Makita EA3601...the most intriguing saw to date?

[fordf150]

Figured out these were available so I ordered one to tear down and have a look. I saw the ipl last year and couldnt wrap my head around it so I had hoped holding the parts in my hands would help....it didnt!

Overall impression:

I love it, easy to tear down and work on. I had about 45 minutes in the complete tear down and reassembly of the saw and never once had to go to the service manual for guidance on how something came apart or went together. Very smooth controls and perfect alignment/fit/finish of all the pieces/parts. Seems well built with metal inserts in the plastic, lots of gusseting of the plastic housing in important stress areas. T27 fasteners for 99.9%, remaining fasteners were phillips head screws holding reeds and the reed plates so.

Outboard clutch for those that care but its a fairly clean and smooth clutch cover and case so chip flow should still be decent and clean up fairly pain free.

Lets start off with some general pics.

 

[fordf150]

Big air filter for a 36cc saw.

Strato is the bottom throttle bore...You'll see why I am having trouble understanding this saw later on and why i mention this now.

3 T27 screws hold the entire top cover on.

 

[fordf150]

Starter has the familiar "Easy Start" feature except it looks like they figured out how to shrink it down a bit because this saw doesnt have the bulging starter housing like all the other Makita/Dolly saws.

Picture of the flywheel shows the scoop on the back side of it for the air injection so air filters should stay nice and clean if it matches the performance of the 6100 air filter system.

 

[fordf150]

Muffler is held on with 4 bolts, one into the lower left corner of the muffler bolts to an extension on the crankcase. No cat and no SLR, just a standard old muffler with birdcage for a baffle, bad news is that its crimped together.

 

[fordf150]

4 bolts and the control bracket/air filter mounts comes off in one piece revealing separate boots for the intake and strato.

 

[fordf150]

removing the lower intake reveals the first set of reeds....yes I said first set.

 

[fordf150]

Adjustable metal oil pump bolted in. metal bumper spike, aluminum chain catch. Overall a pretty well built saw for the 30-40cc class of saws.

 

[fordf150]

I normally stop on a teardown of new models at this point because I use these as demo saws for a few months and sell them, nobody wants a 6 month old, 10 tank saw that has been torn down buuuuuuuuuuuuuuuuuuuuuuuuuuuut this saw just had me even more curious at this point so i kept going

 

[fordf150]

So here is what she looks like inside.

Nice looking cylinder with MAKITA proudly cast into it. Removable transfer covers. Sorry for the fuzzy pics, didnt realize they didnt come out very good until after the saw was back together.

 

[fordf150]

First pic is the crankcase side of the strato block that house reed set #1.


second set of reeds mounted to the engine crankcase

reeds removed on the crankcase reveals the entry into the crankcase

 

[fordf150]

complete case assembly with reed block installed.

 

[fordf150]

 

[BrokenSVT]

That looks pretty great, fellow Ohioan! Lots of features for a small saw.

 

[Sepia]

Wow great thread fordf150! That compression reading is something to behold. Great pics as well. That is a really nice looking little saw, and it looks well put together. I am curious why it has dual oil slots for the bar?

 

[Chris-PA]

Most interesting thing I've seen here in a while, thanks for posting it. I'd love to see a picture of the top of the case where the cylinder mounts.


It looks like the primary way into the transfers is through reeds. The two sets of reeds are set opposing each other, each feeding into the transfers. During intake/rising piston is pulls fuel/air into the case (no reed), and air through the first set of reeds into the transfer chambers. As the piston falls is pushes fuel/air through the second set of reeds into the transfers (first set of strato reeds are closed).

BUT - there must be some other connection between the case and the transfers, or it would not pull anything through the strato port at all, as the other reeds are closed then. From the diagram above it may be in the case under the exhaust port, although might just be a schematic diagram and not intended to be a physical representation.

Not sure what the advantage is to have both a reed path and a parallel open path between the case and the transfers?

EDIT: I suppose if the open transfer to case passage is small, when there is positive pressure in the transfers the reeds prevent that from blowing into the case. Would be interesting to know the port timing.

 

[Deleted member 149229]

I normally stop on a teardown of new models at this point because I use these as demo saws for a few months and sell them, nobody wants a 6 month old, 10 tank saw that has been torn down

I beg to differ, let me know when you're selling this in 6 months.

 

[fordf150]

I am curious why it has dual oil slots for the bar?

lower groove lines up with A041 and K041 bars. top slot matches up to K095 mount bars....not sure why. yet another intriguing design issue on this.

 

[fordf150]

Most interesting thing I've seen here in a while, thanks for posting it. I'd love to see a picture of the top of the case where the cylinder mounts.

View attachment 584026
It looks like the primary way into the transfers is through reeds. The two sets of reeds are set opposing each other, each feeding into the transfers. During intake/rising piston is pulls fuel/air into the case (no reed), and air through the first set of reeds into the transfer chambers. As the piston falls is pushes fuel/air through the second set of reeds into the transfers (first set of strato reeds are closed).

BUT - there must be some other connection between the case and the transfers, or it would not pull anything through the strato port at all, as the other reeds are closed then. From the diagram above it may be in the case under the exhaust port, although might just be a schematic diagram and not intended to be a physical representation.

Not sure what the advantage is to have both a reed path and a parallel open path between the case and the transfers?

EDIT: I suppose if the open transfer to case passage is small, when there is positive pressure in the transfers the reeds prevent that from blowing into the case. Would be interesting to know the port timing.

thats basically what i came up. of course i didnt take a picture of the case even though i easily spent a full 15 minutes staring at it and even brought it out to the counter so i could sit and contemplate how it all functioned.
I get a few minutes i may pop the cylinder back off to take some more detailed pics of it and the case mounting flange. It only takes a few minutes to do it. If i do i will tag you in it so your sure to see them.

 

[Sepia]

I also thought it odd that it had 2 rings on the piston, until I saw the compression reading, then it made perfect sense. An intriguing little saw, and pretty darn tempting as well.

 

[Tenderfoot]

Think Makita will ever make a 90cc version of their reed valve saws? Bet that would sell really well.