dissecting an earthquake chainsaw

[procarbine2k1]

Well, we've talked about it before and the general consensus was the 38 and 41 cc models were virtually identical to the G3800 Redmax design. There were a couple of differences here and there but nothing serious. Someone pointed out these designs started coming out of China shortly after Redmax stopped using the non-strato charged designs in favor of strato charging for better emissions and power.

Best we could tell, a number of Chinese manufacturers were copying the 40 cc non-strato engine with a few variations. They were passing emissions standards at the time by adding a lot of restriction to the muffler which heated the muffler and produced fewer emissions. Build quality was very inconsistent. The best stuff was coming out of the factory producing Earthquakes. They seemed to have better quality control than most of the other manufacturers.

I went so far as to buy some of the Zenoah engine parts (new, strato-charged stuff) and "upgrading" a couple of my little Quakes. Parts swapped without a problem and I made a couple of little sleeper saws. The crankcase is the same for the 38 / 40 / 41 cc saws. I also ordered a few parts for the Ryobi and Redmax saws which bolted right on to the Quakes.

Now, when we get to the 45cc version, it appears to be the same thing. However, I don't have a G5000 to check parts interchangeability. The G5000 would seem to be the basis for the 45 / 52 / 58 cc saws coming out of China now under several different names. Again, it would seem the plant making the Quakes is doing a better job than most of the others.

It all comes down to the question of what you're planning on doing with the saw. For me - I enjoyed opening the mufflers, opening the air intake, doing a little port work, and changing parts between strato and non-strato. It was fun, it was cheap, I learned some more about saws and got to sell one or two along the way. Would I buy one of these to depend on for my wood-cutting requirements in the future? No.

Would I buy six to try my hand at porting, muffler mods, bar and chain combos, timing changes, etc.? You betcha!

Is there ALWAYS a Quake in the bed of my truck, ready for action? Yes.

dd

Nice post!

If these are based on the Redmax G5000, they will be fantastic saws, even with just a decent build quality- and I wouldn't be surprised it they hold up to a fair share of abuse. For the price, I just don't see how a guy could go wrong. I have a couple projects to finish up, and plan on grabbing a couple of the 45cc quakes (for play more than anything else), and must say I am pretty optimistic! I normally have a 372 or a 550 in my hands, these saws aren't intended to fill their shoes, but may find their own place in the lineup, we will just have to see where it is.

 

[trophyhunter]

So if the Quaker 45cc is a Redmax 5000 design I wonder if it's possible to add a larger P&C to it? An increase to 58cc would be a riot, I love these things.

 

[dswensen]

Would I buy six to try my hand at porting, muffler mods, bar and chain combos, timing changes, etc.? You betcha!

Six huh? I only have five. I might need another one ..... (huge grin)...

 

[Steve NW WI]

So if the Quaker 45cc is a Redmax 5000 design I wonder if it's possible to add a larger P&C to it? An increase to 58cc would be a riot, I love these things.

I just got done looking at the G5000 IPL here: http://www.redmax.com/ddoc/RMXI/RMXI2008_USen/RMXI2008_USen_G5000AVS_SN608281 and up.pdf

There's a whole lot of similar going on there.

 

[trophyhunter]

I just got done looking at the G5000 IPL here: http://www.redmax.com/ddoc/RMXI/RMXI2008_USen/RMXI2008_USen_G5000AVS_SN608281 and up.pdf

There's a whole lot of similar going on there.

Yep, you nailed it. So now we know how to get parts for these, that just made them an even better deal.

 

[Steve NW WI]

Plus, they give a spark plug spec. RCJ6Y, that we can understand. Not sure where I'd cross reference the china special that came with the saw.

The Redmax shows a 2 piece muffler, at 31 for the muffler and 15 for the cover at one site, I ain't interested though.

 

[diggers_dad]

I just got done looking at the G5000 IPL here: http://www.redmax.com/ddoc/RMXI/RMXI2008_USen/RMXI2008_USen_G5000AVS_SN608281 and up.pdf

There's a whole lot of similar going on there.

Thanks for the link, I bookmarked it!

I'm no expert, but it looks like no more than 3 or 4 changes to the original design. One thing I ran into on the smaller saws was a difference in the diameter of the crank shaft. The Chinese imports had a slightly smaller diameter than the actual Zenoah. IIRC, the flywheel would change but the threads on the clutch were a little smaller on the Chinese saw.

