1951 ES2 frustration

Sounds like a sticky inlet valve.You could try adding some two stroke oil to the fuel.Or Redex.

Sounds typical of a worn carb to me. I've sent a couple of carbs to Martin Bratby before, including the one off my ES2 and have been very impressed with the results.

It's worth checking for a sticky valves before paying out for work on the carb though.

Sticky valve sounds a good possibility given the history & symptoms you describe. If the new fuel contains ethanol, this will dissolve the varnish residue left behind in the tank from the old stale petrol, which then collects on the inlet valve stem, turns into a sticky goo, gets dragged up into the valve guide & restricts the free movement of the valve. The fact that it ran ok for a while, and then got progressively worse would lead me to check this first. Iâve seen this happen a few times since the introduction of ethanol, both on bikes & cars that have been re-commissioned after standing idle for few years.

Regards, Tim

My 1947 model 18 did exactly the same and it drove me mad. In the end it was a worn carb slide. As it went up and down you could never get the mixture right as it never settled in the same place twice and spat and coughed. I sent mine direct to AMAL and they rebuilt it for £67,,,They were great, well worth doing as it may of scored due to grit etc after being left dry so long.

Previously derek_hackett wrote:

Good afternoon,

My original condition 1951 ES2 was unused for two years after moving house. The fuel tank was drained. Resurrection and big clean up with new oil etc and carb cleanup carried out. On starting after a short period of running okay it began to spit back through the carb and gradually got worse. I tried the usual stuff, timing, new points, pilot jet cleaned etc. new plug and finally sent the magneto away for rewinding as I thought that the internal capacitor had gone wonky, as advised by a friend. First class job on rewind but on starting it again began to spit back. Could it be that the throttle slide is worn and need resleeving? or should I be looking in the more obvious places. Timing proved problematic as the shaft turned on several occasion when i tapped it onto the taper. Is there any way of jamming the engine while I tighten it? I am stuck and will appreciate any expert advice or tips from those who have experienced similar problems.

hi when seting the timing chalk the taper on the mag that will grip when you tap it on .I hope this passes the sencer my advice is based on experiance.dick richardson