Cy50 Jog newb! please help! carb issues

[zekesil]

Hey Guys, i was forwarded onto these forums from a helpful member of a simular forum! hopefully you guys can help me !

OK! please bare with me! i am in some desperate need of some guidance, i just purchased a cy50 jog scooter in need of some light repair, having a car mechanic background, i thought i would be fine!

here is my symptoms -
scooter does not like anythng above 20-30% throttle, anything above the scooter will bog down and loose speed/conk out,
and
scooter is very smokey after about 2 mins.

ok so, i thought no worries, its running to rich? adjust the needle in a tad and see how we go? negative, moving the needle in our out makes no difference to the bogging down. nor smokeyness, which makes me think oil?.

to be sure of what was in it, i went to the shops and purchased some scooter specific 2 stroke oil. no difference, so now i have removed the carb from the engine which from the research i have done, believe is the 1E40QMB? again could be wrong.

on inspection of removing carb, i noticed 2 nipples with no lines connected. they are pictured below - number 1 and 2.


my questions!
what are 1&2 supposed to be hooked up to?
is the following correct
3 Fuel main
4 Fuel return of some sort (not sure line from tank goes here)
5 oil feed?
6 mixture needle
7 idle ?

could there be a problem with the oil injection? should i just go to premix?
why would it be bogging down
what is the factory needle settings?

thats it for now,
i apologise for the massive amount of questions, and really hope someone can help me, i have tried to do alot of research, sadly have not come up with much.
thanks in advance.
Zac

[Fox]

1: overflow (leave it open)
2: bowl drain (usually has a tube that dangles toward the ground)
3: fuel inlet
4: vacuum port for a vacuum actuated fuel valve (pic below)
5: oil injector line
6: idle speed
7: idle mixture

I think you need to take the bowl off the carb and remove the jets and spray the crap out of it with a can of carb spray.

Pre-mix is always the better option so you don't have to worry about whether the injector is working or not. If you disable the injector plug off that port.

The fuel valve is a safety feature. It shuts off the fuel flow from the tank when the engine is off. Spring loaded diaphragm inside. Engine vacuum opens it. blah blah blah...

Tank mounted valve:



Frame mounted:

[zekesil]

Thanks very much for your speedy reply!
i have removed the jets, cleaned them out, they look fine .. i didnt realise i was adjusting the idle mixture rather than the mix
*red face*
so, what is the factory position? where is a good start point?

[stepthrutuner]

As 50 said spray every passage you can find everywhere on the carb throughly.

[zekesil]

ok update,
i put the carb back together, (gave it a good clean whilst it was apart).
now that i am playng with the mixture needle, slight improvements have been made, however, i still have anythinig above 50% throttle bogs down heavily, i can reach top speed at like 30% throttle? i am really not sure whats goinig on here.

also, its still puffing out alot of smoke, i disconnected the oil feed line whilst the engine was running, expecting to see some sort of pulse of oil? but none, there was oil present at the tip of the line, but it was not visually beinig pumped? should i try changing to premix?

[Fox]

[quote author=zekesil board=2help thread=544 post=6207
so, what is the factory position? where is a good start point?[/quote]

My scoot likes the mixture screw at about 3/4 turn from seated but each scoot will be different. Temperature and elevation will play a role. Once the weather gets hot I'll have to re-adjust it most likely.

Start at 1 1/2 or 2 turns out and warm up the engine real good. Then turn it to the right til the engine starts to stumble and then turn it the other way til the idle smooths out. If you try to adjust it when the engine isn't warmed up thoroughly you'll be chasing your tail til it gets hot but before you do any of that, spray carb spray through every single passage in the entire carb like stepthrurunner said.

[Fox]

Apr 4, 2010 23:37:58 GMT -5 zekesil said:

ok update,
i put the carb back together, (gave it a good clean whilst it was apart).
now that i am playng with the mixture needle, slight improvements have been made, however, i still have anythinig above 50% throttle bogs down heavily, i can reach top speed at like 30% throttle? i am really not sure whats goinig on here.

also, its still puffing out alot of smoke, i disconnected the oil feed line whilst the engine was running, expecting to see some sort of pulse of oil? but none, there was oil present at the tip of the line, but it was not visually beinig pumped? should i try changing to premix?

