Certification - thats a question that always throws up a big debate. There is no legal requirement to get your LPG install certified, however your insurance company will probably insist that you have it certified. Tinley (or any other kit supplier) will be able to advise you further. The Tinley instructions were good and clear with instructions on how far pipes must be from moving parts, suspension etc and how often pipework needs to be p-clipped etc.
The actual reason for starting on petrol is twofold:
- The LPG vapouriser does not vaporise the gas well when its stone cold, you end up with rich running until things warm up. Not a problem as you get no bore wash etc with LPG, but it won't run so well and will waste some gas until things get heated up.
-The vapouriser gets cold. I once measured mine with an infrafred thermometer gun thing and it got to -18 degrees C or something from a stone cold start on gas. It was quickly furred over with frost!The problem with this is that the vap unit can freeze solid which does it no good and it can also freeze the coolant pipes.
In general if your antifreeze is up to scratch the second problem will not be an issue- I have only had mine freeze on me twice and then it conks out. It was -7 or something at the time. This was a couple of years ago when we had that crazy snow. I switched back to Petrol. :shock: In general I now play it safe and start on petrol if the temp outside is around freezing or below. In summer I forget all about using unleaded.
Switching between fuels with carbs can be a pain, but nothing you cant get used to. Switch off petrol when you are cruising and can safely lose a bit of speed without surprising anyone, when it hiccups lift off the throttle and switch on the gas. Reapply throttle!
When going the other way just switch on the petrol, when it bogs from being massively rich switch off the gas feed - simples!
Since I have been running EFI the switchover is seamless from LPG to Petrol, and the other way is almost seamless although not quite, I still lift off to stop any risk of a lean backfire during the switchover.
Heres a pic of my engine after it had done some 4.5 years of 65mile a day commuting - pretty clean eh?