help, please!! series 2a flame thrower!

hello.

can anybody offer some advice.
the story.....
i have a 2 1/4 petrol series 2a with a latter 5 bearing crank engine with zenith carb.
i was going down a long hill, (nothing too bad) in 3rd using engine breaking to maintain my speed. When i got to the bottom of the hill i put on some gass and it started to cough and splutter and try stall. if i let go the engine ran ok.
i pulled over and the engine ticked over fine. touch the throttle and it coughed and tried to stall.
feathering the throttle i could just manage to get it to rev but not smoothly.
eventaully (after having the stomach drop feeling when i knew id have to call the RAC) i managed to get it to rev and sustained about 3000rpm then the missfire stopped.
curred i though, must have been crap in the fuel i thought.. so drove to destiantion.
ran fine for a day
saterday i thought i should put an inline fuel filter just beofre the carb so i can see fuel and debris just beofre the carb if it happens again..
well, fitted that but took the carb off to give it a clean up.

refitted and runs fine, took out for a drive but after 1/2 mile same thing.. coughs, splutters but will tick over.
it will run with the choke out though.
managed to get back to workshop and stripped carb again, fully, rebuilt with gasket gel, cleaned mixture screw, all the channels etc. rebuilt, refitted, exactly the same.. (mixture screw all the way in, then back 2 full turns)

it seems to be running really rich, black smoke, and when reving it missfires i get flames from the exhaust.. no power, it couldn't pull the skin of a rice pudding..
adjusting the mixture screw doesnt make a slight bit of difference, either to the smoke, the sound of it or the revs.

i have noticed that the inline fuel filter i fitted doesnt seem to be filling with fuel, but enought must be getting through to keep it running..

so, what do you guys think??
it started as an intermittant problem which is now there all the time once warm.
i had a full day saterday and had to leave the old girl at the workshop and walk 2 miles home..
only problem is my only other form of transport is a motorbike and the bad weather is comming... need to get the old girl fixed asap!

any help, suggestions or just looking at this from a different angle appreciated!
Suzbug

Float bowl sticking open ?

I would first replace the mechanical fuel pump. They are only cheap to replace. Also make sure the sediment bowl is clean. Secondly check you have no leaks on your inlet manifold

Sounds like a misfire, unburnt fuel ending up in the exhaust system. Check points, condensor, coil, plugs and leads. I'd put 50p on it being the condensor.....

oxides said:

Sounds like a misfire, unburnt fuel ending up in the exhaust system. Check points, condensor, coil, plugs and leads. I'd put 50p on it being the condensor.....

Click to expand...

Reccon you're bang on there

dont know much adout landy engines but repair all my mates old outboards, pretty much all i do in the fishing season.

9 out of 10 faults are ignition related not fuel, and 9 out 10 times my mates say "just **** in the carb" (before a smart arse gets on board and asks "how often do you have to do that?" i will type it myself) . so i have to agree check points,condensor ect.

Have you checked your plugs and points?

The gap should be about 25 thou on each. Do you get a good spark at the plugs?

Have you checked the timing?

OSD

May sound silly, but check timing, it might of been marginal....

But hedge my bets on ignition system...

Pop off dizzy cap look at points and dizzy cap...

I would Replace coil, points and dizzy cap, if leads look tired, they probably are. All are cheap components and worth doing.

Oh, about year ago something similar happened, turned out my altenator was knackered...

Battery was dying on long runs, and altenator was only working at high revs.

Put your mind at rest, check voltage above 1000rpm, should be around 13.5volts at battery...

sorry for the lack or thanks and reply guys, i have only had the computer at work and it had banned this site (says its pornography!!) and couldtn get onto post a reply.

I have a mate who is hopefully comming down today to have a look at the points. I think it could be this, well, hopping it is!!

i will post up later today.
Suzbug

Hello all.
it turns out that one of the jets was blocked on the carb. Beacuse it was blocked i ddint even realise is was a jet.. daft i know.

it seems to be working okay now, with the odd cough and a splutter but im pretty sure thats becuase there was still a few tiny bits of gasket maker in the float chamber (couldnt fish them out..)

i will replace the points as a matter of course anyway.
So, the old girl runs again!

thanks for the help and advice, appreciated!
Suzbug