Verbal Diarrhgnonis

[kanbisk]

Sorry to nag, folks. I'm eager to get this ordered - had to come in to work on the pushbike today... Does the above jet look like the right one? Failing that which carbs do the kymco 50s use and I'll work it out for myself.

Thanks
Matt

Matt,
Make sure you know what you ordering.
Look on the carb for part no or some kind of code or something with numbers on it.
2 and 4 strokes are use different carbs.

if you rush and order items are not the one you wanted, you be wasting time and your pocket money.
Thats why there is "FORUM" to we talk to each other to solve problems.

LATERS

[Matty]

Thanks kanbisk

I'll pull the thing out and give it a good looking at for a part number tonight.

I'm thinking i'll just replace the whole carb - a new slow jet is £9 and a whole new carb is £25. Crazy world...

Think I may have killed my warranty! At least I get to learn a bit about bikes.

Thanks
Matt

[Matty]

UPDATE: Took the battery for testing. The chap said something like "1256". No idea what he meant, but he said it should be fine. I'll test the actual spark and post a video this weekend.

[kanbisk]

UPDATE: Took the battery for testing. The chap said something like "1256". No idea what he meant, but he said it should be fine. I'll test the actual spark and post a video this weekend.

Maybe he ment 12.56 volts ?

LATERS

[JustWantToRide]

12.56 volts would be in the middle of the good range.  That eliminates a lot of the possibilities.  I think your charging system is probably fine - unless you've been keeping it on a charger (which would mask the results).  Checking the spark is the next cheap/easy test.  Eliminate possibilities wherever you can...

[kanbisk]

I got my suspicion on spark plug also - I had another scooter before, just after put in piston, cyclinder and brand new plug, after 2 miles engine died. After 2 days checking everything, something inside me said put new plug and BANG !!!!!   there it was, started sraight away.

Thats what happend to me.

LATERS

[Matty]

Hey folks. Just for clarity, I already replaced the spark plug with a brand new iridium one, and it made no difference at all. I know it could still be other electrical components so will post a video of the spark shortly. For reference, below was the condition of the old spark plug when it came out.

[Resolve]

Looks like it was leaning out and runnign hot

[Matty]

Hard to know how much of this was due to the air intake (from the air cleaner to the carburettor) being disconnected - I've no idea how long it had been running like this, but at least 3-4 months since I've had it.

Anyway, new carb is in the post so we'll see where that goes - will also have new auto choke on it so that might help?

I've really no idea what I'm doing here...but learning fast. ish

[JustWantToRide]

Looks like a typical dry fouled plug to me.  A weak spark is still my number one suspicion, followed by valves out of spec - but I'm also concerned about low compression or a malfunctioning choke.  Seeing the spark should help.

[Matty]

ok. just replaced the whole carburetor with new. Still same problems. In fact even harder to start.
Finally got it running - idle problem might have been due to a loose throttle screw - now adjusted and idles ok but I have to have it at pretty high revs to keep it "idling". Not enough so that the clutch engages though.

That done, I turned to the spark. Just had a look at the plug which is only a couple of weeks old and it's black black black. Maybe from all my turning it over to try to get it started? no idea.

Below is an image of the spark plug. video to follow shortly.

In summary, I'm back to square 1 now. Got a running bike, but with no acceleration...

Next step change the battery? I had just been charging when I took it for testing. Could have been wrong. I'm thinking of biting the bullet and just taking it in to the garage.

[Matty]

[kanbisk]

Matt,
I not trying to be funny but it looks like to me (what I can see from video) WEAK spark.
Try testing the coil, HT lead and plug holder.

Also try reading these 9 reasons of why scooters dont start.   http://www.gsmotorworks.com/scooter_starting_tips/c50_r45/Scooter_Starting_Tips.cfm

LATERS

[Matty]

Thanks Kanbisk. I'll get the battery double-checked and maybe just buy a new one.
Any idea why the spark plug might have gone black so quickly?

[kanbisk]

Hi Matt,
This is what I found out,
"A black dry fluffy colored plug is caused by deposits from a carburetor that is running too rich (too much gas),or excessive idling on some engines.
Black smoke coming from the exhaust is a sign of a rich air/fuel mixture. The rich air/fuel mixture must be repaired before installing a new spark plug.
Common causes for a rich air/fuel mixture are:
dirty air filter.
air mixture screw or carburetor needs adjusting.
choke is sticking.
carburetor float height is out of adjustment or float is sticking open."

Just installing carb wont help, you need to adjust CO levels.

By looking your pictures, it looks like running too rich - either too much petrol OR less air.

LATERS