Topcat47
Well-known member
The carb will need a good clean, especially the jets. Small engines like the Tohatsu 2.5 & 3.5 have very narrow jets and they can be easily clogged after a layoff. +1 for the E5, too
2stroke outboard engine.
- Thread starter Geoff A
- Start date
SaltySmudge
New member
A bigger problem for lightly used 2 strokes is the hydroscopic nature of ethanol.
I have a Yamaha 8HP 2 stroke and had problems at the end of last season of light use and the start of this, despite a full service and clean over the winter. It started fine on the choke but just died away under power or at low revs. The problem was eventually identified as the old fuel in the small (10litre) tank, probably E5 but could have been E10 as purchased in June 2021. The ethanol in the fuel is hydroscopic and had absorbed water over the 12 months I hadn't used it which separated out as a jelly like substance, blocking the slow running jet first then the main jet. The only way to get rid of the problem was another carb clean and tank flush before refilling with fresh E5 fuel. I have also fitted a Mercury water separator / filter which my outboard engineer assures me will last a season before requiring replacing. I will also make sure I disconnect the fuel line and run the engine dry before leaving it for any lengthy period.
I also have a larger bulk tank with newer E10 fuel which I still have to deal with - I will be putting additives in this to hopefully extend the shelf life - but don't have an alternative use for 2 stroke fuel.
In future I will be using E5 fuel (currently about 20p/litre extra) which I have not had problems with before but put in an additive to extend the shelf life.
I have a Yamaha 8HP 2 stroke and had problems at the end of last season of light use and the start of this, despite a full service and clean over the winter. It started fine on the choke but just died away under power or at low revs. The problem was eventually identified as the old fuel in the small (10litre) tank, probably E5 but could have been E10 as purchased in June 2021. The ethanol in the fuel is hydroscopic and had absorbed water over the 12 months I hadn't used it which separated out as a jelly like substance, blocking the slow running jet first then the main jet. The only way to get rid of the problem was another carb clean and tank flush before refilling with fresh E5 fuel. I have also fitted a Mercury water separator / filter which my outboard engineer assures me will last a season before requiring replacing. I will also make sure I disconnect the fuel line and run the engine dry before leaving it for any lengthy period.
I also have a larger bulk tank with newer E10 fuel which I still have to deal with - I will be putting additives in this to hopefully extend the shelf life - but don't have an alternative use for 2 stroke fuel.
In future I will be using E5 fuel (currently about 20p/litre extra) which I have not had problems with before but put in an additive to extend the shelf life.