dissecting an earthquake chainsaw

[Chris-PA]

Where did you find the oil leaks, and what does it take to fix them. 3 out of 4 of mine are leaking oil, I just haven't had the time to look into it yet.

There were two. One was where the outlet line attaches to the bar mount area. The original Redmax design seemed to have a better way to form the end of that line, and the one on the Earthquake clone looks to maybe have been melted or something. Anyway, I pulled the bar plate and muffler for access and cleaned up the surfaces with brake clean. Then I sealed in in there with Permatex Ultra.

The second leak was in the line from the tank to the pump. I pulled the (well made) fitting from the tank and all the fittings along the line, cleaned all of it with brake clean and found a tear in the line where it attached to the pump. The tank fitting is separate from the line so the line is easy to replace. I happened to have a nice line from a spare Ryobi tank so I used that, but I have no doubt one could be put together from standard line. I used Ultra to glue all the lines on.

I also have two GZ4000 saws with this same oil system design, one a real Zenoah/Redmax and one a Jenn Feng McCulloch clone. None of them leak at all.

 

[Lark-o]

I finally got around to baking the high temp POR15 on the muffler, turned out nice I think. Question... My muffler gasket is all tore up, Should I just use some high temp silicone or make a some kind of new gasket from some dead soft aluminum perhaps? It hasn't gotten above 7 deg in about a week, im starting to go stir crazy lol.

 

[Steve NW WI]

I finally got around to baking the high temp POR15 on the muffler, turned out nice I think. Question... My muffler gasket is all tore up, Should I just use some high temp silicone or make a some kind of new gasket from some dead soft aluminum perhaps? It hasn't gotten above 7 deg in about a week, im starting to go stir crazy lol.

I'm thinking a thin piece of copper would work best for an exhaust gasket, but I'm no pro.

I gotta get a new custom rect tube formed and welded at work, then I can finish my little exhaust project.

With the temps lately, I haven't even felt the urge to fire up the camera and make a stock video yet. I did file the stock chain though - couldn't see even bothering trying to cut with it as it came, and picked up a loop of 91VXL-62 at my friendly neighborhood Dolmar/Jred dealer. They're threatening us with close to 20° later in the week, maybe I'll venture out away from the stove then!

 

[Lark-o]

I'm thinking a thin piece of copper would work best for an exhaust gasket, but I'm no pro.

I gotta get a new custom rect tube formed and welded at work, then I can finish my little exhaust project.

With the temps lately, I haven't even felt the urge to fire up the camera and make a stock video yet. I did file the stock chain though - couldn't see even bothering trying to cut with it as it came, and picked up a loop of 91VXL-62 at my friendly neighborhood Dolmar/Jred dealer. They're threatening us with close to 20° later in the week, maybe I'll venture out away from the stove then!

I figured I wasn't the only one This weather had taken the fight out of . Carb kept freezing up on the snowblower the other day as I was trying to work my way to the back garage. I fought with that for a couple hours till I had a melt down and decided I was going on strike till warmer weather.

 

[NSMaple1]

OK - has anyone from Canada gotten one of these? Lately? And how did it work out? They won't answer my emails re. shipping to here. One of the listings had shipping charges estimated to here, but in the description it said lower 48 only.

 

[procarbine2k1]

I finally got around to baking the high temp POR15 on the muffler, turned out nice I think. Question... My muffler gasket is all tore up, Should I just use some high temp silicone or make a some kind of new gasket from some dead soft aluminum perhaps? It hasn't gotten above 7 deg in about a week, im starting to go stir crazy lol.

Permatex copper (I found it at Autozone) will do the trick for ya.. Aluminum would work too if you don't want to run to the parts store.

 

[procarbine2k1]

The timing is:

E = 151deg
I = 157deg
T = 110deg

Spark is advanced a couple of degrees. Also, I fixed the oil leaks and now it is dry as a bone sitting on the bench. Starts in 2-3 pulls every time.

Could you tell me what the stock numbers were on your saw by chance? Thank you in advance

 

[procarbine2k1]

I will be tearing in to one of mine this week hopefully! Had to get a saw buttoned up tonight (I don't like having more than one apart on the bench). I will check squish, and may end up doing a little machining on the jug, not sure yet. I do plan on a little port work, and a whole lot of work to the muffler. I could tell from the little bit of run time I had on mine, that there is a decent saw in there, but something needs to happen with that muffler (as many of you have pointed out). Seemed like there was a bath towel stuffed in there or something, probably the most restrictive muffler I have seen on a saw.
Maybe I can do a before and after, since I will be leaving one saw stock for the time being.

