Carb/choke problems

[Grampavan]

Van starting well but you have to keep the revs up to keep it running untill it warms up, this takes aroung a minute. That i can handle but after about 8 miles the power starts to "die" unless you rev it. You have to stop and restart engine which has to be started like starting from cold..........when successfull the van then runs well. It feels as if the engine has been flooded.
Very frustating as i cant trust going on a long journey...............any ideas peeps

[BOXY]

I'd be tempted to take out a spark plug and see what the electrode looks like. If its black & sooty that would point towards a rich mixture so it could be a faulty choke or a blocked air filter. If the plug looks ok I'd check the fuel filter in case its fuel starvation that's causing the need for giving it beans to keep it running. After that I'd break out the tacho and strobe and check the timing.

[HarryMann]

Firstly, have you told us what the engine is...?

Secondly, yes, sounds like possible flooding.

What have you checked recently and what haven't you?

Consider sticking needle valve in float chamber. Could fit these symptons!

I'd check whole choke mechanism, pre-heat, etc. But...

you don't really want to be 'guessing' your way through this and 'hoping' to find a fix... approach it systematically in an engineering fashion, checking and eliminating each element from fuel tank, filter, pump etc, right through to fuel delivery. If all OK, think ignition, but unlikely, though could eliminate that day 1 if you want, but don't jumpt o conclusions prematurely.Yup, a plug check should tell rich/weak, but so will exhaust or other ways (e.g. sound, lumpy, rhythmic > rich; flakey, hunting (slow rise & fall) > weak)