Jetting Recomendations ? -- NOW MORE ISSUES ! :(

[bubonik]

Hi Folks
I have an '83 Areo 80
with a 24mm OKO Carb
I have been playing trying to get it as happy as i can, it's pretty good so far
I know very little about bike carbs but have been learning more everyday
For this size of carb on an '83 80cc
what kind of jet size should i be running ?
I have the filter about 70% covered to cut down my air intake, as i found it was overheating a lot
I also had the original jet it came with in there, a 107
right now, i have a 98 in there, have played with the A/F mix and the filter covering
i'm fairly happy with it, but still find it's losing power after about 10 minutes of driving
and flat power after about 7/8 throttle

my A/F is about 1.25 turns out
My current jet is 98
70% covered filter

please feel free to give any suggestions on how to change this set up to make it better

Thanks !

[paulpauly7]

check your rollers they have alot to do with tuning

[bubonik]

i replaced them about 6 months ago, with a lighter set
they are currently 14.5 Grams
instead of the usual 16 Grams
before i had started trying to do any tuning to it, that was my first attempt
since then i have gone to a 2000 rear spring, so should probably go back to 16 Grams weights

[bubonik]

So I finally got a new OEM belt to replace my old worn out one
a snug fit, but it's on there
now i'm am finding, the low end is totally gutless, so much so it will stall on start from a light
once it get's moving it's ok, but the first 15-20 seconds are garbage
I realize i have lighter weights than is normal, but shouldn't that allow more rev before engagment ?
wouldn't that make it easier not harder ?

Another question
the A/F screw. is out more gas or more air ?

I sure hope you folks can help me figure this out !!

[patthesoundguy]

Don't choke the carb 70%, that totally defeats the purpose of the huge carb, IMHO. Open it up jet it with what it needs and ride the living crap ut of it with a big grin on your face for how much top end you prob opened up B-) If your bottom sucks maybe the pilot is wrong so its just falling flat when you punch it. The spree kit I have with the 21mm carb on it is running nice with 45 pilot and 95 main. So I think you may be in the ballpark try going up a pilot size from what you have in it and see if it improves. And yes lighter weights do mean shifting up later or staying in lower gear longer in the either rpm ranges. Stock for the aero 80 is 16 or 16.5 gram isn't it.

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[bubonik]

yeah, it's 16
I have 14's in there now
I have a 98 Jet in there at the moment, on a 24mm Carb
I don't know what Pilot is in it, how can i tell ?
it was running fairly well, BEFORE i put the new belt in
now it falls flat and start, once i get it going, it's fine again
I'll open up the carb and play with the jetting a bit more tonight and see what i can come up with

can anyone speak to my A/F mix question ?

opening the A/F screw gives more ?? Air or Gas ?

[kingkamehameha]

Read up on the jennings articles. Also you dont need that carb its too big i would switch back to a stock one.

[bubonik]

I don't have a stock one to switch to
when i bought the scoot it had a 28mm on it
a really beat up leaking 28mm
so i bought a 24mm to replace it

looking around, it sounds like the OKO has a 42 Pilot
i'll have to find some other sizes
i'll keep poking !!

thanks for the input so far !

[bubonik]

thanks for that Jennings book !
didn't even nkow that existed !!

[patthesoundguy]

The pilot jet is responsible for starting and idle and up to 1/4 throttle.
If you have one of those plugs in the float bowl of the carb that allows main jet swaps with out removing the float bowl that explains, why you have ts seen the pilot jet pull the float bowl and look there are 2 jets there, main jet in the centrw and pilot of to the side. Yank the pilot and see what size it is. It may be going lean in the lower ranges and it wasn't so much of an issue before the tranny changes, that's my theory anyway.

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[bubonik]

I pulled the pilot last night, it's a 45
and right now i have a 96 in for my main jet
i moved the clip on the needle to the centre of 5 spaces (it was on the second from the top)
It did seem to make it a bit better
but still really bad off the line, throttle doesn't seem to affect it as much as speed
once it's moving about 5 Km it switches gearing a bit and runs good
I'm going to pull the belt again and check my Variator and rollers again

Should there be any grease or anything on the engine output shaft ?
where it and the variator boss (inner metal bushing) meet ?

[bladecki13]

Sounds like your belt is probably the wrong size... its starting off in a higher gear and straining the motor down because you did say it was tight on there, check that or even put the old one back on and see where it sits on the rear pulley and compare to the new one!! hope this help a little!!

[patthesoundguy]

My aero 80 kinda falls flat in the bottom end since I put Dr pulley sliders in because I put in the wrong weight. I put in 16 gram instead of 15 or 14 gram. I didn't realize I needed to go lighter than stock. What makes this relevant is the possible wrong belt size, if it is too wide its not going low enough gearing, just like with my heavy sliders gearing up so quick I'm not really staying in the lowest gear ratio long enough for it to be that useful. I can't wait to hear about the better performance with the bigger carb. B-)

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[paulpauly7]

no grease keep it all dry and clean

[patthesoundguy]

no grease keep it all dry and clean

It made a big difference when I degreased my aero variator. I have lighter Dr pulley sliders on the way, I'll be doing wheelies again

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