My S8 died on me

[blackhawkfan]

I took my scooter out on my third ride of the season today.  I had no problems with it before and the previous rides put about 17 miles on it.  Even starting it for the first time, it took a few hits on the starter button but it did start.

It started right up today and I went for about two miles.  I was on a quiet section of road and decided to give it full throttle.  I guess that's what did it because I heard some pops, I think from the exhaust, and it lost power and cruised to a stop.  I also remember smelling something like smoke, but don't know if that was me.  I tried to start it back up but nothing happened.

What happened and how can I fix it?  When I stored it, I filled up the gas tank and put in some stabil.  I did not put in new gas when I took it out of storage.  Please advise what I should do.  Thanks

[Chris0381]

Check for spark -

Check Compression - Compression gauge

Check fuel supply and if 2t oil is pumping - not sure myself on this

Check proper air supply - air filter, airbox etc

Now I haven't had to trouble shoot mine, so I dont really know all there is to trouble shoot your problem.

Edit you profile and list all mods little or big that you may have done to the scooter or no one can really help you in an efficient manner. We dont know if you have a 4t with valve issues or a 2t with carb tuning issues.

Do a bit of youtube searching on the 4 areas I mentioned above.

[blackhawkfan]

My S8 is a four stroke with no modifications.  I will check on youtube for the things you mention.

[vespbretta]

What do you  e x a c t e l y  mean by "I tried to start it back up, but nothing happend"
Nothing is an absolute phrasing... Did the starter turn over? Did the Engine turn over? Or was all dead? Can you hear a clicking noise of the starter relais?
Is there a spark on the sparkplug while turning over the engine?
Is enough Engine Oil in the Engine? Is too much Engine Oil in the Engine? Did you check the correct Oil Level?
Is the petcockvalve working properly? Is there fuel in the carburator? Are the vacuum lines to the petcockvalves in perfect condition?
Is the battery Voltage still ok? Did you measure it? Does the Headlight come on, when key on?
Did you flip the killswitch a few times from on to off and back to on again? Sometimes they have a strange behaviour.

Your mentioning the smell and smoke, might lead us to another common issue with these Kymco Carburator Scooters.
Sometimes the electrical driven Cold Start Valve (Choke Valve) on the Carburator gets stuck retracted. This causes the following issues:

While the scooter starts normal and runs normal when cold, it dies every time in idle when hot. Why? Because the scooter then runs way too rich. This could also be seen at a too dark (black)/wet  spark plug tip. Should be light brown normally.
Also the wiring from and to this Cold Start Valve might have a break/Short circuit somewhere to cause these kind of issues.

[blackhawkfan]

When I tried to start it without giving it any throttle it would just click.  When I gave it some throttle it would kind of put put put but the engine would not run.  I checked out YouTube for the spark and compression issues mentioned above, and both require removing the spark plug which I have not yet been able to do since it is in there so tightly.

I had checked my engine oil both before the ride and again this morning, it is showing on the cross checked part of the dipstick and is a light golden color.  I have no knowledge about these engines so, though I have heard of a petcock and vacuum lines, I have no clue where to find them or how to check them.  I will turn the screw on the carburator to see if any gas comes out (I assume that is how to check if there is any gas in the carb.  I will be recharging my battery again today, though the lights went on I'm sure I wore down a lot of its power with repeatedly trying to start the scoot. 
I will check out info on the cold start valve, but don't understand why that would come into play when the scoot was running and in motion with WOT (which I assume is not idle).  I did not do anything with the kill switch but will try when I replace the battery.  Thanks

[Urbestfriend]

You might check the Drive Belt too....If the belt disintegrates,  the cords can get caught in the variator tying it up and stopping it.  Thus the engine won't turn over.

[Chris0381]

You have a 4t (older super8) whose spark plug is stuck in its threads. Sounds like the plug hasn't been changed for years nor have the valves been adjusted either then. The plug could be badly fouled and by the sounds of popping you mentioned, the valves out of whack.

Sounds like your bike is due for a much needed service of many small things essential to a good running engine.

Change oils, fuel filter, air filter, plug, carb cleaning, valve adjustments, CVT case dust cleaning, grease starter pinion and the torque thingy on the clutch. etc.

