Break In New 80cc break in weird noise + low performance?

[Street Ryderz]

It idles without surge, the idle screw is in pretty far. If i try and unscrew it, the engine will die.

These Nt carbs are usually very rich stock and dont require much of an air gap at the slide to idle so there must be a restriction of fuel flow thru the jet or the atomizer tube or the needle may be slightly bent limiting flow past it ! You could try the other carb and see if that does the trick or go thru that one the only other thing I can think of at the moment is an exhaust flow restriction can also cause simmular conditions.

 

[micromaster22]

These Nt carbs are usually very rich stock and dont require much of an air gap at the slide to idle so there must be a restriction of fuel flow thru the jet or the atomizer tube or the needle may be slightly bent limiting flow past it ! You could try the other carb and see if that does the trick or go thru that one the only other thing I can think of at the moment is an exhaust flow restriction can also cause simmular conditions.

Gonna change to 20:1 Lucas Semi, Check for leaks, adjust carb accordingly and Ill post update. I ordered Jets also but they wont arrive till next week.
My slide needle is a tiny bit bent(very small bend at the bottom). I didn't think it would affect anything. How can i straighten it back out?

 

[Street Ryderz]

Gonna change to 20:1 Lucas Semi, Check for leaks, adjust carb accordingly and Ill post update. I ordered Jets also but they wont arrive till next week.
My slide needle is a tiny bit bent(very small bend at the bottom). I didn't think it would affect anything. How can i straighten it back out?

Yes even a slight bend has a big effect and it's hard to get it back to straight so again if you have another carb you could use the one from that or try to straighten the one in it by tapping the high point with theneedle on a good flat surface but remember that there is a tapper to the needle and you dont want to flat spot it any!

 

[micromaster22]

Yes even a slight bend has a big effect and it's hard to get it back to straight so again if you have another carb you could use the one from that or try to straighten the one in it by tapping the high point with theneedle on a good flat surface but remember that there is a tapper to the needle and you dont want to flat spot it any!

OK. I will do everything listed below and report any changes. I appreciate the help!

Change fuel/oil mix to 20:1 Lucas Semi
Check for air leaks
Straighten Needle
Adjust Carb
Grease clutch gears

Am I missing anything?

 

[Street Ryderz]

OK. I will do everything listed below and report any changes. I appreciate the help!

Change fuel/oil mix to 20:1 Lucas Semi
Check for air leaks
Straighten Needle
Adjust Carb
Grease clutch gears

Am I missing anything?

That sounds good you have it all!

 

[crassius]

when checking for leaks, check head bolts and case bolts too

the factory screw ups with the crank bolt were common quite some time ago (check all the threads here about it for when) - you may have a motor been sitting on shelf, so bolts might have stretched a bit

 

[micromaster22]

Few updates.

Switched to 20:1 Lucas semi synthetic (runs a little better and sounds less rough)
Used some Teflon tape on th intake manifold and underneath the carb clamp (significant power increase)
Greased up the clutch gear with some lithium grease (less noise)

Overall, the engine seems to be running better. I've got it up to roughly 38 mph. I've ordered some jets and I'm waiting for them to arrive for better tuning.

However, I think there might be an air leak in the head. If I look at the head from the side I can see light from the other side. Once I take the 4 head bolts off and look at the bottom of the top piece, it doesn't seem to be flush against the other part.

Any suggestions?

 

[crassius]

if you have steel intake, then you might need to file the end at 45degree angle a bit to take uneven chrome spots off

head gasket is supposed to have gaps

 

[Street Ryderz]

Few updates.

Switched to 20:1 Lucas semi synthetic (runs a little better and sounds less rough)
Used some Teflon tape on th intake manifold and underneath the carb clamp (significant power increase)
Greased up the clutch gear with some lithium grease (less noise)

Overall, the engine seems to be running better. I've got it up to roughly 38 mph. I've ordered some jets and I'm waiting for them to arrive for better tuning.

However, I think there might be an air leak in the head. If I look at the head from the side I can see light from the other side. Once I take the 4 head bolts off and look at the bottom of the top piece, it doesn't seem to be flush against the other part.

Any suggestions?

If it now maintains a good idle and is producing power cleanly thru out the rpm range it's unlikely there is a head gasket leak!The easy way to tell is start the engine and put your hand all around the cylinder and head seal and see if you can feel pulses of air!

 

[micromaster22]

I can feel hot air on my knees and I swear sometimes my leg feels wet. Its also leaking slightly from the spark plugs hole.