Page 1 of 1
amal carb advice needed
Posted: Sun Mar 03, 2013 11:55 am
by tedrevive
I have a 1977 silver century with a two jet Amal carb. It starts and runs very nicely untill the longer second jet comes into play, then I am obliged to use the choke flap to keep it running. The jets are both clear, the carb is clean and the fuel filter is in good order. Any advice? Also, on which side of the carb body should the float bowl be mounted? When I got the engine, it was on the 'tank side', the manual says 'boat side'. I looked at switching it but it seems it might foul on the transom bracket. Any advice will be greatly apriciated. All the best to you from Ted
Re: amal carb advice needed
Posted: Sun Mar 03, 2013 12:34 pm
by Horsley-Anarak
Float bowl should be on the boat side, on this engine.
Take the fuel pipe off the bottom of the carb and open the fuel tap, use a jam jar to catch the fuel.
There should be a steady stream of fuel that does not diminish. This proves you are ok from the tank to the carb.
Have you checked the filter in the bottom carb bolt?
Does the fuel bowl overflow when you tickle the little button?
H-A
Re: amal carb advice needed
Posted: Sun Mar 03, 2013 2:39 pm
by tedrevive
Hello there HA, all the fuel is flowing nicely,tap and tickle. Banjo gauze is nice and shines after a soak in salty viniger(rinsed and dried). Could it be float level? Currently there is 6mm travel on the float. Does the float bowl orientation make much difference beyond looking original? Thanks for your time, all the best from ted
Re: amal carb advice needed
Posted: Sun Mar 03, 2013 5:12 pm
by Stelios_Rjk
In the float bowl there is a needle that gets through the floater. On the needle where the floater is attached there is a gap. You could check this if it is standing there correctly. The gup is there for the wires of the floater to mount on.
Please see the pics, I may not describe it in the correct way. Where the pencil points is the gap.
About the orientation of the float bowl I don't think there is a matter. It has happened to run my engines trying both orientations and there was no difference.

Re: amal carb advice needed
Posted: Sun Mar 03, 2013 8:51 pm
by tedrevive
Say, that's a nice float. Mine's a nylon one. And lovely clear pics.
The floats located on the needle ok. That's the thing, everything looks good and seem in order, only the results are disappointing. Starvation is certainly the issue though, tickling the carb while on an open throttle lets the engine pick up. Tomorrow I'll try having the float a little above the needle notch. Thanks again for being so helpfull, it's great having other gull fans to bounce off

Re: amal carb advice needed
Posted: Sun Mar 03, 2013 10:46 pm
by chris
I would try cleaning the carb again, use compressed air to clean the jets, don't change the float setup, it will cause the motor to run erratic, I have had carbs that I thought I had cleaned and had to do it again.
Re: amal carb advice needed
Posted: Sun Mar 03, 2013 11:09 pm
by Charles uk
When they say clean the carb, they mean everything from the fueltank to the jets.
Re: amal carb advice needed
Posted: Thu Mar 07, 2013 10:47 pm
by tedrevive
Right so, I've been all through the system again and thoroughly cleaned the tank, tap fuel line, gauze filter, jets etc. But no success. It still is being starved on the long jet. I noticed the seam on the plastic float has worn a groove on the inside of the float chamber. Perhaps this is causing the float to stick up? I shall post again when I've had a go at it. Any other advice/ideas/experience of same greatly appreciated! All the best to you others in the merry seagull flotilla from ted
Re: amal carb advice needed
Posted: Thu Mar 07, 2013 10:53 pm
by Horsley-Anarak
Have you got the longest jet nearest the inlet?
Have you checked the compression, and looked for crankcase leaks?
H-A
Re: amal carb advice needed
Posted: Fri Mar 08, 2013 12:25 am
by Stelios_Rjk
What about the line that brings fuel from the float bowl to the banjo bolt? Or corrosion inside the float bowl. That could not allow the floater to move freely.
Re: amal carb advice needed
Posted: Fri Mar 08, 2013 8:32 pm
by Oyster 49
I had a very similar problem on an SD. It started well and ticked over normally, but when going down the canal on half throttle it soon ran out of steam and started to die. A quick push on the tickler sorted it out. In the end I changed the needle and float which seemed to fix it. The needle was slightly bent, and I suspect it was causing the float to stick in the up position.