Hi does any one have an idea of the top speed standard of these 70s  250cc machines. originally a flat tracker and I think used in go karts  Thanks stu

Hi, one of the locals ran a Pursang in out sprints some years ago, max speed was about 75. The limiting factor always is the size of gearbox sprocket.  13 T with a 520 chain. However, you can go bigger if the kickstart shaft is removed. Likewise the rear hub, not much you can do to fit a smaller rear sprocket, the best thing to do there is to find a hub from something else. What exactly is your intended plan ? A few more details would help, then I am sure a fellow reader of these posts may have done what what you are setting out to do. Hope this helps.......

 

Thanks for that very good info I'm toying with idea for a cafe road racer project I've been thinking of doing for some time now .A metralla engine would be first choice but rarity and price of engines is a no go. so looking for an alternative bultco engine that could be geared for good road use .

I have been looking at this for a while as i have been considering building a track bike with a 370 motor i have in pieces. Still trying to decide whether to commit though. I had come to the same conclusion regarding the rear hub and losing the kickstart but the sprocket would still be very close to the ignition rotor cover. I notice AJR in Spain have larger front sprockets for the TSS. Would you know if these have the same 25mm splines?

 Is an Astro easier to find than a Metralla?

 As I recall, when Pursangs first switched to wrong side shift, the rear brake was moved to the right (or wrong) side of the wheel with a two piece rear hub. I would think you might be able to fit a smaller sprocket to that hub.

13 hours ago, petorius said:

I have been looking at this for a while as i have been considering building a track bike with a 370 motor i have in pieces. Still trying to decide whether to commit though. I had come to the same conclusion regarding the rear hub and losing the kickstart but the sprocket would still be very close to the ignition rotor cover. I notice AJR in Spain have larger front sprockets for the TSS. Would you know if these have the same 25mm splines?

I own an original TSS and unfortunately can confirm it has a 30mm spline. Although I'm sure a company like Talon could manufacture one to your dimensions.

The other thing to maybe consider would be clutch, The TSS has a gear driven primary with a vastly heavier duty clutch over the chain driven Pursangs or Metrallas and even this struggles and slips with tall gearing  

Thanks for the info WT, is that a Model 6?

35 minutes ago, petorius said:

Thanks for the info WT, is that a Model 6?

No its a Mod29 1969 350 although the cases in the picture are actually from a El Bandido Mod18 built into spare engine with TSS internals way back when.

The El Bandido & TSS both shared the same cases and gear driven primary although that's where the similarities end.

For the sake of originality I tend to race it with the 'Frankenstein' engine and keep the original on the shelf.

   

Can you share more photos of your TSS plse? Do you take it to circuits these days? I race a Metralla MkII Kit América in Belgium and - some day - owning a genuine TSS would be eh...fantastic. Do all TSS's have a 30mm spline? Best to all.