Bloody 2-stroke engines

Experience.

Cold. Full choke. pump the primer bulb if it exists, pull and back off the choke the moment it wont stall teh thing.

Hot. Just pull. If its run out of fuel prime but don't choke.

warm. As above, but pull harder, and maybe a smidgeon of choke,. To little choke merely means it takes a long time to fire. Too much means it will flood and you will never restart it.

IME,

Cold- set throttle to start position, full choke, pump primer if fitted acouple of times. Pull cord until it sputters then dies. Choke fully off, and pull cord til it starts. Probably 1 or 2 tugs.

Hot - set throttle to start position or leave in idle position and pull cord. If no-go after 4-5 pulls, refer to "Cold" procedure.

If it's being a right c*nt, then it needs a service / new plug / carb reset etc.

Tim.

Have you been drinking them or something ?

Earplugs for all the neighbours.

Not being a user of such things, I am intrigued to know how the fuel level is maintained in carbs that have to work at any angle - even the different angles between the front and back pot of my old Ducati, used to give me headaches getting the mixture right.

A little unfair. Don't know about 2-stroke, but diesel and biofuel does:

what makes you think that fuel level IS maintained :-)

I suspect where there is a fuel chamber in the carb itself, its suction that gets the fuel into it.

Clunks are what you use to have a pickup at the tank bottom.

Not even as complicated as "additives"; petrol as distilled is a blend of hydrocarbons with different chain lengths; the shorter are more volatile. So they help starting, but evaporate. One reason why things can be a swine to start in the spring, on last year's petrol.

That entirely different: Those are compression ignition engines.

Well its easy enough to add stiff to make worn engines spring to life. But in general there is no need.

Thats what we have a spark for.

But in general cold starting has never been a petrol engine problem.

Whether they really make any

Why? its relatively harmless, lead.

Need to cosume a lot over a long period to od any real harm.

s:

Actually, on the year *before* last's, petrol. Had no problem with LAST years.

It isn't.

Carbs need a constant (and tiny) _pressure_ at the jet, so as to give a predictable flow behaviour. One easy way to achieve this is a known head and a constant level float chamber. An any-axis carb can't do this though, so they use a diaphram pressure-regulator instead, just like a gas regulator.

does:

sort of. Lacking ether, a glow plug is generally useful.

But starting additives that cost money and don't contribute to final power are a bad thing.

Better to use the glow plug.

Actually, they don't need pressure above atmosphere, since the venturi operates below atmospheric.

The simple form of model aircraft engines operate with fueel levels above and below the carb venturi and no pressurisation at all, or diaphragms or anything. Its certainly true that larger ones tap exahust pressure to pressurise the tank, but this is more about reliable running at odd aerobatic angles, than actually running at all.

One easy way to achieve this is a known

Each one can be different, just like the amount and time needed on a cold start. you just need to experiment with choke or primer if it refuses to start without, and then try and remember what worked for that particular engine.

A glow plug isn't an additive though.

There are two sorts of glow plug; those that get hot, and those that get hot and also have an independent fuel supply. This is usually methanol and comes from a separate tank (only a gallon or so). They don't burn diesel, nor do they burn any magic additive in the diesel.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember harry saying something like:

Woohoo. The Harrycarb.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Spamlet" saying something like:

Or his health if he makes a mistake handling it: lead poisoning.

#Paul