Murray "6HP" doesn't feel like 6HP??

[Kernal]

Murray "6HP" lawn mower doesn't feel like 6HP

I have a 15 year old Murray 6HP gasoline push mower which I've barely used in that period of time. Took it out today, cleaned the gas tank, put in fresh gas, cleaned the float bowl and the banjo bolt, took the spark plug out, it was good but sanded the tip, checked the oil, still very clean, added a cup more, sprayed some penetrating oil into the chamber, plug back in, started right up. Problem is that doesn't seem to have 6HP worth of power, but then I don't think it ever did. It also only has one speed due to the safety handle but the engine rpms fluctuate on it's own and it stalls easily, then it's hard to start back up.

Edit: might have the answer, I took the filter back out after running it an hour and the intake under the filter was wet with gasline so guess it's running too rich?? In the am will adjust the needle valve to see if that helps. Need to find a service manual for a Tecumseh lawn mower engine.

 

[Koffer]

I just got an old lawnmower my dad gave me .He bought new in 67 and got it running after a 20 year slumber .
Hit the youtubes as there is a ton of stuff on how to rebuild and tune tecumseh carbs
Sounds like theres still some crud in the carb

I have a 15 year old Murray 6HP gasoline push mower which I've barely used in that period of time. Took it out today, cleaned the gas tank, put in fresh gas, cleaned the float bowl and the banjo bolt, took the spark plug out, it was good but sanded the tip, checked the oil, still very clean, added a cup more, sprayed some penetrating oil into the chamber, plug back in, started right up. Problem is that doesn't seem to have 6HP worth of power, but then I don't think it ever did. It also only has one speed due to the safety handle but the engine rpms fluctuate on it's own and it stalls easily, then it's hard to start back up.

Edit: might have the answer, I took the filter back out after running it an hour and the intake under the filter was wet with gasline so guess it's running too rich?? In the am will adjust the needle valve to see if that helps. Need to find a service manual for a Tecumseh lawn mower engine.

 

[Kernal]

Ok, checked you_tubes, got some information. Sharpened the blade, cleaned the air filter, sprayed some carb cleaner into the intake while the engine was running (didn't take the carb apart). I need to check the spark plug gap (if I can find my gapping tool) and a new air filter but it runs better now. The motor still bogs down but I figure the grass is just too high and too thick for the motor size and the mulching mower design which traps the cut grass underneath instead of blowing it out. Need a bigger mower.

 

[D'Animal]

Check for a Mud Dabbers nest in the muffler.

 

[hkeller]

Old mowers had cast iron fly wheels that weighed a lot, new ones are plastic or cast aluminum. They don't have the inertia - power of the old heavy ones. Hence, they bog down faster.

 

[Kernal]

Bringing this back to update what I did to get more power from the lawnmower. It turned out to be the usual suspects; I first installed a new air filter then drained the old oil (which was still clean), added fresh oil (Rotella T6 I had laying around), poured SeaFoam into the air intake while the engine was running a dribble at a time. Added more SeaFoam to the gas tank a couple of times. I then installed a Champion EZ Start spark plug guaranteed to start on the first pull, and it does. With all that and a sharpened blade the mower now cuts better than ever.