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350 Bultaco (pursang Twin Spark?)

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I have a 350 Bultaco from the seventies that is a definite restoration project, but I don't know just what it is. It has twin plugs which I thought would be for a quick change over mid section if the other plug fouled. But now I'm wondering if it is a moto crosser Pursang. Anyone have any thoughts on the matter, cos' I'm going to sell it and have no idea what to ask for it.

Tell us the 1st few digits of the frame and engine Numbers (after any Letter digits)and all will be revealed!

360 & 370 Fronteras and Pursangs were often twinspark. But it could be anything without knowing the model numbers.

Wayne....

Tell us the 1st few digits of the frame and engine Numbers (after any Letter digits)and all will be revealed!

360 & 370 Fronteras and Pursangs were often twinspark. But it could be anything without knowing the model numbers.

Wayne....

Both my Sherpas have twin plug heads, which work great for compression releases.

Both my Sherpas have twin plug heads, which work great for compression releases.

Dave

Most if not all Bultaco Heads have the bosses for the extra plugs or comp releases, but usually left the factory with just the vertical central plug boss machined on Sherpa's. The twin spark Pursangs etc usually used the alternative angled bosses, both plugs at about 60 degrees.

Wayne....

Dave

Most if not all Bultaco Heads have the bosses for the extra plugs or comp releases, but usually left the factory with just the vertical central plug boss machined on Sherpa's. The twin spark Pursangs etc usually used the alternative angled bosses, both plugs at about 60 degrees.

Wayne....

My M80 has 2 plugs and a compression release

sunny

I'm sure they have, but I did say "but usually left the factory" with the single plug hole. Out of many heads I have in my parts store only a few 9:1 Sherpa heads have 2 x 14mm threaded holes, and most likely they were drilled and tapped out for compression releases.

I do however have a twin spark 370 Pursang in my Bultaco collection and it is really that, ie twin spark. The motoplat coil has two ht leads and both plugs spark simultaneously.

Until we know the OP's model number we will never know what he has.

Wayne...

Sherpas were never fitted with twin spark ignition by the factory, owners had the heads drilled and tapped in the space provided as wayne says.

Quite a few models of Pursang had twin spark ignition (Motoplat) fitted as standard by the factory.

Big John

  • Author

"All will be revealed"? Liking the sound of that, here goes: JM-12500048 with a bore of 83mm

  • Author

Thanks Wayne,

The frame number is JB-19909959-A

The plot thickens?!

Well that frame is much later. Model 199A from 79-80 last 325cc trials version before the 340cc 199B.

Shame they dont match, but it's pretty common.

Wayne.....

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