EF600 maximum AC output / governor opens throttle max. 1/2
i own a EF600 (german version / 230V - 50Hz) which I received as inoperable.
After cleaning the clogged carburetor completely like described in several articles here, replacing the oil-soaked air cleaner and refreshing oil and gas the EF600 starts and runs quite smooth.
The only 'problem' I noticed is that the EF600 will only deliver about 380 watts of power.
If I try to get around 400 watts the generators overload switch will disconnect after about 10 seconds (motor continues running).
Are 400 watts the maximum for this type of generator or should there be some more power available?
I don´t have any documentation about this machine.
The thing which confuses me is that even the generator is running under full load (400 watts) the governor opens the carburetor throttle butterfly only about 1/2, it never goes to 3/4 or full throttle.
Is this behaviour OK or is the governor malfunctioning?
Should it open up to the maximum by default if more power is drawn?
Re: EF600 maximum AC output / governor opens throttle max. 1/2
Gruenz, The governor arm (12) is not properly located on the governor shaft (9) that sticks out of the crankcase. There is a pinch bolt and nut (13) that tightens the clamping split portion of the governor arm that needs to be loosened to readjust the arm. To do that:
--Loosen that bolt/nut.
--With pliers, turn the governor shaft (9) CCW to it's internal stop (governor's internal weights (3) are fully collapsed).
--Move the throttle to fully open.
--Holding those 2 stop positions softly, tighten the clamp's nut/bolt.
--Recheck that the throttle goes fully open with light finger action (engine stopped).
--Readjust as necessary until it hits the carb's full throttle stop first.
A run check should show full throttle on a heavy load.
Also possible fact is that you are measuring 400W on one leg of the 230VAC, effectively reading only half of an actual 800W load.
I checked everything like described, the governor arm was properly fitted.
I figured out that the german version of EF600 will deliver only 400 Watts/ 500 Watts maximum (due to 50Hz and therefore lower rpm).
I rechecked and the machine runs now 480 Watts (lights/bulbs) without a problem.
The throttle is still open max. 1/3 but this seems OK.
As the original air filter element was no more usable I replaced it with a different foam element (not an genuine Yamaha part) which probably has higher airflow so the motor can breathe 'better'.
I guess that if airflow will degree (due to accumulating dirt) the throttle will open wider.
This seems to be intended in order to keep the machine running even with an dirty air filter element as it would be too much effort to clean the filter every 5 hrs...
BTW - I am impressed about the outstanding quality of this little Yamaha gem.
Its quite old and was not serviced properly in the past by the people who owned it before - after some cleaning and refreshing oil, spark plug and air filter it runs now flawless on the first pull.
I have recently purchased the ef600 as a non running project. I was given no history but it looks like it has sat for years as the pull cord was freely spinning.
I have spent the last few weeks reading and educating myself on this little portable generator. I have reached the limit of information available online. I have owned the Yamaha ef1000 for over 15 years and with very little use and routine maintenance it has Never had a problem. I have never rebuilt carbs or even attempted repairs on any type of engine. I was able to clean replace carb fuel lines and gaskets and even made a clean on the fuel pump. After changing the spark plug I now have an easy starting generator but only on choke. Gives good power and sounds healthy.
Here's the problem. The governor does not adjust engine speed when choke is taken off the engine surges to very high and then splutters and dies. I have checked for air leaks and potentially fuel pump but I think the problem lies with the governor. There's no movement on the governor. I can manually hold the governor and decrease choke and get a stable ish speed but again is very inconsistent. I could leave the choke on and it stays running (not great) for as long as I want but as soon as the choke is taken off it dies.
Any help would be appreciated. I have the tools, time and patience in my older age to disassemble the engine and determine the fault with the governor. This was the only post that give a reasonable description to the function of the governor and possible repairs.