Gordo, I do not know if you caught the effect of the plate found on the back of the tank. It shifts the tank 1/2" further to the right. I think that is where you said you were having issues. The 1951 Daytona bikes also had the BTH TT magneto and the 8" front brake. Lloyd L

Just finished checking the piston ring gaps when fitted into the cylinder bores .... all of the ring gaps for the right side piston are .020", two compression and one oil control ring, the left side piston ring gaps are all .015" , two compression and one oil control ring. I measured each gap with the ring flush with the top gasket face, and then about one inch down into the bore.

None of the rings is marked as to orientation , i.e. Face up or Top, not sure what all of this means .... but new rings are being ordered and will be gapped ....009" to .012".

Can you tell if the current C3 is original or has been replaced ?

3 circles does sound original

Why can't you go by what John has said.

1. An interference fit on the crank means you fit a C3

2. A sliding fit means you fit a CN.

If the crank is giving you a tight sliding fit ie in between the 2 conditions then gently relieve with emery cloth to a sliding fit and go CN.

I guess it is the way the first statement was made: "the bike bottoms out on bumps". When I hear shocks are bottoming out I tend to thing one is using up the full length of travel in the shocks. If you had said the tire hits the fender I'd be thinking something different, like shock length, tire size, etc. Bottoming out shocks when racing (not tire into fender) is not a bad thing if it is not happening all the time. That means your springs will be smoothing out lots of the bumps better most of the time rather than being best for that big air landing. Of course I digress by saying that.

So the issue is really about a sick B31 engine. I would think finding out what is wrong with your engine would be the first thing to do. It might be a simple fix and the repair could be a lot easier than trying swap to another engine. I have always thought that the alternator B31 is the best of the lot. You could upgrade the alternator to a later unit and even fit electronic ignition into the points housing.

Gordo

The Triumph OIF is the easiest frame to add rearsets as it has the bolt-on engine plates. Just attach your rearset plate by the plate and engine bolts. I made a long plate to also hold the passenger pegs since with rearsets the two would be too close if left in the original location.

I used shift levers on both sides and modified the shift shaft to mount an arm on the inside to operate the transfer arm for the shifter and rear master cylinder. The plate makes for an easy mounting surface for the master.
The A65 OIF only has the foot peg and swingarm bolt hole so I think there you would have to use the rear peg mount to hold the plate in three places.

Your correct on both points Mike , A triples gearbox is basically same as a twins ; just minus the hole through the centre of the mainshaft for the clutch pushrod ..

Also my Rocket 3's "from memory" only run just under 1/2 litre of oil in the gearbox , Redline Heavy duty shockproof , Shows about 10mm on the plastic dipstick 'screwed in' .. any higher is just asking for trouble ..

Ps , if oil is coming from out the clutch case weep hole? - it can only be coming from the 'engine' side of things not the gearbox , The so called oil seal behind the clutch hub centre doesn't hold back any gearbox oil , it's basically just a dust seal really & open to the atmosphere ,

Hi,




Absent any such real thing as "ground" in DC electrics, there are only "negative" and "positive". Because negative is always 'supply' and positive is always 'return', the 'box' is always supplied by DC -ve (certainly in all the e.i. available for these old heaps), irrespective of whether the metal parts of the bike are connected to battery -ve or battery +ve (and the electronics in these e.i. 'boxes' don't work if connected between coil and battery +ve).


... simply means the metal parts of Tom's bike can be a conductor between battery -ve and the -ve of any electrical component attached.

So the "N.O.kill switch" in Tom's diagram is between battery -ve and the coil. When closed, the switch simply connects battery -ve continuously to the coil LT windings. A coil only produces an HT spark when the circuit through the LT windings is broken so, as long the switch connects battery -ve to the coil's LT windings the coil won't produce an HT spark.


While I'm guessing you mean Bransden Electronics ("Boyer" was a long-time Triumph dealer in the nearby London suburb of Bromley, Kent, although not around any more ), this also doesn't appear to make sense:-

. Coil supplied through the Black wire from the 'box', Boyer-Bransden 'boxes' for twins and singles turn off power to the coil after a few seconds if "the key [is left] on with the motor not running".

. If the 'box' is bypassed - by supplying the coil directly from battery -ve by closing the "N.O.kill switch" - it cannot be "no different from leaving the key on with the motor not running", because the 'box' cannot turn off the supply to the coil.

Depends whether it's believed turning off power to coils is important if "the key [is left] on with the motor not running". I've only once left an e.i. (a Rita) on overnight, didn't harm either battery, Rita or coils. So I've never believed the switch-off is necessary, certainly not after only a few seconds, it's certainly a pita when fault-finding and even Bransden don't include it in 'boxes' for triples.

Hth.

Regards,

Thanks, I've yet to see some that small but will keep an eye out

In the event of a loose fitting dowel I try to swedge it a little and I grind a 45 degree angle on the end that goes into the cover. Should the dowel get pumped out this will assure that the oil passage won’t get blocked. I must say I’ve never heard of something like that ever happening, but I’m sure it could.

I’m answer to your question a few posts ago, yes I can send a photo as I still have a piston on my work desk (I think) the body will be somewhere at home.

In answer to the second question, yes I can compare to a degree as I have the galled piston and a NOS one which I can strip to check, there might be minor differences because of the wear, also they are both for an A65.

Down side is you’ll have to wait at least 10 days as im about 3500 miles away from home as I type this.

Like Gavin, I like most of the products SRM sell, their pumps are really good, I use their plasma hardened valves also, chromolly pushrods and race valve springs and race cam (all but the cam is in my engine at the moment - but it’s a great item) it’s all good stuff!! But someone forgot basic engineering principles when they put a stainless piston into a stainless body..... 2 like materials will always gall - this was the problem with MK1 concentric with mazak bodies and slides.

..... now if SRM just used a stainless dome screwed onto a body and piston made of the original materials then it would be a nice piece of kit.

I too think it may be a dial face issue, possibly coupled with a speedo drive mismatch ?

The parts book for my 49 Ajay lists both 80mph and 120 mph chronometrics, as well as km/hr equivalants.
In later years there were also illuminated and non-illuminated, as well as trip and non-trip versions.
I think that gives at least 16 different varieties ?

And, I rather suspect this may be a magnetic rather than a chronometric ?
That number doesn't seem to connect with the known usual chronometrics.
And Indian sourced ones can say anything on the face, even if they are mostly all magnetic.
There are also car type ones, which are not so dissimilar and another kettle of fish.