Problems

[jacobml9]

So I am a college student and I am using my 2018 Agility 50 to get to and from classes. I am losing power after about 1/2 throttle and it seems as if I get ideal power in about 1/4 throttle. It also seems to have trouble holding the rev as it revs up right when I pull the throttle then drops down and I can't get much more power out of it. It is hilly and cold here at times but I don't know if that is a huge factor. It has 1050 KM on it and it is garage kept. What could be wrong?

[CROSSBOLT]

Vacuum leak maybe. Main jet partially clogged, trash in float bowl. What have you checked so far?

[jacobml9]

Vacuum leak maybe. Main jet partially clogged, trash in float bowl. What have you checked so far?

I haven't checked anything. It is still under warranty so I don't want to void the warranty. I called the shop I bought it from and they said they didn't know so I figured I would ask in here so that way when I bring it back to the shop I can tell them some things to check for. Is there an easy way to check some of the things you listed?

[CROSSBOLT]

Best to listen to what they say and what they don't say to get a feel for how reliable their procedures are. This is anew bike still on warranty but something is definitely wrong with it. I started with the same model if yours has a carburetor. The thing was a pain to start when it was cold but always ran consistently once running. Where are you?

[jacobml9]

Best to listen to what they say and what they don't say to get a feel for how reliable their procedures are. This is anew bike still on warranty but something is definitely wrong with it. I started with the same model if yours has a carburetor. The thing was a pain to start when it was cold but always ran consistently once running. Where are you?

Yeah the thing is pretty hard to start in the cold but it still has trouble with keeping power once I start it. I am in the mountains of Southwest Virginia. Yeah it has a carburetor.

[CROSSBOLT]

Describe, please, the dealer you bought this from. There is a purpose to this question that is why I am being mystical...

[eamartin]

How far away is your dealer?

[JJJoseph]

Vacuum leak maybe. Main jet partially clogged, trash in float bowl. What have you checked so far?

Calm down! It's a new scooter! Try to be helpful.

[scooterfan]

I passed some comments regarding valve clearance adjusments elsewhere earlier this week, and I am a bit hessitant to pass more comments here. People might start thinking the only thing I can think of is “valve clearance problems”.

But yes - if the problem can’t be detected easily one of the things that should be checked is the valve clearance gap at your engine.
Somebody at the forum mentioned that the valve clearance gap on 50cc engines is only 0.01mm. A gap that small is almost non existant. I think the manufacturer tries to sqeek as much power possible from a 50cc engine by using such a small gap to get a higher lift at the valves.
In theory a higher lift means the engine will breathe better, and generate more engine power.

In real life a small clearance gap like that needs very special care during adjustments, because the slightest of slight mistakes can easily cause a “no gap at all” situation - which can cause strange engine behaviour, and even burnt valves in the longer term.

I’ve mentioned this before - these engines get manufactured in very large numbers each year. There is no guarrantee that all gap clearances will be correct on all engines when it come from the factory.

In short - if you can’t find the problem elsewhere, get your valve clearances checked properly.
Simply because in a O.01 setup, the slightest of slight mistakes can easily means there might be no valve clearance gap at all.

[CROSSBOLT]

You, scooterfan, harping on valves is right on the money! Too many, including me, tend to forget that as a possibility. A recent post had a bike that started well and ran well and then would run poorly when warmed. Think also would not start when up to temp. That was a zero lash problem. All was well when the owner set the valves at .004"/.1 mm. Fortunately, he did not burn an exhaust valve.

"In short - if you can’t find the problem elsewhere, get your valve clearances checked properly.
Simply because in a O.01 setup, the slightest of slight mistakes can easily means there might be no valve clearance gap at all."  Had to butt in on this! .01 mm has to be one of Kymco's errors. I saw .012 somewhere on the Like, I think. The track record for all the Kymcos we have had has been .004"/.1 mm. Anyway, this is one of the information gaps Kymco USA has ignored since I have been with them.

You harp on valves, I will harp on vent valves/venting gas caps, others can harp on batteries and pretty soon we will have a logical procedure! Light control modules, EMI filters, etc.....

[scooterfan]

You, scooterfan, harping on valves is right on the money! Too many, including me, tend to forget that as a possibility.

If it was’nt for a couple of year’s experience at work before I retired, I would never know.
At certain engines (specially diesel) it became standard practice to check valve clearances on brand new engines. Specially if the engines came from a certain part of the world....

[dan v.]

Too darn much confusing info being presented here.  Lots of conflicting info if you search the forum.  Often, cause of problem is not understanding whether the info is is inches or millimeters.

I just looked up the service manual for Agility 50 on the Googler.   Kymco service manual published valve lash is .04mm.  That is .0015in.  Have fun adjusting that! Doesn't seem right.

Google up the manual for the Super 8.  Same engine, right?  Published valve clearance is .08mm  That is .003 inch. 

Typical valve lash for the GY6 type engines is .004 inch. 

Check with your dealer.  I'm sure that they adjust them at 3-4 thousands of an inch.

[scooterfan]

I just looked up the service manual for Agility 50 on the Googler.   Kymco service manual published valve lash is .04mm.  That is .0015in.  Have fun adjusting that! Doesn't seem right.



Typical valve lash for the GY6 type engines is .004 inch. 

Check with your dealer.  I'm sure that they adjust them at 3-4 thousands of an inch.

Spot on. Adjusting clearances with a lash of even exactlly .o4 / 0015in. is no fun at all. I will be very surprized if well trained staff at the factury - who are involved in mass producition, have sufficient time to spent on close tollerances like that.

[JJJoseph]

if the problem can’t be detected easily one of the things that should be checked is the valve clearance gap at your engine.

Give the guy a break!  It's a new scooter, and he didn't say "the problem can’t be detected easily".  THAT'S NOT WHAT HE SAID. He said it doesn't seem to have much power.  There's no need to check the valve clearance (which will cost $100+ to do) on a new machine.  Calm down!  You guys will make everybody nuts (including the dealer) with all your hare-brain ideas.

[scooterfan]

Give the guy a break!  It's a new scooter, and he didn't say "the problem can’t be detected easily".  THAT'S NOT WHAT HE SAID. He said it doesn't seem to have much power.  There's no need to check the valve clearance (which will cost $100+ to do) on a new machine.  Calm down!  You guys will make everybody nuts (including the dealer) with all your hare-brain ideas.

Typical comments from somebody with no mechanical knowledge and no mechanical experience.

Just have a look at some comments by another owner who reported his experience with his NEW 200cc scooter:

1.  Valve adjustments have been made by the dealer after 200 miles on the scooter.
2. The valves clearances have been checked by the dealer at 800 miles AGAIN.

http://www.kymcoforum.com/index.php?topic=27425.0

Take note - this is a NEW scooter ! For what reason do you think the dealer bothered to “fiddle” with valve clearances at 200 miles on a new scooter ? They even checked the valve clearances AGAIN at 800 miles !

Please calm down. Are you a salesman ?