Yeah. Try premix. I use 4oz/gal. I'm thinking maybe you have a low compression problem causing incomplete combustion maybe.

What sort of air filter does it have on it?

[zekesil]

currently, the carb is open to atmosphere whilst i had it apart/tuning it. :S i think it might be a low compression issue aswell.
90gtv!? are you out there? i heard you were the wizard.

[Fox]

Well, it'll run differently with a filter on it that's for sure but the smoking is problematic...

If the pipe is full of un-burned 2 stroke oil it'll smoke.

Try putting your hand over the back of the carb to partially block air flow and rev it on the stand and see what develops.

Also, from the pic of your carb I can see it has an electric enricher unit. It could be bad and if so the thing will always be choked (Enriched) and that will cause it to run like sh*t.

The enricher unit is in rich mode until the engine is running for a couple of minutes and then it shuts down the enrichment jet but if the enricher unit is faulty then the enricher jet is always open causing a richer than desired mixture resulting in a crappy running engine and smoke.

Start the engine and test for 12 volts to the enricher. If it has voltage then test the unit itself by hooking it to a 12 volt source and observing the protrusion of the needle on the unit. it should extend outward from the unit after a minute or so. the unit will feel warm to the touch after a time as well.

[zekesil]

jmStar, you are being alot of help, thankyou.

i have now changed to premix, no more massive amounts of smoke. fantastic.
however i am still havinig the 20% throttle issue, the scooter will bog down unless the perfect amount of throttle is given, it would appear that adjusting the mixture needle only changes the mixture at this specific throttle positon, anythng after 20% bogs down and makes a loud droan noise. does this still sound like the enrichner unit? i guess i will check tommrow night? does it sound like anything else?

thanks again for all your help, really, it is really appreciated.

[Fox]

Okay look zekesil,

The Idle mixture screw only affects the idle circuit of the carb. It has zero, zip, nada, nothing to do with the high speed mixture. Hence the name: Idle mixture screw. Trying to get the revs higher by turning that screw is absolutely futile. There are three jets in the carb. An idle jet controlled by the mixture screw, an enrichment jet controlled by the auto-enricher, and a main jet controlled by how far you twist the throttle.

If you are having difficulty with the high-end then I would suspect either a compression issue as stated before which could point to a mechanical problem like rings or a carb issue like an auto enricher that may be faulty which could/would cause it to run like a weed whacker that has the choke on all the time. They will rev but not all the way.

I posted how to check the enricher previously so do it and then get back to us.

Here's a test: Pull the spark plug and look at the color of the firing end. I am willing to bet that it's pitch black. Sometimes a new plug will cure all ills. These 2 strokes can be finicky.

[zekesil]

And BAM just like that, i now understand i had the complete wrong mindset how this all works.. apologies for your frustration.. its pitch black indeed, my next post, i will tell you how i went with testing the enrichner and plug.
if i could buy you a beer i would.
Zac

[Fox]

Cool!

You see if the enricher is faulty or has no voltage to it then the enrichment jet is providing an extra amount of fuel all the time to the combustion chamber and that causes the engine to crap out once it's hot.

That extra fuel is a good thing when the engine is cold but once it gets hot it's your enemy.

The unit may be okay and just not be getting voltage. Gotta check it out.

NOTE: It may be fine which would bring us back to square one but at least we've eliminated a couple of suspects.

[zekesil]

OK, jm star, i quickly ran down and tested it, there is no 12V at the enrichner, however, on removing the enrichner unit, i have found its default setting to be extended, the needle attached to it is spring loaded and hooked up to 12v makes no difference, this is a bit of a puzzler?

[Fox]

No the needle is supposed to be springy.

You first get a piece of paper and mark the needle protrusion on it and then you hook the leads from the choke unit to a 12 volt source and observe it for 2 minutes, the needle should extend outward by a few mm's or so.

The spring is what controls the extension. It's an electromagnetic coil that heats up the spring. Heat expands....spring gets longer...

The voltage is only present when the engine is running. Turning the key on won't or shouldn't apply voltage to the enricher.