MY ZX50 O.E.M CARB TUNING

[thebatman]

yeah, even trying some different oil and they couldnt even explain how my jetting could go lean even when 2 SIZES bigger now.. will try once more to upjet and then imma try a downjet?.  dont understand that at all but the dam air/temp/humidity dropping has to be an issue somewhere/somehow...idk?....did have an idea thrown at me with the rpm variation: the oil injector is going out, and cant mix properly?...wth?? injector??, pump, yeah.. but she dam sure uses the oil.   so i wouldnt think an oil issue.....

[wordslinger]

..feel your pain...


..it ran well this morning, a bit slower than last night, but in a head wind..

..however, i wish i had chopped this plug at wot...

..damned if it didn't feel lean at @ 58 degrees this mornin'..

..the chops on the c8hsa plugs llast night looked spot-on...with a 102 jet..

..rained all the 17 miles home this afternoon, sssso...

..tomorrow is another day, as i can't tune on wet roads..

 

[art]

  If your plugs are still showing lean I can't see going down in jets. A coil burning too hot could be an issue.

[sidthesloth]

Still sounds like an air leak. Could it be a leak that is closing that is causing the rev change?

[art]

  That would be my first guess    seems to have gone over it several times. I have had elecrical act like this but it usually don't last to long before something go's out completly 

[thebatman]

well i remember when word, shaka had mentioned going down in jet size. word talks about different jets for different seasons, so i was wondering about that being an issue...i hate riding her but i have no choice but ride and now with that rpm change crap uphill...nasty belt tug these days...i guess its belt tug: can feel it jerk/hit different shift patterns then at 15-17 shell take off...i am wondering if i dont feel tug AND slippage..cvt was closer 2 weeks ago also. guess i need to take shroud off and check for a leak..never found one yet. could i spray the oil seals after running and see?(if i can get belt cover off while running).. i figured id try once more, then i guess just ride till she blows...idk.. cant even tune anymore if this is not corrected....

[sidthesloth]

G'day batman, that with the revs creeping up and down, you don't suppose that could be the belt slipping do you? Under load it slips and then grips, while your speed stays the same your revs change, as it gets worse, your speed will be affected more. Think of a slipping clutch in a car. When I bought my Hilux, in top gear, if you put your foot down the revs would increase but the speed would only increase slowly. Just a thought.

[thebatman]

good morning sid...well i wouldnt think the belt. when im going uphill, all seems fine then rpms drop a bit (lets say about 750, no tach), every few seconds you can hear rpms jump back to where they should be, then drop the 750 again, then pick it back, then drop. it feels and sounds like she gets a shot of gas/oil/??? and corrects for a second then again. speed seems to stay correct/steady, just rpm change..can hear change, sometimes actually feel the change, like a "power surge" of sorts...idk..didnt do this before either..

[sidthesloth]

Oh, ok, if it was slippag then the revs would go up not down, maybe crud in your carb, but that would not be as consistant in the change. Sorry i can't help with this. Do you have another carb you can try?

[thebatman]

i wish i did.   love to find a 16-17.... yeah, this seems to be a gray erea for everyone.   ..makes me miss shaka and zombie even more with their zx knowledge. 

[sidthesloth]

Did you check your cdi bridge? making/breaking contact might give that effect.

[thebatman]

actually i never did since the dying out had stopped with the petcock change...the cdi has entered my mind but i way suck with them meters..

[sidthesloth]

What about just checking the bridge you used for the rev limiter? maybe the rev limiter is coming in sometimes.

[thebatman]

this new issue, i dont think is limited, feels like a surge of power/torque for a few seconds(making it correct, then rpm fall a tad again,then correct, then down, then correct). flats seem to be ok, just can tell on a hill with this.

[art]

 You got  a crazy thing going on and with out seeing and hearing it's hard to say because fuel ,air or electronics can have the same effects  Need to try some tests,like what happens if you run with no air filter? Try resetting your float? Check your bystarter,pull and clean? Not sure what to do next 
 The lean condition on the plug  points to air leak  Not enouph fuel being delivered  Not enouph Oil  crap in the main jet  The tank,the gas cap is vented properly?
 If the basics don't get it I'm back to electonics.