tanaka/hitachi CS40ea rebuild.

[TBS]

I just acquired this saw from a fellow A.S. member, it needs a piston and muffler but it takes 15-21 days for parts to ship from tanaka and the piston may be NLA. I've got a piston from the earthquake that I will try, the jug looks fine but will need some clean up. This saw has a split case in plastic chassis.

 

[Chris-PA]

You gotta post some pictures - I like to see something different! Does that have the "Pure Fire" engine with the strange transfer routing? Removable transfer covers?

 

[TBS]

That's exactly what it has. I'll post some pictures soon as I can. I may have to go the dealer down the street from me since they deal tanaka. I'm not to fond of the head tech there since he refused to sell my employer hexagonal chain files.

 

[TBS]

Kegerator5 has a nice ported g621 for sale on fleabay.

 

[TBS]

There's a lot of different things on this saw.
That bar nuts are 1/2 inch(?). All the plastics are held on with Phillips screws.

 

[Kegerator5]

Hope you don't mind. Just commenting to follow along.

 

[Chris-PA]

I wonder if they could have made that exhaust port a little smaller?

 

[Kegerator5]

Chris, you should join him. I have a tanaka TCS33EB at home lol... I took it in being told it needs a carb. Current one gummed up.

I had actually forgotten about this saw until last night when I had to grab the homelite C-5 off the shelf to snap some pictures for another member. It was there on the "project shelf" with it lol.

I'm just too busy with fixing the house up to mess with any project saws here lately.. So I've been selling some of them off rather than letting them sit. Plus, selling the projects, and sum of the rarely used saws, helps fund the fixing of the house lol.

 

[Chris-PA]

Chris, you should join him. I have a tanaka TCS33EB at home lol... I took it in being told it needs a carb. Current one gummed up.

I had actually forgotten about this saw until last night when I had to grab the homelite C-5 off the shelf to snap some pictures for another member. It was there on the "project shelf" with it lol.

I'm just too busy with fixing the house up to mess with any project saws here lately.. So I've been selling some of them off rather than letting them sit. Plus, selling the projects, and sum of the rarely used saws, helps fund the fixing of the house lol.

Nah - at one time I thought they looked interesting, but then I looked into what Pure Fire was. It's basically an exhaust delayed scavenging scheme which relies on exhaust back pressure to work. You can certainly remove the exhaust restriction and change the port timing to turn it into a more conventional engine, but I've already experimented with that on another saw. Also, I have enough 40cc saws!

I am interested to see how the transfer porting is done on these though, as Tanaka made more radical changes to enhance the exhaust delayed scavenging effect than anyone else.

 

[TBS]

The transfers are interesting split all the way into the case. A lot of screws to remove to get the engine out of the chassis with part of it wrapping over the case so the flywheel has to be removed.

 

[nenicu]

I need a side picture of the piston and a pic of the intake boot. I think that the 45 cc mutt i posted in the Earthquake thread is copied after this cylinder. What's the bore of the cylinder. The mutt is 42,5 mm. Thanks.

 

[TBS]

Cylinder is 41.2 mm from my measurements.

 

[Conquistador3]

Nathan, that saw is still sold here in Europe, the only difference being it's orange instead of green.
Tomorrow I have to go to the local Hitachi dealership to pick up some parts and I will ask them if parts for this saw are easy to get or made of hen teeth.

 

[Chris-PA]

Interesting - it is actually not as radical as was shown in the animation I once watched. That might have been for a string trimmer or something. This looks like it could be made to breather pretty well.

 

[Chris-PA]

The upper transfers are very similar to the uppers in the GZ4000 and should flow well. They've extended the transfer runners all the way down to the bearings, much like with the Poulan clamshells. I would assume this was to get longer transfer runners to allow for more exhaust gas to be pulled in and a longer delay of the fresh charge entering the cylinder. I would bet it has a shortish blowdown angle but would be interested to find out for sure.

If you open up the muffler and porting I bet you can make it run quite well - you'll get good velocity through those transfers. Here was my experiment with a similar concept, but it didn't have anything like as nice transfers (it still runs very well): http://www.arboristsite.com/community/threads/exhaust-delayed-scavenging.292902/

 

[Conquistador3]

Before I forget... I went to the Hitachi dealership this morning.
All parts for the CS40EA are still available from Hitachi, but... engine parts usually take three weeks to ship and they aren't cheap: the piston alone retails for €49.90. They may shave off a little bit but that gives a general idea.
As these saws can be had brand new for under €300 in brick and mortar shops, I don't know how much sense it makes to fix a seized engine.

 

[TBS]

I did a little test fitting today and with a little grinding on the skirts the earthquake piston will work and give a nice bump for compression.

 

[nenicu]

You should make shure that the piston is not too small. The 40cc Eartquake is 40,5 mm[ I have a other 40 cc copy] .

 

[TBS]

I did a test fit yesterday and it seemed to fit fine but I'm going to double check.

 

[nenicu]

I know you can't believe sans proove but this is my saw stock: 40cc clone, 44 cc Homelite[strato Ryobi], 40cc strato clone[in pieces], 45 cc clone[ Eartquake style], 38cc clone[39,5 strato cylinder and normal piston],Partner 500,Partner 540,Partner 465, Partner 495x2, McCulloch 543,McCulloch Titan 70, Shindaiwa 490, Zenoah Komatsu g621, Zenoah Komatsu g2000[top handle], Zenoah Komatsu GZ 7000, Husqvarna 268. On the way from Ebay.de : Tanaka 5601 and Makita 4301. Gone :Ryobi strato 40cc x 2, 37 cc clone 2 ring piston.