80cc Mystery

GoldenMotor.com

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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Looks like your base gasket was leaking and it ran lean. How long have you had it? Talked to the seller (warranty) yet?
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
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lean, i keep hearing those kind of words...lean means too much (oil, gas, fuel, air) PICK ONE please.
Traditionally when someone is talking about an engine and says "lean" they mean less fuel in the air+fuel mixture. So naturally this means more air.

Lean oil in a 2 stroke premix means a light oil in the mix, less oil per quantity of fuel. (Confusingly enough, when oil is mixed heavy in the gas, it can mean a lean air+fuel burn situation)

So anyways, yes see my Saber special.

Lastly - what exactly is the problem now?
 

MrLarkins

HS Math Teacher
Jun 17, 2008
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problem recap...

0 to 20 mph runs smooth as butter
20 to 30 mph not possible (it use to get up to 36mph, but not anymore).
20+ it gets more gas (hence the black, oily spark plug), but the motor won't accelerate past 20mph. It gets the shimminy shakes and acts like its flooded.
 

MrLarkins

HS Math Teacher
Jun 17, 2008
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no, someone told me to move it down 1...so i did, then i went down 2...when i get home (at work now, goofin off :p) I move it up and post back
 

MrLarkins

HS Math Teacher
Jun 17, 2008
487
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You are definatly lean... Look at the pic of the spark plug, Might want to raise the needle in the carby (lower the clip) one slot......Parts all look ok though. Also when you put the piston back in the cylinder make sure you line the opening of the rings up with the little pins in the grooves...

8oz @ 20:1 = 160oz of gasoline 128oz = 1 Gallon So 8oz of oil to 1 Gal and 1qt of Gasoline

Any QUALITY oil..... I use Amsoil Sabre....
here's the guy MISTERIGHT2_99!!!
 
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misteright1_99

New Member
Mar 21, 2008
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In this post Norman shows you the internals of the carb. You need to read it an familiarize yourself with it then you might want to try moving the clip ONE notch and riding your bike and see what you think. And then MAYBE try another slot and TEST RIDE ETC. Looking at that spark plug I think you are running lean so you should start with moving the clip DOWN 1 slot to increase fuel to air mixture....

http://motorbicycling.com/f4/carburetor-pictures-how-install-rebuild-195.html
i also moved the 'c' clamp to the lowest position in the carborator...isn't that suppose to give the most oxygen in the mix? i don't think i'm getting maximum combustion...lots of oily black on plug...and i mixed 4oz 2 cycle oil with 1 gallon gas, that's the right mixture, right?
no, someone told me to move it down 1...so i did, then i went down 2...when i get home (at work now, goofin off :p) I move it up and post back
here's the guy MISTERIGHT2_99!!!
Read the first paragraph one more time CAREFULLY!!!!!!!
 

MrLarkins

HS Math Teacher
Jun 17, 2008
487
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Arkansas
Read the first paragraph one more time CAREFULLY!!!!!!!
hmm, i read it 3 times, and I still read the same thing...
misteright1_99 said:
you might want to try moving the clip ONE notch and riding your bike and see what you think. And then MAYBE try another slot and TEST RIDE ETC. Looking at that spark plug I think you are running lean so you should start with moving the clip DOWN 1 slot to increase fuel to air mixture....
it still says move down 1 slot, as I did...pablo says move to top spot (up, not down)

what am i missing? now i'm really confused. heck, i'll just try all slots!
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
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hmm, i read it 3 times, and I still read the same thing...


it still says move down 1 slot, as I did...pablo says move to top spot (up, not down)

what am i missing? now i'm really confused. heck, i'll just try all slots!

Previously you wrote:
MrLarkins said:
...it gets more gas (hence the black, oily spark plug), .......acts like its flooded.
So....based on this I THINK you need to be more fuel lean.....moving the e-clip up makes it more lean mid throttle by keeping the needle lower in the carb jet path.

What Norm says is correct.
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
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Also - what the other guys are saying (and I'm not necessarily disagreeing with them) - based on the initial plug pictures, it looks a bit lean. But your engine is back together and we have moved beyond that, right?

Seems to me you should try the top notch or the second notch and go from there. It's gonna turn out that your issue has nothing to do with the needle groove.

Where did you get your new gaskets?
 

MrLarkins

HS Math Teacher
Jun 17, 2008
487
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ok, i am such a noob...you guys are a bunch of help! top notch it is

and just for the record, the wording lends itself to be confusing...i mean really...
pablo said:
more fuel lean
i'm getting it now, but thats confusing...more fuel...lean? how bout, more air or less fuel
 
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Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
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ok, i am such a noob...you guys are a bunch of help! top notch it is

and just for the record, the wording lends itself to be confusing...i mean really...

i'm getting it now, but thats confusing...more fuel...lean? how bout, more air or less fuel
That's just bad word choice on my part (sorry), but I meant what I said....IOW - more leaner, or just leaner…….less fuel = more leaner=more fuel lean….crazy asss English langauge…

Properly, moving the clip to the top, without changing other parameters will result in less fuel in the air/fuel mix.:p:eek:;)
 

MrLarkins

HS Math Teacher
Jun 17, 2008
487
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i moved it to the top...no effect on problem

i don't need to be moving to have the problem occur. standing still with clutch engaged, i can turn the throttle and at some point, the motor starts acting up...maybe I can get a video of it soon
 

Ghost0

New Member
Mar 7, 2008
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Bellingham, WA
Sounds like it is starving for fuel and since you moved your clip up and down the needle and that didn't work here are a couple of things to try.

Float level too low causing fuel starvation at above idle condition

Plugged fuel filter either in tank or auxiliary if you have one.

Clogged jet in carb.

Clogged float needle in carb.
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
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Pablo said:
It's gonna turn out that your issue has nothing to do with the needle groove.
OK I agree with Ghost0 (imagine that) it sounds like fuel delivery is impeded - I wonder now maybe the taper of the needle is funky. Do all the easy stuff first...make sure fuel is flowing well.

Oh yeah - thanks for the video - it really helps with the troubleshooting.
 

MrLarkins

HS Math Teacher
Jun 17, 2008
487
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float level is at its maximum

fuel filter queen

jet in carb is clean

float needle in carb is clean

QUESTION:
is it possible that a misbalance on the inside might cause a rpm threshold?