Jan Thiel on the Bultaco GP racer:

"What can I say about Bultaco? It starts with Jamathi and Piovaticci.
In 1974 Martin (Mijwaart) and me had 2 complete bikes with engines machined from solid aluminium.
When we went to Piovaticci in october 1974 we took with us 1 complete Jamathi and a spare engine.
The second rolling chassis was sold and fitted with a Kreidler engine.

After arriving in Pesaro we went testing with the Jamathi repainted in Piovaticci colours at Misano.
Lazzarini did one lap and stopped because he could not ride the bike as it was, he was seated too
far away from the clip-ons. We had to modify the chassis to put him more forward.
When we went back to Misano after this he beat the lap record, a good start!

We then realised that with this more forward position we could also seat him a little bit lower,
so making a really very small bike. So a new chassis was made and raced in 1975. It was also the
first 50 cc with cast magnesium wheels, made by Franco Ringhini.
Later Campagnolo wheels were fitted in 1976.

At the end of 1975 Piovaticci's money was finished and he had to sell his racing department to Bultaco.
The bike arrived in Spain at the end of Januari 1976 and the first race in the Spanish championship
was mid- Februari, so the only thing we could do was to repaint this bike in Bultaco colours".
"After the 1976 season Bultaco wanted to make production racers, so casting models
were made, you can easily see the difference if you take a good look at the photo's".

"All 4 word championships were won with the Jamathi engines which were machined from solid
material, the production racers of which 4 were made had the Bultaco cast- engines".
Jan Thiel 2008