Adam Posted February 12, 2022 Share Posted February 12, 2022 (edited) Hey! I've starded today my aux engine 5hp Yamaha after couple months of storage. It runs well on iddle and 1/2 throttle but at about 3/4 to max runs rough and sometimes chokes but does not stall. It looks like fuel deposit in carb so maybe jet needs to be cleaned? What do you think? Edited February 12, 2022 by Adam Quote Link to comment Share on other sites More sharing options...
daio web Posted February 12, 2022 Share Posted February 12, 2022 is there clean fuel in there mate petrol doesent last long there might be moisture in the old stuff Quote Link to comment Share on other sites More sharing options...
Adam Posted February 12, 2022 Author Share Posted February 12, 2022 Before fireing up the engine I've drained all old fuel till last drop from whole fuel system inc carb, emptied the internal tank and put a fresh petrol. Quote Link to comment Share on other sites More sharing options...
Saintly Fish Posted February 12, 2022 Share Posted February 12, 2022 3 minutes ago, Adam said: Before fireing up the engine I've drained all old fuel till last drop from whole fuel system inc carb, emptied the internal tank and put a fresh petrol. Did you add any fuel additive to clean the carb out? Quote Link to comment Share on other sites More sharing options...
Adam Posted February 12, 2022 Author Share Posted February 12, 2022 Nope mate, nothing. What would you suggest before I shall start stripping the carb out? Quote Link to comment Share on other sites More sharing options...
Saintly Fish Posted February 12, 2022 Share Posted February 12, 2022 1 hour ago, Adam said: Nope mate, nothing. What would you suggest before I shall start stripping the carb out? Others on here will know better than me on these things, but Redex for example do a fuel additive designed to clean injectors. Worth a Google? Quote Link to comment Share on other sites More sharing options...
willyhookit Posted February 13, 2022 Share Posted February 13, 2022 run carb cleaner from any motor store ( Halfords ) through it also use ( sea foam) from ebay at all times if using E10 fuel use a stabiliser i use Ethanol Shield from ( Tool Station ) Adam 1 Quote Link to comment Share on other sites More sharing options...
suzook12 Posted February 13, 2022 Share Posted February 13, 2022 If you're handy on the tools, just strip the carb and clean it. Least then you know it's clean. I will hasten to add tho, from your description, it's unlikely to be a dirty carb. Usually, when left, it's the pilot jet that gets blocked, not the main. I would be more inclined to think spark plug failing or filter blockage. If stored incorrectly, these will leak oil out which may possibly have got in filter. Once carbs have started to get fuel residue build up, I have yet to find an additive that shifts it. Far better to use an additive to stop it happening to start with JonC, Adam and MegaByte 2 1 Quote Link to comment Share on other sites More sharing options...
Adam Posted February 13, 2022 Author Share Posted February 13, 2022 4 hours ago, suzook12 said: If you're handy on the tools, just strip the carb and clean it.... Thanks for your answers guys. Yes, am OK with stripping carbs and stuff like that so will replace the sparkplug first and then will see how it behaves. It's a nice engine with super low hours and its annoying to see it not working as it should. Its been stored correctly. 2010 and up Yamahas can be stored on each side so small risk to get into a problems. Andy135 1 Quote Link to comment Share on other sites More sharing options...
JonC Posted February 13, 2022 Share Posted February 13, 2022 47 minutes ago, Adam said: Thanks for your answers guys. Yes, am OK with stripping carbs and stuff like that so will replace the sparkplug first and then will see how it behaves. It's a nice engine with super low hours and its annoying to see it not working as it should. Its been stored correctly. 2010 and up Yamahas can be stored on each side so small risk to get into a problems. I was told that all main brand small engines are the same tohatsu units rebadged, and my tohatsu clearly says what way up to stow it. Quote Link to comment Share on other sites More sharing options...
Saintly Fish Posted February 13, 2022 Share Posted February 13, 2022 28 minutes ago, JonC said: I was told that all main brand small engines are the same tohatsu units rebadged, and my tohatsu clearly says what way up to stow it. Yes mine too. Has to lay on the handle side, which my Mercury was opposite side to the handle! Quote Link to comment Share on other sites More sharing options...
Andy135 Posted February 13, 2022 Share Posted February 13, 2022 I store my little Honda 2hp upright in the corner of the store. Which reminds me, I really should dig it out and get it sold. Quote Link to comment Share on other sites More sharing options...
captin slows old outlaw Posted February 13, 2022 Share Posted February 13, 2022 what about an air leak on the carb Quote Link to comment Share on other sites More sharing options...
Adam Posted February 13, 2022 Author Share Posted February 13, 2022 (edited) 4 hours ago, JonC said: I was told that all main brand small engines are the same tohatsu units rebadged, and my tohatsu clearly says what way up to stow it. Not sure. I've seen all the small engines known brands without the cowlings and they are totally different. Blocks, heads, carbs and all bits and bobs are different. And yes, that's interesting that Yamaha can be stored in any way apart from upside down 🤪 Edited February 13, 2022 by Adam Quote Link to comment Share on other sites More sharing options...
daio web Posted February 13, 2022 Share Posted February 13, 2022 12 minutes ago, Adam said: Not sure. I've seen all the small engines known brands without the cowlings and they are totally different. Blocks, heads, carbs and all bits and bobs are different. And yes, that's interesting that Yamaha can be stored in any way apart from upside down 🤪 hiya mate the engine might not like that new fuel thats out i always put the expensive one in its only a couple of pence more good luck budd keep us updated Quote Link to comment Share on other sites More sharing options...
suzook12 Posted March 14, 2022 Share Posted March 14, 2022 @Adam How did you get on with this? Quote Link to comment Share on other sites More sharing options...
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