 

[Chris-PA]

I don't think I measured it stock, but maybe at one of the initial porting tries. Got a 102 fever ATM, so I will have to look later. My recollection is that it is quite restrictive.

They used the same approach as all the also-rans without strato. Restrictive porting, especially low volume high velocity transfers combined with a cat.

 

[procarbine2k1]

I don't think I measured it stock, but maybe at one of the initial porting tries. Got a 102 fever ATM, so I will have to look later. My recollection is that it is quite restrictive.

They used the same approach as all the also-rans without strato. Restrictive porting, especially low volume high velocity transfers combined with a cat.

Gotcha . 102 degrees, yowzers man hope you feel better soon!

 

[Chris-PA]

Thanks - it burned itself out for now. I didn't have a degree wheel before I did the first mods so I don't have the stock numbers. After the first mod it was:

E = 148deg
I = 147deg
T = 98deg

I had not touched the transfers (still tough without a right angle grinder) so those are stock. I had raised the exhaust just to the compression relief notch and dropped the intake, and widened both (they were very small - I think they are around 55% of the bore now). The squish is kind of 0.030" with the gasket removed, but there are some bumps in the combustion chamber so I'm not going further. Here is what the first round looked like as the old pictures are gone now:


For reference, here is an image I found on eBay of a Chinese clone of a G3800 cylinder. The transfers are much different:


The Earthquake runs very well and is a pleasure to use, but my GZ4000 still beats it handily. The GZ4000 has a similar muffler mod and only some blending and case matching of the lower transfers. Its numbers are:

E = 132deg
I = 137deg
I(S) = 165deg
T = 103deg

Lots of intake, short exhaust duration to preserve cylinder pressure, and a tiny blowdown because all that gets lost to scavenging is air. It's a good illustration of the difference between strato and trying to band-aide the old design, as that is exactly what the CS3816 is - what Zenoah would have had to do if they didn't develop strato.

 

[clemsonfor]

Anybody tested the compression on their 38cc? Mine only blew 135. Maybe I don't have a good seal? Gonna wet the boring and try again.

Retried it with moistened ring. And as tight as I can finger tighten. And got 145.

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[Yukon Stihl]

Anybody tested the compression on their 38cc? Mine only blew 135. Maybe I don't have a good seal? Gonna wet the boring and try again.

Retried it with moistened ring. And as tight as I can finger tighten. And got 145.

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By By base gasket

 

[trophyhunter]

By By base gasket

Yep, that would be interesting to see the difference in numbers for compression and squish before and after.

 

[naturelover]

Anybody tested the compression on their 38cc? Mine only blew 135. Maybe I don't have a good seal? Gonna wet the boring and try again.

Retried it with moistened ring. And as tight as I can finger tighten. And got 145.

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All four of mine were around that range...


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[Chris-PA]

Anybody tested the compression on their 38cc? Mine only blew 135. Maybe I don't have a good seal? Gonna wet the boring and try again.

Retried it with moistened ring. And as tight as I can finger tighten. And got 145.

Sent from my C5155 using Tapatalk

Don't worry about it. See that notch in the top of the exhaust port? Its job is to bleed off cylinder pressure at low speeds, so if it is working right then the static/low speed pressure readings should be low.

You can measure the squish height with soft small electronics solder. The gasket is about 0.020" and you need to have at least 0.020" gap. So if it is larger than 0.040" you can remove the gasket and increase the compression. You will need to seal the case with Yamabond or something similar. Mine is 0.030" without the gasket.

 

[clemsonfor]

Are you putting the solder in dabs on top of piston or fishing it through the plug hole like I saw on a diagram on the net. Kind of bend it and get it in the squish band and compress.?

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[Chris-PA]

I just twist the ends of some thin stuff and poke it through the spark plug hole.

 

[clemsonfor]

What size solder are you guys using? 1 or 2mm? I'm about to eBay some from china for a few dollars. I hate going to town rather just order it.

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[psjwi]

I don't know if photos have been already posted of the inside of the CS4116 muffler or even if they are all the same... but here is the inside of the one they sent me.

You can see the Catalytic material in the center baffle section. I removed this entire baffle and then opened the outlet quite a bit (not shown in this pic) But I found that I did not have the required welding skill to put this back together again and ended up taking it to a friend to weld back up. If I had to do it again - now that I know what's in there - I would probably just drill several holes through from the outlet side right through the baffle section and not have to bother with the hassle of welding it back together again.