutch lever inspection cover gaskets, rather than drilling castings.

 Swarfy