 

[Steve NW WI]

Speaking of the clutch, I'm having a heck of a time trying to get mine off. Looks to be marked LH thread, but I'm getting nowhere trying to budge it. Really want to investigate the oil leak mine's got.

Suggestions? Maybe I'll make a clutch tool that'll adapt to an impact if all else fails. Right now, I'm just using a brass drift punch and hammer (with a piston stop installed).

 

[trophyhunter]

Plus, they give a spark plug spec. RCJ6Y, that we can understand. Not sure where I'd cross reference the china special that came with the saw.

The Redmax shows a 2 piece muffler, at 31 for the muffler and 15 for the cover at one site, I ain't interested though.

Looking at that muffler on their schematic I don't see anything that looks like EPA add-ons, essentially an empty vessel with only a spark screen. I might try and pick one of those up and compare it to the one I modded for performance.

 

[trophyhunter]

Speaking of the clutch, I'm having a heck of a time trying to get mine off. Looks to be marked LH thread, but I'm getting nowhere trying to budge it. Really want to investigate the oil leak mine's got.

Suggestions? Maybe I'll make a clutch tool that'll adapt to an impact if all else fails. Right now, I'm just using a brass drift punch and hammer (with a piston stop installed).

Don't sweat that clutch just yet, if you look down into the oil tank with a flashlight on the 45cc units you'll see the hose has a filter on the pick up end and it has a sealing grommet molded into the line as it passes through the casting and attaches to the oil pump. Basically I thought all of mine were "leaking", but after some investigating they all were all set full out on the adjustment. Pull the clutch cover/brake, bar and chain and just start and run the saw with the oiler all the way out and watch how much oil that saw pumps out the oiler slot when you bring up the RPM's.

They need to be dialed back or there's just way to much residual oil left after you shut the saw off. My 576's don't oil that well...

 

[tilenick]

I just bought me two of the 45cc models last night. They will go well with the 38cc I bought when this thread was new. So fun

 

[diggers_dad]

Speaking of the clutch, I'm having a heck of a time trying to get mine off. Looks to be marked LH thread, but I'm getting nowhere trying to budge it. Really want to investigate the oil leak mine's got.

Suggestions? Maybe I'll make a clutch tool that'll adapt to an impact if all else fails. Right now, I'm just using a brass drift punch and hammer (with a piston stop installed).

When I first started working on saws I bought a clutch removal tool, like the one on the left. Later, one of the guys here said they used old sockets with material ground away to make the tool. Now, instead of $8.95 + shipping for a removal tool, I pay 50 cents each at a local pawn shop and grind it down to suit my needs. I keep several old sockets on hand in various sizes for whatever comes up. The one on the right fits the Earthquake clutch.

The threads are LEFT hand. I have never seen a saw with right hand threads on a clutch.

Caution: When using a piston stop, be careful. I (and others here) have caved in the top of a piston using a metal piston stop. The plastic piston stops work pretty well, but when I want to prevent movement in the piston I generally use a piece of starter rope threaded through the spark plug hole. It isn't as fast but removes the danger of damage to the piston.

 

[diggers_dad]

Looking at that muffler on their schematic I don't see anything that looks like EPA add-ons, essentially an empty vessel with only a spark screen. I might try and pick one of those up and compare it to the one I modded for performance.

IF I understand the idea behind the emissions requirements (and that's a big "if"), Redmax met the requirements for fewer emissions by bringing more air into the combustion process. They called it "Strato-charged". At the same time they discovered it produced more power and used less fuel. The down side was it ran very close to being too lean. That's why so many people complained about the initial tune on new saws and all the mess with hi and low screws having limiters.

Once Redmax had an improved design that made more power and met requirements they were off to the market. The Chinese now have a solid (but out-dated) design that doesn't meet emission requirements. They had to figure out a way to burn the fuel more completely and do it on the cheap. The easiest way to burn off contaminants is to increase the heat. Increase the heat by adding material in the muffler and restricting it. It was a cheap fix and did what they needed.

