09 Agility 125 bogs/cuts out after high speed cruising for 3-5 mins - help

[LCG]

Hello,

I’m having a recurring but intermittent problem.   Before and after doing my annual jet cleaning, each time I take over a 3 mile, 55+MPH ride...  after cruising at top speed for 3-5 mins, my scoot starts bogging and cutting out until it get to about 25-30MPH. I can then reaccelerate to about 40 then it bogs / cuts out again.  I end up limping back home with a frown on my face.  This started this year and had not happened prior.

It seems to be getting starved for fuel after a while, which would point to either a vacuum lock or some other fuel system valve…???

Anyway, if you have any advice regarding troubleshooting, I’d appreciate it. I’ve only got 2200 Kilom’s.

Thanks a bunch.

[Cortez]

As you've probably figured out, it's not the jets, considering I've cleaned mine
for the first time after hiting the 18.000km mark.

Some were plugged/dirty, but the scooter was running fine.

[sparko]

could be a clogged fuel filter. check out stadiumyamaha.com for a schematic. maybe bypass it to see if the filter is your problem. good luck.

[HueJass]

Try some Seafoam fuel additive and a new spark plug..... maybe check fuel and air filter.....

[JustWantToRide]

It could also be a partially clogged gas tank vent.  Check that the vent hose isn't crushed or bent sharply. 

You can test for a tank venting problem by opening the gas cap when it is acting up.  If you hear it suck air in - then it isn't venting.  If the vent is the problem - then after opening the tank the bike will run normal for the 3-5 minutes again.

Check your fuel and air filters - but they would cause the problem all of the time instead of letting you get 3 to 5 minutes of high speed in.

[sparko]

''Check your fuel and air filters - but they would cause the problem all of the time instead of letting you get 3 to 5 minutes of high speed in.''

you are probably right here. I can only restart on a hot day by opening the fuel tank. seems like it wants to suck the gas back up into the fuel tank. And then only after I let it cool down a little. I wonder if the heat of the engine can cause problems in the fuel tank and/or fuel lines? Seems to only happen on a really hot day. Like every day for the last 3 months. 

[JustWantToRide]

If opening your tank fixes it - then the tank definately isn't venting properly.  You might also notice it happening sooner on a full tank than on a low tank...

Sometimes a tank vent hose will get soft with age - and high heat can make them even softer.  Once soft - they can vent out - but collapse when trying to draw air in to replace fuel in the tank. 

It's probably more the age of the vent tube and high air temperature than heat from the engine causing it.  But vent tubing is cheap and available in a lot of places.  I'd pull the tube off and take it with me to get a replacement.  Just make sure it is made to be used with gasoline.

I bought a closeout 09 XCiting 500 recently.  The price was heavily discounted - but I'll have to watch the rubber bits like the gas lines, vent tubes, and the tires because they are basically 3 year old parts (made in 08)...

[axy]

I bought a closeout 09 XCiting 500 recently.  The price was heavily discounted - but I'll have to watch the rubber bits like the gas lines, vent tubes, and the tires because they are basically 3 year old parts (made in 08)...

Forget it - both my Agility and People were "closeouts" and there are no issues whatsoever. My ex. Beverly 200 was also made 1.5 years before I bought it. It is simply not enough time for "rubber rot" to occur, especially considering that on sale scoots are typically stored inside. I have owned scooters that were up to 6 years old and never had to replace any of the lines. I know whereabouts of two my ex. scoots and one of my friend's. Kymco Cobra 50, another Kymco Cobra and Beverly I have mentioned. Both Cobras have 11 years, Beverly 7 - zero issues.

Tires typically can last 5-6 years before it would be adviseable to be discard them due to UV influence.  They should be stored vertically, so the fact that they are vertically on scoots helps too.

However, when I had some older cars, I have noticed that rubber hoses should be replaced after 10 or so years. For example, carburetor vacuum tubes and fuel lines. I have to mention that in my old Beverly's users manual they claim that brake lines should be replaced every 3-4 years. However, I have never heard that somebody really does that.

[Cortez]

Tires typically can last 5-6 years before it would be adviseable to be discard them due to UV influence.  They should be stored vertically, so the fact that they are vertically on scoots helps too.

Vertically, yes, but not on a scooter pressing them down against the floor.
I think they'd be in better shape stored under water then sitting on a showroom floor
on a 200kg scooter.

You might remember the Aprilia SR150 2strokes that got imported to Croatia as 5 year olds
and were sold cheap. The tires were unusable, and a lot of them needed the brake fluid
change.

[JustWantToRide]

Tires dry out and lose their elasticity by 5 or 6 years regardless of UV exposure.  The British government is suggesting a 6 year shelf life on tires whether they are still sealed in plastic or in use - and Ford Motor company is suggesting the same. 

It isn't worth it to risk them tearing or chunking or blowing out a tire - especially on a 2 wheeled vehicle.  I won't "forget it".  I'm going easy on my tires - yet they are wearing abnormally fast.  I'll be replacing them with City Grips soon.

I don't like the feel from my brakes - and I'll probably replace the fluid to see if that helps.  Rubber seals, fuel lines, vent lines, O rings - I'll check and watch them all as though my bike were a few years old - because actually it is... 

[axy]

Vertically, yes, but not on a scooter pressing them down against the floor.
I think they'd be in better shape stored under water then sitting on a showroom floor
on a 200kg scooter.

Most of the weight is on the center stand, not tires. Furthermore, there is a lot of unnecessary things and worrying here. I have yet to hear of damage to scooter/motorcycle tire because it has been stored for a few months or one year. We had a guy with apparent OCD on the forum who made 20 page log about his scoot maintenance and who changed oil every 50 miles. I would not want that people who are not experienced think that all this is really needed or that brake lines will fall apart in one year and that tires will disintegrate in two years if the scoot is left in the warehouse. One might get these impressions reading all this.

[old mod]

I'm with you there, JustWantToRide, when you get to strip an engine you find all the manufacture dates, mine were '08 '09 on a scoot i bought late'10. As for tyres in UK, we have an annual vehicle test, any cracking in the tyre walls means new tyres! I don't think any of us would recommend the oil the scoot comes with, therefore the brake fluid, gear oil etc. will not be the best. Which reminds me i must replace the brake fluid!! LOL