My DT also doesent crank fast, you can always try jumpstarting while hot, you need couple second for that.. but for me that is dead end if starter behaves same during the cold and hot start.
With such an attitude then you may wonder such question before any attempt at repair? Dont you?
Main two reasons:
1: engine wear, everything changes over a period of time, when engine is "young" compression is stronger, there is more temp and pressure to better handling the bigger preingntion time....etc
2. during the distillation of oil hundreds of additives are added that can vary what can lead for engine problem that is why (at least in my coutry) sometime when I top up my tank on some gas station I have trouble with engine performance and idle speed, that counts more for my car then scooter, but you get the point.
Why you dont remove all fuel from disassembled scooter, you can use fuel pumpe to remove all present fuel, and you can add few liter of 95 fuel.
What I wrote about the octane value of fuel, I didn't get it out of my head randomy, I know few people who try that premium fuel (in my country its call 100 ocatin) what caused only starting issue...and also beacause I know how much an"impact" higher octane fuel have on ECU calculation because I do that for long time.
I get it now, thanks.
You're right again concerning the help of the fuel pump, I didn't think about it !
I remember I changed the starter on the 300 not long before storing it, so I stole it from the 300 to put it on the 350, as jump starting didn't help.
And it worked !!!! The 350 starts immediately, I went for a classic 15 min ride like I usually do for my job, then shut it off for 5 min, then on, and no problem, starts with ease, like before.
Before going to my workshop, I went to the gas station to fill a 5 liter plastic tank with 95 to bring it with me (without shutting off the engine, otherwise it may not start after that), and decided to give a try on the starter before 95 as the tank is full.
I don't think I need 95 right now in my 350 as it now starts normally (I will feed with 95 anyway from now) but I will use for the 300, as the problem was obviously not the starter !
I now have to buy a new starter for the 300, and will feed with 95, hoping it will run as expected.
I'm so happy than it runs well now, thanks to all of you for your advises.
Here is plan now, I'm going to fix (hopefully) the 300 and keep it as spare, it has no value on the market (11 years old !).
The 350 is euro3 and might be banned in a year or 2 from Brussels because emission restriction, so I'm going to sell it now as it still has a little bit of value and order the new 350 euro5.
Now I need a starter