gleiwitz Posted June 18, 2017 Report Share Posted June 18, 2017 (edited) Hello, I would like to ask for your help before I order a new petrol pump. Maybe I missed something during my investigation. The problem with my Sherco St 300 from end of 2013 is that the carburetor does not get fuel or gets too little. I first checked the vent of the fuel tank - one-sided valve ok, fuel hose - ok, fuel tap - ok. Just to be sure I started the engine with the unscrewed fuel tank to be sure the reason was not to vent the fuel tank I disassembled the fuel pump - cleaned - I have not seen any signs of wear or damage. I started the engine. After a while the fuel stopped flowin. I disconnected the fuel lines and fed the fuel directly to the carburetor using a syring. From disconnected fuel supply line from the pump to carburetor fuel does not flow. During engine operation in a normal situation petrol pump should pump fuel ? Do you have any ideas what else should I check? Edited June 19, 2017 by gleiwitz Quote Link to comment Share on other sites More sharing options...
gleiwitz Posted June 18, 2017 Author Report Share Posted June 18, 2017 2 minutes ago, oni nou said: Pump works by vacuum created by piston downstroke so check the vacuum pipe that goes from the carb intake rubber area to the pump itself.....if it has a cut/hole in it or is trapped/pinched somewhere then you have no vacuum and therefore no pumping will take place. Thank you very much for the reply! I checked the hose only visually. I did not dismantle it. I checked its position so nowhere is trapped / pinched. I will check tomorrow whether there are any holes or cracks. Apart from the vacuum pipe, something may be the reason for not creating a pump-induced depression? Quote Link to comment Share on other sites More sharing options...
gleiwitz Posted June 18, 2017 Author Report Share Posted June 18, 2017 3 minutes ago, oni nou said: Yes a hole or non sealing of the diaphragm in the pump itself. Thank you very much for your help. I will check it and if vacuum pipe will be ok then I will order a new pump because I am slowly losing patience 1 Quote Link to comment Share on other sites More sharing options...
tshock250 Posted June 19, 2017 Report Share Posted June 19, 2017 A friend had the same problem, I think it was a kink in the pipe when reassembling the bike. Quote Link to comment Share on other sites More sharing options...
cascao Posted June 19, 2017 Report Share Posted June 19, 2017 Or dirt blocage into fuel tank tap. Quote Link to comment Share on other sites More sharing options...
gleiwitz Posted June 19, 2017 Author Report Share Posted June 19, 2017 Thanks a lot guys for all tips. I will check the vacuum pipe carefully today. Just to be sure I will put on a new pipe and we will see Quote Link to comment Share on other sites More sharing options...
digger144 Posted June 19, 2017 Report Share Posted June 19, 2017 breather pipe from carb too long gets clogged with mud, sherco known for it, Quote Link to comment Share on other sites More sharing options...
gleiwitz Posted June 19, 2017 Author Report Share Posted June 19, 2017 Problem solved The cause of the problem was vacuum pipe. It was not visible but when I disassembled the vacuum pipe I noticed that hose/pipe clip was badly mounted at the very end which caused the hose to deform and consequently leak / catch the air. I mounted a new vacuum pipe on the lef side of carburetor where I my opinion is more space and pipe will not bends Thanks a lot for your help. Quote Link to comment Share on other sites More sharing options...
gleiwitz Posted June 22, 2017 Author Report Share Posted June 22, 2017 Today I was practice and unfortunately the pump stopped working again I got upset and ordered a new pompe. I hope this will resolve the problem definitively. Quote Link to comment Share on other sites More sharing options...
gleiwitz Posted June 24, 2017 Author Report Share Posted June 24, 2017 Heheh It will be funny when I will instal new pump and it turns out that it still does not work hehehe Quote Link to comment Share on other sites More sharing options...
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