Dave,

The story you have heard of the accident in Germany is kind of true, but is a lot more complicated than probably anybody would like to understand.

The story goes that the operator over time had got into the habit of pushing the primer button whilst cranking over the machine, instead of priming first and then cranking, and this led to the metal plate which the primer contacts on the Diaphragm to bend. With the plate bent the gas pressure could force the valve off of its seat and gas could flow to the engine, with the ignition in the ON position one would guess.

The operator then one morning does his usual and bends over the engine pressing the primer and starts cranking where by he gets a nasty little surprise from the igniting of the gas stored in the cylinders and lines.

There were a number of other factors that caused the accident as I understand it and the converter problem was given as a probable contributory factor on the back of which new German regulations were introduced. The first part being that an operator should not be able to prime the system manually (i.e. they shouldn't be able to bend anything), and the second being that on an annual basis every LPG converter should be stripped and components replaced, without exception.

The Cobra is as stated an updated K with the addition of the locating holes on the casing for the primer cover and I believe the slight change of the internal components with the increase in strength of the plate that the primer button contacts. With very minor changes to the K model Impco could satisfy the German legal requirements and continue to use one converter for all markets, which is why we all have the Cobra (One type suits all).

The UK has no regulation regarding the primer cover, and the only market that needed it as a legal requirement was Germany and so as Dutch manufacturer we only supplied them on machines shipped into Germany, but I can imagine German manufacturers may have had them installed on all units.

When I was still working in the UK I found HKL Gaspower very good when it came to questions about the Impco product, so if you need more info you can find them on the web.