So, in the end Redmax gets a new and improved design. The Chinese get a solid design and make some changes to use it in the US market. Redmax has a lighter and more open muffler. The Quake uses a heavier and more restrictive muffler. The Quake is a dog right out of the box and is no threat to most saws on the US market. But, for those of us who know how to do a "muffler mod", the sky is the limit!

 

[Lark-o]

When my 45 cc Quake showed up the first thing I did was check everything out and started modding before I even ran it. The muffler was given a second, larger port and both ports were given removable spark screens. I don't like the bright red chain brake flag so I swapped it out with the brake flag from a Ryobi 40 cc saw. It took a little adapting but worked out well. Next up was the chain adjuster. I removed the stock setup and replaced it with one that can be adjusted from the side of the saw instead of the front. The side tension adjuster was also from the little Ryobi.

I didn't want to use the 3/8ths rim so I dug around and found a .325-7 rim and appropriate 16" bar. The only chain I had was .325 chisel safety chain but it was new and sharp. After all the mods were finished I fueled and oiled the saw and headed for the wood pile.

Even with the safety chain (which wouldn't allow me to get a full bite) the little saw was impressive. It easily cut as well as any stock 50 cc saw I have ever ran. The anti-vibe was good and I had to back the oiler off a little because it was slinging so much oil. Just to see where it settled in after I had tuned it in the cut, I put the tach on it for some readings.

Idle: 3,400 rpm
WOT in the cut: 10,100 rpm
WOT no load: 13,900 rpm

Overall, I'm happy with the little saw. Would I be willing to pay $150 plus for a saw like this and have to mod it? Nope.
But for $48.40 for the saw, a few bucks for extra parts and a couple hours shop time I think it's a bargain.

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I like that chain brake! This massive red thing is gawdy and tacky. what ryobi did you take that off of?

 

[trophyhunter]

The red hand brake does look like something that should be pouring itself out of a clown car. I cut two cords with the Quake I muff modded today, darn thing is a neat little saw and it handles well and there's just enough weight to let it self feed in bigger cuts.

 

[diggers_dad]

I like that chain brake! This massive red thing is gawdy and tacky. what ryobi did you take that off of?

That is from the Ryobi 40 cc saw with the Zenoah engine. They've been out of production for a while and it's getting easier to find them at garage sales really cheap.



The same saw with different plastics was sold as Craftsman, Ryobi, McCulloch, and a couple of others. The change over is not a direct replacement; you have to remove some of the plastic here and there to make everything fit and function. If you go slow and look at how they work it's not too bad.

 

[diggers_dad]

The red hand brake does look like something that should be pouring itself out of a clown car. I cut two cords with the Quake I muff modded today, darn thing is a neat little saw and it handles well and there's just enough weight to let it self feed in bigger cuts.

Yup.

I removed the safety bumpers on the 325 chisel chain I'm running on mine, effectively making safety chain into what my oldest boy calls "danger chain." It still has the standard rakers on it so I guess it's close to non-safety chain. Anyway, after that I took it out for a few cuts. It was kinda fun to run so I would up noodling a whole bunch of wood just to get the feel of the saw. As trophyhunter pointed out, it's enjoyable to operate. Light enough to not cause a backache and big enough to do some serious cutting. I consistently buried the 16" bar as I was noodling and the saw never missed a lick. Before I realized it I had went through three tanks of fuel and bar oil.

Speaking of bar oil - this thing puts out oil like the Exxon Valdez. Wow. I wish a few of my Stihls had an oiler like that. With a 16" bar buried you would think I would have the oiler maxxed out. Nope, it's somewhere between 1/2 and 3/4 capacity. Nice.

dd

 

[Scoutillac]

#3 quaker came today. No bar, file, or wrench in the box I am not happy I got screwed out of a bar, maybe they will make it right.

 

[Brian B.]

Ok, now that's some BS, it is supposed to be a complete saw, as a minimum.... They need to remedy that, that's some bull.

 

[gottagetsawz]

#3 quaker came today. No bar, file, or wrench in the box I am not happy I got screwed out of a bar, maybe they will make it right.

When one if my saws was missing the bar and cover I ordered another saw and sent a note with the order about missing them and if they could send an extra one with this saw, when the next saw came,no xtra bar or cover, BUT the next day fed ex dropped off another box with the bar and cover,so yes they do try to make things right