fuel consumption and carburettor

[edmundator]

('82 T25 air-cooled 2-litre)

I regularly measured my fuel consumption over the >2000 miles I have just done on my tour of Ireland. Even over a long motorway run I failed to get above 17mpg. I suspect that I my carbs may be worn and need an overhaul, but any other ideas would be appreciated.

I think it would be worth mentioning a few things. From cold, the idle speed can fail to hold and the engine will stall, or else the idle speed sometimes runs too high for a while. When the throttle is only partially opened (e.g. moving along slowly in traffic) the van often moves along jerkily. The final thing, which might be subjective, is that the van seems to struggle for power more as the journey goes on - noticeable (unless I'm imagining it) after 100 miles or more.

As I say, my thoughts are that the carbs need to be overhauled and that there is probably a fault with the auto-choke. I also mentioned in another post that I am not getting any heat from my heater vents, if this has any bearing on the matter.

Thanks, Ed

[geordie skydiver]

I had similar problems, one of the faults I found was a loose auto choke. top left of engine bay as viewed from the rear.

[toomanytoys]

Yep sounds like worn carbs, but other than that is everything all well serviced and tuned up?
Also do you run the tyres at the correct pressure? its amazing how many people never check them..... think the AA stated once that 5% under inflation could use 10% more fuel..

[edmundator]

The van was serviced not long before I bought it in May and I believe all the normal service items were replaced.

The tyres I'm not so sure about as I don't really know what the pressures are meant to be because I have 15" alloys with 195/70 tyres (are these right?). I've been running them at 38psi at the front and 50psi at the rear as this is close to what the manual suggests for the original tyres on 14" steel wheels.