Cold start issue of Yamaha 90 AETOL 2006 ?

[C-NUMB]

Did the winterizing of the engine this week. Before starting(or trying to) the engine had fresh fuel, and fully charged battery. All the normal procedures , air went open, priming the bulb and so on. I also put the power on in good time before( have heard that the the auto choke in this specific engine works better if electricity is switched on in good time before turning the key). It was cold outside, like +2 C, but this is not a limit for most engines.

Starter spinning with good speed, nothing... several attempt, nothing. Can smell fuel so that is moving. A few brakes between and testing also to use the idle controll, nothing.

Then made a attempt spinning the starter for a loooong time, a few promises. Another long spin then it started, very rough but started anyway. I remember last year same issue, seams to be very though engine to get going in cold.
In summer, no such issues and when warm only showing the key is enough

Did not test the red emergency switch, should have I guess. Idle was first 1300-1400 but after warming up dropped to normal so the auto choke is functional in that respect..

Is it only mine or is it typical that they are not the easiest to get running when cold outside?

[Davie]

Take the top cover off. Looking aft on the right hand side of the air box there is a red control valve. The straighter of the 2 arms on this should point to 1pm in the auto position. Turn it to the manual position and see if your engine starts using this method. There are small non return valves in the prime start system and they may be not sealing.

[C-NUMB]

The controll valve was in auto position. Will next spring when things warms up(now its snowing) also test the manual position. Need also to check the non return valves in prime start sytem, thanks for the information.

[C-NUMB]

Today about 15 degrees outside C, first test of engine this year.
Started on first try, business as usual, no problems. Litle extra smoke when burning winterizing oil but soon back to back to normal.

Also idle revs returned pretty fast to roundabout 700 rpm

I use 98E ( 5% ethanol) and that seams to be OK for 6 months storage.

But to the original problem, maybe the auto chocke is not tuned for very cold temperatures and thats why its a hard starter close to zero but ok in warmer temps.

[C-NUMB]

Today did the winter service to the engine, +1 C outside. This time tested the emergency/manual "choke", no additional work as anyway need to take the carb cover away for spraying the fogging oil. Totally different, started within seconds on first attempt.

My neighbors loves my hobby, it really took some time before engine RPM went down from 1400 to normal idle to do the fogging oil thing.....and this engine needs a loooot of oil before it will die so the amount of smoke is not small that either

For next season will fix winter tyres to the trailer so can prolong the season to beginning December, you are not allowed to have mixed tyres on braked trailer versus car.