[SOLVED] Agility 125 performance issues

[Downunder_Chris]

Hi All,

Really looking for some help on a problem that has been bugging me with a 2007 Kymco Agility 125.

The bike wasn't used for a period of about six months, prior to this the bike never missed a beat and I have owned it for over 10 years.

The bike was starting and idling smooth but running very rough taking off with poor acceleration. It would get up to speed eventually but very slowly, felt like a 50cc. (I also have a 2018 Kymco Agility 125 which I alternatively ride and they used to be quite similar in performance).

Given it hadn't been used for a while a neighbor and I went for a mini service with engine oil, new plug, new fuel filter, air filter seemed fine, drained the tank and new fuel. Used an engine additive / cleaner but there was no difference.

Pulled the carby and toughly cleaned, no obvious problem and overall very clean. Once the carby was back on there was still no real difference with performance. Interestingly the idle mixture screw didn't really make much difference to the idle noise / smoothness of the motor so we left that at around 2.5 turns which seems to be what the service manuals say.

Really at a loss where to go next with this - any ideas??

One thing I will add that has been in the back of my mind. Prior to the bike not being used it failed a registration check due to the head light not working. This ended up being an electrical fault which was fixed by replacing the CDI - if the CDI is faulty or the wrong one could this cause these performance issues?

Thanks, Chris

[eamartin]

The bike wasn't used for a period of about six months,



Interestingly the idle mixture screw didn't really make much difference to the idle noise / smoothness of the motor so we left that at around 2.5 turns which seems to be what the service manuals say.

If the adjustment of the idle mixture screw made no difference, you should look at the idle circuit.  Something is wrong there.  It could be that the mixture screw o-ring is misaligned at the tip of the needle and blocking the passage.  A more likely possibility is that the idle circuit fuel passage is blocked in the idle jet itself.  When you cleaned the carburetor did you remove both the main jet and the idle jet to clean them?  Could you see light through them? 

[Downunder_Chris]

Thanks for the reply... yep both jets were removed, blasted with carby cleaner and held up to the light and seen to be clear

[eamartin]

I believe that 125 has the electric enricher/choke device.  When you start it cold, the RPM's should quickly go up and stay that way for a couple minutes until the engine is warm, at which point engine slows to a regular idle.  Is this happening?

[scooterfan]

Probably a fuel supply problem. Maybe you should also do a check on the petcock valve to see whether it still works properly.

To test the petcock valve you can just disconnect the fuel hose (from the tank the carb) at the carb, and put the loose end of the hose in a container. Just leave the hose from the petcock valve as is.
Then you just press the starter button to swing the engine. When the engine is swinging, fuel should be streaming into the container - and when the engine stops cranking fuel should also stop flowing into the container.
If the fuel only dribbles into the container while the engine is cranking, he petcock valve will be faulty.
If fuel keeps on flowing into the container when the engine stops cranking, it also means the petcock valve is faulty.

[Downunder_Chris]

I believe that 125 has the electric enricher/choke device.  When you start it cold, the RPM's should quickly go up and stay that way for a couple minutes until the engine is warm, at which point engine slows to a regular idle.  Is this happening?

Thanks again for hanging in there with me eamartin. Yes, we have definitely noticed the change in revs going down so ruled that one out. We also pulled it off during carby clean and while we didn't pull it apart we confirmed internals were smoothly moving through the small holes.

[Downunder_Chris]

Probably a fuel supply problem. Maybe you should also do a check on the petcock valve to see whether it still works properly.

To test the petcock valve you can just disconnect the fuel hose (from the tank the carb) at the carb, and put the loose end of the hose in a container. Just leave the hose from the petcock valve as is.
Then you just press the starter button to swing the engine. When the engine is swinging, fuel should be streaming into the container - and when the engine stops cranking fuel should also stop flowing into the container.
If the fuel only dribbles into the container while the engine is cranking, he petcock valve will be faulty.
If fuel keeps on flowing into the container when the engine stops cranking, it also means the petcock valve is faulty.

Thanks scooterfan, we did check the fuel flow on the high size of the fuel filter and it performed as you describe. Is it worth doing at the other end to further test?

I also have another later model of this scooter so I could do the test on that one to confirm fuel flow strength is similar if there is any value in that

[scooterfan]

Thanks scooterfan, we did check the fuel flow on the high size of the fuel filter and it performed as you describe. Is it worth doing at the other end to further test?

I also have another later model of this scooter so I could do the test on that one to confirm fuel flow strength is similar if there is any value in that

I am not sure exactly how you did the flow test at the filter, but while you have a perfect opportunity to compare fuel flow with the other schooter, I think it might make sense to test flow at the other end as well.

[Downunder_Chris]

I am not sure exactly how you did the flow test at the filter, but while you have a perfect opportunity to compare fuel flow with the other schooter, I think it might make sense to test flow at the other end as well.

Hi Scooterfan, I pulled the pipe from the left side / leading in side of the filter and observed the flow... so just prior to in passing through the filter (which I ended up replacing anyway). All seemed ok but as you mention I have a good opportunity to compare flow from just prior to carby on both scooters. I'll give it a go and let you know.

[dan v.]

Poor performance can sometimes be traced to the valves being out of adjustment.  Have you checked/adjusted them?

[Downunder_Chris]

Poor performance can sometimes be traced to the valves being out of adjustment.  Have you checked/adjusted them?

Not done yet Dan.. good suggestion. I’ll add it to the list for the weekend 👍🏻

[TBR125]

I just adjusted my agility valves and it made a quite noticeable performance difference.

[Downunder_Chris]

I just adjusted my agility valves and it made a quite noticeable performance difference.

Do you know what the valve clearance is for the Agility 125?

[TBR125]

My manual had 2 different specs, .004 inches and .0012mm. I take it the .0012mm is a misprint.

.004 inches works fine.

[scooterfan]

When I did the valva clearances the first time I couldn't get hold of the correct specs, saw the clearance gaps are .12mm at some other models, so Since then I decided to stick to .12mm.   
.12 mm is just slightly bigger than .004 inch and it works perfectly well.

I think you are correct - the .0012mm is way too small and is a misprint. They probably meant  .12mm.

A .0012mm gap setting is extremely  small and would require gap checks way too often.