Not Able to Make CS-501P Four-Stroke

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The Echo CS-501P I bought underwent a small modification today. I removed the little cross-shaped obstruction Echo put in the plastic carb intake thing. A guy who runs a dyno on Youtube claims this got him a tenth of a horsepower, so why not?

This saw has had maybe 4 tanks through it, and I removed a factory obstruction from the muffler as well as modding the intake, so I figured it was time to tune it. I used my ear and a Proline tach.

I tuned the saw according to the instructions I put together from various sources. I took the limiter caps off, warmed the saw up, set the idle so the chain started to creep, and used the tach and L screw to get the max RPM, which was 3820.

I slowed the chain down until it stopped, although I didn't make sure I was at 2700, the factory setting. I started adjusting the H screw.

I got 14,900 at first. The factory max is 13,800.

My understanding is that at this point, I was supposed to richen the mix until the saw misfired at WOT. I started loosening the H screw.

This worked with my other Echo, but this one never misfired. It just ran slower as I loosened the screw, going down into the 12,000's. I finally set it at 13,500 and went in the house.

Am I doing something wrong here?

Those limiter caps were a bear to get off, and the special tool I ordered to thread into them did not fit. I didn't know there was a plate pressed into the carb to hold them in. I threaded a wood screw into one, put the screw in a vise, and pulled like hell on the carb. Finally, the plate came off, and I realized it was the problem.

I had some new caps that weren't chewed up by a wood screw, so I removed the tabs using a bench grinder and installed them.

This saw seems to sling a ton of oil. Is it possible it's because it has a short bar that needs less oil? I am running a 16" bar because I want a light, nimble saw that's overpowered for its length. I had to blow out all sorts of grease-and-fines paste, and after I cleaned the saw with alcohol, I reduced the oil flow.

I thought this saw would be as simple to work on as my CS-590, but Echo put two different sizes of screws on the carb, which is annoying. Also, there are 4 washers on the carb screws, and at least two are proprietary. One fell into the saw when I took the intake off. I made a custom washer, and when I was tuning the saw, the original fell into the grass where I could pick it up.

There were dry fines all over the area under the air filter. It seems like some of the wood I cut generates more of this stuff than normal trees. A lot of the things I cut are really dry, because trees here are sickly. I saw an air filter add-on that allows the use of a bigger filter, and I thought it was stupid until I opened this saw up and saw all the crud. Now I may buy it.

I may open the muffler up more before long. I am considering trying to braze a little pipe onto it.
 
I just found out why the caps were hard to pull. I didn't know I was supposed to turn them so the tabs aligned with the little recesses in the plate. I was trying not to turn them much so they would be close to a setting where I knew the saw would start and run.
 
I just found out why the caps were hard to pull. I didn't know I was supposed to turn them so the tabs aligned with the little recesses in the plate. I was trying not to turn them much so they would be close to a setting where I knew the saw would start and run.

That is correct. The tools are left-hand threaded so that the left-hand rotation as you screw the tool into the cap puts the tab in alignment with the slot in the cover plate so it can be pulled out (the cap turns counter-clockwise until the tab stops it, and it is then in position to be removed). I don't know about the 501, but on most Echos I've fooled with you turn the left-hand cap into position and start it just slightly out of the hole BUT NOT PULL IT OUT YET, then you move to the right-hand cap and turn it left into position against the left-hand cap. The left-hand cap indexes the right-hand cap. Once you have both caps positioned correctly they should come out easily.
 
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