Hard starting after scooter is warmed up

[roxyflash]

Have to crack throttle to get scooter started.Where i bought scooter from said this is a normal condition with kymco.Its a 2012 with 2700 miles on it.

[kneeslider]

Not notmal. Have your timing checked and throttle bodies cleaned.

Same thing happened to me plus other symptoms.

After the visit to the workshop. Good as new.

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[CROSSBOLT]

Not normal. Like kneeslider said PLUS possibly initializing would maybe help. 2700 miles is not even "broken in" and won't be for another 5 grand or so. I have had two of these plus all the guys and gals who have DT300I scoots can help! You may have to get your hands a little smudged!

[kneeslider]

It six years, it has done only 2700miles.  It definitely would have been sitting in storage.

Best if you can also:

1) clean out the fuel tank
2) replace with fresh fuel
3) change your spark plug
4) dump in some sort of fuel system cleaner

Try that for a start.

[Viper254]

If it starts well when it's cold but struggles when it's warm, that's also a classic sign of valve clearances needing setting.

[kymcogrampa]

My wife's Downtown (now mostly mine) has done this since new. It is hard to start whenever the outside temps are warm...not when the engine is warm. So this would negate tight valve clearance on a warm engine or dirty throttle body . I have to hold the throttle cracked open and crank until it starts. Next time it's warm out, I'll try to crank it as soon as the key is turned on before the fuel pressure builds up. I have a feeling that it is too rich and this may lean it out at first crank...I'll let you know how this turns out.

Gramps

[CROSSBOLT]

Don't forget stuck vent valves....I harp on that these days more'n initialize!

[kymcogrampa]

Don't forget stuck vent valves....I harp on that these days more'n initialize!

Crossbolt. I don't know what you've been saying on these subjects, so bear with me.

By "initialize", do you mean turning the key on until the computer has had a chance to cycle through the initial speedo and tach sweep?

With the vent valve, are you talking about the cap vent which allows inlet venting? Where would excess pressure be vented in this CARB evap system (this is what I'm suspecting is happening in the high temps). I'm guessing that the gas vapours are building up too high and causing issues? Is there a faulty vent relief valve in this gas cap or elsewhere in this fuel/evap system?

I'm going to guess that it's a given, that in order for the engine to run properly, I shouldn't skip this "initialize" stage. So maybe I'll just leave the gas cap loose to vent fumes the day before I suspect it'll get warm at next start up?

Gramps

[kneeslider]

Since you're experiencing difficult starting when it's warm, have you considered changing the CR7e plug to a CR8e instead?

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[kymcogrampa]

Since you're experiencing difficult starting when it's warm, have you considered changing the CR7e plug to a CR8e instead?

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No, I have not. How would that help me?

Rene

[CROSSBOLT]

I used to harp about initializing since it seemed to cope with surging idle speeds and stalling. Initialize sequence is key off, run-stop switch to run, throttle wide open, turn key on, ten seconds later throttle closed, key off. Why it would help with surging idle I have not a clue. What really caused that was the vent valve to the gas tank was stuck shut. The difference between fuel injected and carb is EFI surges and carbs just quit. When it finally sunk in what was happening I wanted to replace the valve which seems to be BURIED under the fuel tank. So I vented the gas cap. There is a thread with pictures.

[kymcogrampa]

I used to harp about initializing since it seemed to cope with surging idle speeds and stalling. Initialize sequence is key off, run-stop switch to run, throttle wide open, turn key on, ten seconds later throttle closed, key off. Why it would help with surging idle I have not a clue. What really caused that was the vent valve to the gas tank was stuck shut. The difference between fuel injected and carb is EFI surges and carbs just quit. When it finally sunk in what was happening I wanted to replace the valve which seems to be BURIED under the fuel tank. So I vented the gas cap. There is a thread with pictures.

Thanks for those two tips.

On my efi Yamaha C3, we call it "resetting the idle". After the battery or ecm is disconnected and then reconnected, we have to switch the key on/off quickly, 3 times in a row. I didn't know it was called "initialize".

Also thanks for pointing out the vent location. I've been drilling out vent caps since the '70s..."When in doubt, drill it out!".

We french Canadians have a saying, "We're not going to bed so stupid tonight!".

Gramps     

[roxyflash]

Hers where im at set the vavles exhaust had no clearance changed spark plug used the ngk irridium which it all ready had was in good condition .Scooter ran good was hearing exhaust popping before thats gone.Fuel is good premium also put fuel injector cleaner started fine after working on it.Let scooter sit its 95 out lots of humidity went out for a test wouldnt fire cracked throttle got it started road it 10 minutes shut scooter off bought a sandwhich went out to start it was good.Im going to vent the fuel cap, when it didnt start i could smell fuel.Was looking for the vent vavle looks like you have to remove alot of the body to get a t it unless someone knows a trick to get at it.

[CROSSBOLT]

Like I said, Roxy, the actual valve is buried somewhere below the fuel tank behind and below the radiator. Much plastic must be removed to get to it. That's why I vented my gas cap.

I like that, "When in doubt, drill it out" from Canada! Nyuk, nyuk!

[roxyflash]

Took gas cap apart drilled a number 50 hole init hard to believe theres that many parts to it lost a spring took alittle to find it but got it back together rode it 12 miles shut it off waited 10 minutes started back up ok ran it back home shut it off opened the shed started right backup.temp outside was 85 and dark out was in sun before when it didnt want to start time will tell.