Power loss and bad idle

[604scoot]

Hi guys, first thread. I have worked with these bikes for awhile but i am stuck. After installing a g2 reed valve and windowed piston i have bad idle and terrible low end power. Before i installed the kit it seemed to perform better. And it will idle for 5 or 10 seconds once warm but always falls on its face. I have checked for air leaks everywhere. Seals are fine. Gaskets everywhere are new and have added high temp gasket sealer. I tested them with starter fluid too. I am almost certin there is no leaks. It seems fine once cruising and top end power seems fine. Plug is brown.

66cc with a balanced crank ( smolikss way of balancing by drilling two holes in crank)
Name brand bearings
Polished exhaust port
Stock port size
Stock timing and cdi
36 tooth rear
Pz20 carb with needle fully rich ( seems better here)
75 main jet
Ngk plug
High compression head with a good squish gap
Name brand scooter expansion chamber ( worked great without reed setup)
40:1 ratio with 91 octane

Its odd to me that the air screw or main jet doesnt do much if i change it big or small. 68 70 72 jet runs not so good but 75 seems allright. And the air screw seems better almost fulling screwed it. Starting from a stand still to get up to speed is terrible and cant idle. I have zero clue and feel like ive tried it all. Maybe the carb is no good or cdi is bad? Wires are wired good and no air leaks. I also have the carbon fiber reeds in the g2 and tried the other white finerglass ones. Nothing changed.

 

[DAMIEN1307]

40:1 ratio with 91 octane

40:1 is a mistake...breakin should be at 20:1 or 25:1 depending on motor and ALL 66cc common China Girls should never run less oil than a 32:1 ratio after breakin is over and hopefully a good full synthetic after breaking it in with conventional oil.

As for the other considerations like your choice of carby, choice of reed valve, (I use the OZ type myself), what jets will be needed with the carby and windowed piston and reed valve as well as choice of exhaust all make a difference.

That is why we all recommend only ONE change at a time so when running into problems like this, it is much easier to diagnose the problem...Right now you have too many variables in the mix.

 

[604scoot]

40:1 is a mistake...breakin should be at 20:1 or 25:1 depending on motor and ALL 66cc common China Girls should never run less oil than a 32:1 ratio and hopefully a good full synthetic after breaking it in with conventional oil.

As for the other considerations like your choice of carby, choice of reed valve, (I use the OZ type myself), what jets will be needed with the carby and windowed piston and reed valve as well as choice of exhaust all make a difference.

That is why we all recommend only ONE change at a time so when running into problems like this, it is much easier to diagnose the problem...Right now you have too many variables in the mix.

Its allready broken in. Like 6 tanks before this reed conversion. As for too many varirables? I only windowed the piston and installed the reed valve. Everything has been the same. All i tried to do was tune the carb to the new setup

 

[Chainlube]

Sounds like a rich bog to me, try the 72 jet again and move the clip up. You'll have to play with it for a while to get it right.

 

[604scoot]

Thank you, i will try 72 and move the clip up one notch. Also on a side note i put a newer plug in. Gapped at 0.30, same as last and it worked a bit better. But the weather just got colder. Let me try jetting it leaner and i ll report back

 

[Chainlube]

Thank you, i will try 72 and move the clip up one notch. Also on a side note i put a newer plug in. Gapped at 0.30, same as last and it worked a bit better. But the weather just got colder. Let me try jetting it leaner and i ll report back

If it just got colder, try moving the clip up to the middle with the 75 jet. Cold air is denser.

 

[604scoot]

Will do. Going to do now.

 

[604scoot]

If it just got colder, try moving the clip up to the middle with the 75 jet. Cold air is denser.

Hey so i put it two clips up like you said, and kept the same jet. I didnt notice anything and it still dies on idle. No matter how much i play with air screw or idle screw. It will obvs idle high and not die but it has to be high. And if i set the idle high, and if i drive normally, it will take a long time to go down to a normal idle. ( sounds like an air leak but im certin there isnt)

 

[Chainlube]

Run it the way it is until it's warm. Get a spray bottle with some water, with it idling high, squirt some water on all the unions of the carb to cylinder. Also hit the head and base gasket, plus the case seal. If there is an air leak, it will stall. If no change, then take off the side covers and check the crank seals.

 

[604scoot]

Allready tested for air leaks multiple times. I ordered a new carb. Comes today. Will report back