Push lawn mower losing power with blade.

[StarTech]

Well since no one ask I will how was the engine prior to the servicing? This will help to determine if it the current problem was induced during the servicing of the engine or not.

 

[Drakensberg Lawn]

Well since no one ask I will how was the engine prior to the servicing? This will help to determine if it the current problem was induced during the servicing of the engine or not.

I have no idea. The client send us a few lawn mowers that was standing in a store room for a while and yust told us to fix as many of them that is possible.

 

[Drakensberg Lawn]

In image 091732 you can clearly see where the throttle cable was originally clamped to the throttle arm , about 1/4" from the free end
Higher up the throttle stop has been bent back and is not touching the throttle high speed adjusting bolt .
The triangle tab near the bolt ( top right ) should come around to contact the bent tang behind the throttle plate when the throttle control is at the lowers or stop positon.
The screw should hit the other side of the tang to limit the top speed.
When adjusted like this the spring connecting the throttle plate & the governor arm should be almost loose at minimum revs and around 1/2 as tight as shown in the photo at wide open throttle setting.

I tried what you said and nothing changed. My boss baught a new carburetor, he thaught it was the problem but still same problem.

 

[bertsmobile1]

I tried what you said and nothing changed. My boss baught a new carburetor, he thaught it was the problem but still same problem.

Then the governor is adjusted backwards.
When you put a load on the engine & it slows down the governor should relax and allow the throttle to open further
So when you have the blade on where is the throttle butterfly on the carb, open fully or closed ?
Without the blade it will happily run at fast idle , around 3000 rpm
When a load ( the blade ) is attached the throttle BUTTERFLY should be opened up further to compensate for the extra load so the engine is now running on the main jet not just the idle jet.

 

[Drakensberg Lawn]

Then the governor is adjusted backwards.
When you put a load on the engine & it slows down the governor should relax and allow the throttle to open further
So when you have the blade on where is the throttle butterfly on the carb, open fully or closed ?
Without the blade it will happily run at fast idle , around 3000 rpm
When a load ( the blade ) is attached the throttle BUTTERFLY should be opened up further to compensate for the extra load so the engine is now running on the main jet not just the idle jet.

It's fully open. I tried it fully open, half open and about less than a 1/4 open. Is it possible that if the shaft is not 100% straight that it can cause this problem? I took off the whole engin nowan saw that the shaft is a bit skew.

 

[Drakensberg Lawn]

Looks like the problem is with the engin itself. I put another engin on and it runs fine now.

 

[Gregac]

Are you sure that the baffle in the exhaust is clean. I had the same problem after 28 years of use. I found that the holes in baffle tube were completely plugged. At another time I found the point gap had closed to almost nothing, but that time it was accompanied by difficulty in starting.