Tuning a Ported Saw Question - Ported Makita

[Gvsu141]

I have a t4Driller ported Makita ea5001p (Dolmar 5105). Saw has a limited coil. I have no experience tuning a saw like this, and am looking for some tips. This thing has a full on port job, milled/decked, etc. Pushing over 200psi.

Saw had some carb issues from sitting (needle was stuck open) - so I went through the carb, all set there now. Metering lever was set a bit low, so raised that back to spec. Got the low end all set and tuned like normal. This is one snappy little saw! I was debating on selling it, but I might need to hold onto this thing.

My question comes into tuning the high end, particularly since it has a limited coil. I can't get it to 4 stroke like normal due to hitting the limiter. I have a TT-20k wireless tach, but keep running into the rev limiter when trying to tune. It also seems the limiter is messing with the tach readings, so can't get a solid read there.

When I got it, the H screw was set about 2.5 turns out. Though I did raise the metering lever as mentioned. I know I need to get this tuned in the wood. Any tips with the limited coil how to do this? I'm expecting to hit the limiter again as soon as I lift out of the cut.

1. Set the saw pig rich, so it 4 strokes well under the rev limiter threshold.
2. Begin to slowly lean it out in the cut.
a. What's the best way to do this? Esp. since I'm not expecting to tell by lifting in the cut
b. Do I tune for max possible RPM in the cut per my tach? Or slightly fatter than max?
c. Some other process?

Thanks in advance

 

[cuinrearview]

Don't lift the saw chain completely away from the work. You can vary the load on the saw and the sound/rpm produced without going all or nothing.

 

[Gvsu141]

Here's some videos I just made cutting in 10" Ash log, Each video has one full cut, then one where I varied the pressure and lifting. I'd like to optimize this saw, but still be safe. How do any of these sound?

At 2.5 turns out on the high screw, there was a slight 4 stroke and occasional gurgle in the cut. I didn't video this. I leaned it out by 1/4 turn each video.

2.25 turns out: no 4 stroke.

2.0 turns out: Cut a bit faster. Higher RPM in cut

1.75 turns out: About the same cut time as 2.0 turns out, but higher RPM.

 

[Nutball]

I'll get my saws tuned close enough in a few minutes, but I like to tweak them over 2-3 tanks of gas to really get them dialed in right.

 

[huskihl]

Here's some videos I just made cutting in 10" Ash log, Each video has one full cut, then one where I varied the pressure and lifting. I'd like to optimize this saw, but still be safe. How do any of these sound?

At 2.5 turns out on the high screw, there was a slight 4 stroke and occasional gurgle in the cut. I didn't video this. I leaned it out by 1/4 turn each video.

2.25 turns out: no 4 stroke.

2.0 turns out: Cut a bit faster. Higher RPM in cut

1.75 turns out: About the same cut time as 2.0 turns out, but higher RPM.

Your last sentence pretty much tells you what you’re looking for. At 1.75 turns you’re making a little bit more RPMs, but you’re probably giving up some torque. RPM is varying up and down more. I would spin it back to 2 turns out and put a tank of fuel through it and then check the spark plug color

 

[Catfishclark89]

I like the look and sound of 2 turns

 

[Gvsu141]

Your last sentence pretty much tells you what you’re looking for. At 1.75 turns you’re making a little bit more RPMs, but you’re probably giving up some torque. RPM is varying up and down more. I would spin it back to 2 turns out and put a tank of fuel through it and then check the spark plug color

Ok perfect thanks for the info, the RPM is a good point. Always learning! 2.0 turns is where I ended up leaving it for now. Good idea about the plug, I'll throw a fresh one in and monitor.

I like the look and sound of 2 turns

Thanks for the confirmation. Good to know I was thinking somewhat right. This limited coil was throwing me for a loop.


On a side note - this saw is awesome. I finished up the firewood pile using my 2252 Jonsered (Husky 545) with a muffler mod. I thought that was a nice saw, but this Makita is on another level! Approx. 40% faster cut time on this small-medium size wood.

 

[davidwyby]

I like it so it wavers in and out with just the weight of the saw.

*Do Not one hand a saw with the bar tip in the log…trim log as in vid.