my zx50 issues

[Shaka]

mine came from harbor freight just like yours....the other was a nice one...lmao     chinesse scoots suck, BUT we go to harbor freight and buy chinesse....RLMFAO....  a shop even done this last set, i did first ones...lol... hell, needing that much compression, 75 wouldnt even start it, would it, much less good??

Might be suspect!  Haha, I know I have a lot of harbor freight tools, but I don't expect much from them to begin with.  That way they usually exceed my expectation.  Seriously though, If you had multiple tests done with different gauges I guess 75 psi it is then.  Just seems too low to run well!  I would try a leak-down test just to make sure.  You can make a leak-down tester for less than $20. 

Beige is not a bad color for the mix ring.  You still probably want to go a little richer though just to be safe.  You want a nice brown color!

[thebatman]

i checked...yes it gets harder, both by turning fan and rotating kick...idk...never been that high

[zombie]

If it's good it's good!

[Shaka]

If it's good it's good!

Very true!  Still seems fishy to me though!  Ring end gap?

[thebatman]

is that where zombie says to set it standard (1-1/4)and turn out 1/4-1/2??   care to crash course......again, i am sure its in a thread sumwhere..

[thebatman]

i just thought of a real good, dumb ?..... how in the world do you mess with the 2 screws to find wot AND THEN turn right around and mess WITH THE SAME 2 SCREWS to fix the 1/4 and get it in sync with wot??    seems it throw the other off??....   rode motorcycles, dirt bikes, but never did much work on them, can you tell??  RLMFAO..... like workin on cars....guess i better not even ask about this "indexing" the plug i saw......

[Shaka]

The ring end gap is the gap between the ends of the piston rings.  If they are too wide you will loose compression, as they let too much air squeeze past.

The 2 screws on the carb only effect the idle circuit.  They have no effect on WOT.  Once you set them for idle, you leave them alone.  The main jet is the only adjustment you really have on the stock carb that will change anything above about 1/2 throttle.  That is one of the benefits of an aftermarket carb is they are much more tuneable!

Indexing the spark is real easy!  You just make a mark on the insulator in line with the open side of the electrode.  This way you can tell which way the spark plug is opening when it's installed.  You want to align the open side of the spark plug with the exhaust port.  Don't over-tighten the plug trying to get it lined up though.  That is why you may need some thin washers to get it to line up right.  Some plugs index with no washers.  You have a little "wiggle" room with the torque to get it where you want it, but don't excessively tighten it down trying to get it lined up!

[thebatman]

i thought one was idle, the other the air/feul mix... glad i just kept staring at it last night..  thought/ hey, the air mix screw controls the oil inlet right??                                                                  is there even a benefit to indexing?

[thebatman]

All mine ever says is "feed me". You may have a short in the lighting circuit. That could pull the voltage down enough to miss fire the stator. Maybe the plug was just worn tho. If your idle circuit is too lean you will see 2 things, 1 is the scoot will make NO running sound when you are cruising, and shut the throttle. 2 is the idle will rev high for a few seconds (10-20 sec.) before returning to normal. you should be able to fix that by adjusting the air mix screw. Do the standard adjustment, and give it an extra 1/2-3/4 turn counter clockwise. Then bring the idle speed back up using the slide adjustment screw. Also check the 2 green wires,, where you did the de-restrict. If they are not soldered, then do so, or at least use a BUTT Con. to secure the joint. you can loose output from the cdi if that joint gets funky.

[thebatman]

Very true! Still seems fishy to me though! Ring end gap?

                  thought about this again, got up  warmed her up and checked compression again.... i do stand corrected TO A POINT.... made a tight connection and i did get 95psi but not anywhere near this 120+psi......

[Shaka]

i thought one was idle, the other the air/feul mix... glad i just kept staring at it last night..  thought/ hey, the air mix screw controls the oil inlet right??                                                                  is there even a benefit to indexing?

The air mix screw only effects the mix at idle.  Once you begin to open the throttle the slide controls the mix from there on out.  There are no adjustments to be had effecting the oil. 

There is a benefit to indexing the spark plug, but it's not going to be very noticeable in an un-modified engine.  It directs the flame front towards the exhaust port which can help prevent detonation as well as slightly increase efficiency!  It is more noticeable in a larger displacement cylinder, or a cylinder where the bore is wider than the stroke.  In a cylinder like that the distance from the spark plug to the exhaust port is greater.  It is the same idea as the off-set spark plug in the head.  Notice they are always aimed at the exhaust port.

95 psi doesn't sound as bad as 75 psi!  I think it is still a little low, but in the "it will run" range.  Might not be the "healthiest" of engines though.  Is it a new cylinder?  I can't remember what/if you did anything to the engine.

[thebatman]

what up shaka?.... ok this may b a touch long, sorry.. well this a.m after the (4 sake of argument retest)..i did index the plug and i did turn the mix screw counter 1/4 turns.. i rode about 70miles today and I WOULD SWEAR it was different, carb actually sputtered couple times, i used sum oil too, bout 3-4oz today!! gotta be to much..and i think it was a bit slower and top end was "flatter"......   i have A jet from previous carb. i "cleaned" this jet supposedly to big, i thought it was gonna be same size but guess not?? idk, it was clean tho..lmao.. i tried to use same size to clean buuuut.. how do i know if it is to big??  figured id throw it in.. y is spacer hole bigger than intake & carb hole??.. guess i have to do another set of chops??  what will it look like if sh**?? i have only redone stock with new piston, rings, gaskets, cleaned cyl walls,  different oem carb, technigas exhaust on the engine....(springs, rollers,tires,as of today: getting sids var, all new springs & rollers, want reed cage)

[Shaka]

If you're still running the stock engine and the only mod you have changed is the exhaust.  Your main jet shouldn't need to be much bigger.  If you run a K&N filter you will have to up-jet for sure.  I'd think if the stock main jet size is 90, you may only need to go with a 92-94 with just the exhaust.  With the filter also, maybe as big as 94-96, just a guess though.  The cvt tuning is where most of your improvements will be had beyond the intake and exhaust.  You won't need to re-adjust the carb for any changes made to the cvt.

[thebatman]

thanks for answering, well i put the jet in just now, it is a "cockhair" bigger.. i put a sewing needle in it and the eye caught the hole in jet for the oem one,   for the one thats bigger, the needle went thru.. so i have no clue what size it is, only one i had to even try at the moment,  hadnt cranked it yet... why the  plastic "spacer" in between the intake, carb?

[Shaka]

Those jets are stamped with the size around the edge.  You have to remove it to see it.  Mine had the little Keihin star and then the #
That spacer/gasket is there to possibly help seal, or to add length before the sharp bend in the manifold.  Not really sure looking at it!  The hole in mine is exactly the same size as the manifold hole and slightly bigger than the carb outlet.  It doesn't restrict the flow in any way.  The sharp bend in the manifold and the tiny reed block are much more restrictive!  You can try without the spacer, but it probably won't help anything!