I also see they used glue in the factory to glue in the carb gasket. Cant rule out a chunk of old glue getting caught in a jet.

Download the service manual and start doing some of the things in the service checklist that you know hasn't been done to start.

Please google "how to remove stuck spark plugs" as I remember breaking 3 on an old Chevy Nova trying to remove them when I first started out in mechanics. Thankfully, it was a straight 6 Chevy 250.

[blackhawkfan]

Actually, the scoot is a 2013 with 1550 miles on it bought last May.  Whether the plug is stuck on its threads I don't know, it is very awkward to get to and whoever installed it must have been a gorilla because I can't turn it.  Though I have considered doing the valve adjustment (didn't seem too difficult from Wayne Kreps video) taking apart, cleaning and rebuilding the carb is something I cannot see myself doing.  Is there a way to spray some carb cleaner in there without removing it at least to give that a shot?  The valves were supposedly checked by the dealer when it had its 200 mile check .

[Chris0381]

For some reason, I thought all S8's were 2t after a certain year especially 2013. There is a nice youtube for removing a carb.

Lets start with spraying a bit of P-blaster around the plug threads and let it sit overnight or a few hours then try removal. Do not!!! use the SP socket that came with the bike, go to the parts store and get a good 3/8" drive spark plug socket and use a good ratchet with an extension. NOTE THE SPARK PLUG NUMBER SO THE PARTS STORE CAN MATCH THE EXACT SOCKET NEEDED.

I suggest removing that spark plug as first priority.

Do you have spark ?

Is your compression good ? Autozone may have compression testers.

Then its time to address fuel and air.Get the 2 easiest tests out of the way first. I believe you can test for spark without removing the plug.

Popping still points towards a valve/timing/sparkplug issue for what I know about engines. Overly lean engine can possibly pop or ping also. Not sure if the CDI ties into this also. Im new to bikes. Maybe bad gas also; are you using 92+ octane gas ?

[blackhawkfan]

What is P blaster?  Any particular brand i should look for?

[Chris0381]

P-Blaster is probably the most popular brand of Liquid Wrench used to free rusted bolts. You probably can get it from Walmart or any parts store and even some hardware stores.

The key is to get a good solid grip on the plug so as not to crack the porcelain or strip something. Thats why a good quality 6 POINT socket is needed and not that cheap lose fitting socket that came with the bike.

[Stig / Major Tom]

Sounds like you might still have the 2 year warranty from Kymco?
It is fully transferable to all owners (the warranty goes with the scooter - not the buyer) - but it starts 2 yrs from when first purchased & put on the road....not from production date, or model year date - but from when it was actually sold to the first customer.
A 2013 model, even if purchased used by you probably is still under full warranty.
I think you are correct - at 1500 miles your plug and belt etc. are probably still good.
But geez, I'd get that scoot to the dealer and have them remove that plug. It is a very small diameter plug and should not be very hard to remove.
Popping[/u] and hard start just might be a loose or not-fully-seated plug cap wire.....or the spark plug has not been cracked by trying to remove it, yes?
Let us know  what you are finding...
Stig

[Chris0381]

I assume this is a 150cc bike and not a 50cc thus why its a 4t and not a 2t. Yea, its under warranty still most likely. Although, they can claim the owner overtightened the plug.

If you can, take it in and play dumb. All you know is that it doesn't run and it stranded you out on the roads.

The question is though, how do you get these bikes to the dealer when they are 30 miles away and you drive a small car? Do you need to rent a truck when the issue can be something minor to fix yourself.

[blackhawkfan]

A friend of mine was just saying about the warranty, and I'm going to look into that.  I guess I will have to rent a truck and get it to the other dealer, who is 25 miles from me.  I just did not think warranty right off when this happened.  I haven't overtightened the plug because I never loosened it in the first place...I've got to go to Rent a Guy to get someone with the strength to do it.  I'm going to check the plug wire (I assume you mean that rubber cap thing that covers the spark plug hole--I did remove that in my efforts to even get at the plug).

Thanks!

[Chris0381]

That is a lot of time and resources.

What ever the outcome is, keep us updated to how the issue was solved so we can add it to the possible causes and solutions history of the forum.