classic motorcycle forum

Interesting questions.

In 1937, Smiths 80 mph and 120 mph speedos were listed as optional extras, for all Nortons. Not shown fitted to bikes in the brochure either.
(A brakelight, and whichever model of horn you wanted were also listed as optional extras)(As was a big long list of other extras)
(A magdyno was an extra on an Inter).

In 1938, what appears to be speedos are shown (fitted) in the brochure pics - but are still listed as extras. Speedos shown look like artists impressions though, and look to be about 2".

No idea of Smiths speedo model - anyone ?
When did speedos become a required fitment ?
WD Nortons all? had 80 mph Smiths chronometrics, usually with brass bezel.

1930s Nortons don't appear to have had rev counters. The drive on the maggie drive chaincase or off the cambox is a dead giveaway, and racebikes don't seem to have them. Although one or 2 later 1930s race bikes maybe have a tacho in the pics ?

Opethiselps.

From your initial description, and also being a bit of a pessimist, it sounds like you have/had a sticky exhaust valve.

This is where the valve sticks partly open in its guide - and you lose compression - and, depending on the engine, the piston can in some cases clout the valve. Not good. This is about the only scenario where the exhaust pushrod can escape. Doesn't sound like your valve was clouted, however, we can but hope.

Don't know about the cam side of things, but the follower could just sit there once the pushrod was not returning it.

Sticky valves are usually just a gummed up valve in the guide, and a clean will cure things. Rarely will they fix themselves, better to whip the head off and investigate. If its not gummy or even dirty, you'll have to investigate further.
Doing nothing is not a good option, reliability and not being stranded being at stake.

You running petrol with ethanol ?
Your tank got a liner/sealer in it ? Still all intact ?
This does sound a little like some of the odd things folks are seeing.

Sticky valves go back into the dawn of motoring though.
Your engine burn a bit of oil ?

The stud spacing and crankcase mouth size both look much larger on the J ?
RE seem to have deliberately made such upgrades difficult.

If can fight my way to some spares, should be able to compare, be a bit later on.

And 29 had the purple tank panel, which this appears to have.
(if you can imagine purple in B&W).

Don't know.
Someones attempt to emulate BSA's (later) Star emblem ?
Looks a bit Exceslior 2 stroke tank shape - but that would require direct oiling ?

Did Malvern Star make anything along those lines ?
They had some autocycle thingies ?

Cheers.

I notice on U-Tube there is a video with a much later Kreidler with Minarelli engine - didn't watch it all to see if it actually showed the bike, but maybe there is some connection later on in Kreidler history ?
May explain an engine transplant if that is indeed what happened ?

Also notice on ebay this entry
http://cgi.ebay.co.uk/Kreidler-50cc-Minarelli-SP6-engine-classic-racer-/180617640617
Lotsa hard to find bits already provided !!
Interesting buy, bargain price.
And some keen bidding ?
Make sure you keep us updated with what you find out...

There is a Kreidler forum, in Dutch.
May get some info there, if can negotiate the language barrier ?
They probably speak english...
http://www.kreidler.nl/forum/viewtopic.php?t=23384

hth

Mmmm, this Kreidler is said to have come 2nd in the championship in 1962.
http://www.elsberg-tuning.dk/images/61kreidler12speed.jpg

Definitely a family resemblance there.
Although obviously the motor is an interesting question.

Not familiar with Thor forks at all, but it appears there are springs up inside the main fork legs, and they are acting in extension with those leading link forks.

Must have been interesting getting/setting the correct spring strength...

Hopethishelps.

P.S. Thanks for the Thor pic, speedo.
They must be thin on the ground. ?