I found the quality of these pretty questionable. Mine wouldn't burn properly unless I put a short piece of cycle brake cable inside the vapouriser tube. Here it slows the fuel flow & adds to the heating surface area. Also, the same issues with the flaking burner plating and fuel leaking around the jet. Mine was a right pig. Maybe the jet was misaligned with the mixer tube, or something. The pump handle is cast out of rather poor alloy. The generator tube is not replaceable on it's own, it is brazed into the valve block. I think these stoves were 35 UK Pounds when I had one & they haven't gone up in price that much since. The buyer of one of these has to be aware of the lack of quality control & that one will probably need fettling to correct constructional defects. They are half the price of a Coleman 533. You must use white gas in the PT3 & PT2 also! Given the lack of spares the stoves are pretty much disposable.
I find the pump a bit hit or miss on the Motor Sich. Sometimes fuel leaks trough it and or does not seem to pump well. i.e. not raise the pressure and therefore the heat output. Any ideas?
@Evan Miller You could try taking a chunk out of the aluminium pump piston … I’ll rephrase that. Here’s the Motor Sich piston. Here’s the improved version - photo’s of a pump piston from a Shmel stove, but same design. Notice the V-shaped cut-out in the front piston face. Original O-ring (the knobbly one here) is discarded. Contributor Pau I Amor described the fix and how it works HERE.
Thanks, Have fiddled a bit with the pump so it's more effective but still have problem with fuel leaking out of the pump at the point where the shaft comes out of the hole in the lid. I have the pump handle pushed all the way in.
@Evan Miller Ah, I didn’t read your post with enough focus. You’re describing a faulty non-return valve seal. The non-return valve, from my write-up of the Motor Sich HERE. The faulty seal, circled in red. Check too the valve seat for chips, nicks, debris.
I checked the seal and yes indeed it seems to be the problem. I use white spirit (shelite) and i get the feeling the rubber they used in these does not like it.
The Motor Sich NRV gasket is sealed with a bolt. Leakage is possible if the gasket is too thin or there is not enough thread to tighten the bolt. Then you can add a metal washer, or use a thicker gasket. The pump casing at the gasket was roughly machined, and this can be also the cause of the leak. I used thin strips (5..7x30mm or ~1/4"х 1 2/4") of P400 sandpaper on the eraser of the pencil to polish the valve seat. It is advisable to change the strip to a new after every ~ 50 movements. After about half an hour, I found the result satisfactory. This "medicine" has a side effect - the sandpaper also works on the threads. But it is not significant, because the main force is directed along the axis.
Pretty happy with how it turned out with the new paint job. needed a few tweaks to get it running but think it's ready to use. ;-)
