weird problem!

[orthobird]

Can anyone diagnose this problem?


This is a brand new 60 cc motor, gas, 2 stroke.
flips easily to start:
choke on, flip 4 times, it pops.
take choke off, flip 4 times, and it runs.
Idles very well.


Ok, if i try to get above 5500 rpm, motor wants to shut down. like it is starving.

so i changed needle settings, changed timing, you name it!

still no improvement.
I put everything back to factory settings, and ran it again, once i get to 1/3 throttle, it reaches 5500 rpm. then wants to shut down, and if i do not decrease throttle, it will turn off.


SO then, i did this:


i put half choke on

and WOW< it came alive!!


ran awesome and got full throttle!

I ran it throttle wide open (with half choke on), and got 6600 rpm, but the moment choke is completely removed (meaning, choke is completely off), it (the motor) shuts down!!!


what could that be?

 

[jon595]

You have an air leak. It is lean. The choke richens it up so the rpms go up. Fix the problem before you run it again.

 

[orthobird]

Air leak where?

Between the carb and reed block or somewhere like that?

 

[49dimes]

To validate that leak spray some carb cleaner at the reed block while it idles. the engine will immediately die if it is leaking.

 

[orthobird]

Anyone have a schematic on how the gaskets for the Walbro carb & reed block are positioned and placed?

 

[jamesrxx951]

Make sure the carb pulse port is lined up properly. The engine may have enough pull on fuel with the rpms lower but cannot sustain at high rpm.

 

[49dimes]

Just take a picture when you pull it apart .

 

[orthobird]

OK, here it is:

 

[49dimes]

OK @orthobird LoL! A moldy cheese thread has been started in the engine forum on it.

 

[49dimes]

Just so you know......They copied a beloved competitor on the reed block. Looking at the break down they do not show an O ring that gets installed on the one bolt hole next to the pulse port hole in the carb plate which is part #6037.