dissecting an earthquake chainsaw

[Chris-PA]

Chris and Oz, I checked the compression twice with a screw in adapter on my gauge and then a third time with one with an adapter that has a rubber cone on it that goes against the spark plug hole, but, you both have me now questioning the seal between the gauge and the adapter. The two connect with a coupling like an air compressor quick connect. I will have to investigate that further. I hope to get some time to mess with it tomorrow, but our high temp forecast is for 26 degrees. We are not accustomed to many days like that here.

Chris and Stephen, i saw the ring in the pic also and had to go look again in person. It does not look that way in person. it still had oil residue on it from my wet test when I took that pic. The ring does move freely in the groove and ill have to check the gap. any idea what it should be?

Sadly, I never even tried to start it after checking the compression. It seemed ok when pulling on the rope but I wouldn't say it was overly strong feeling.

I may clean it and piece back together and see what happens.

Two questions:

1. anyone know the initial setting they started with after their jets were reinstalled? I forgot to count the turns.

2. Has anyone found a cheap and reliable parts source for these machines?

thanks for the help guys. I will post when I know more info.

I'm betting there is a problem with that compression reading and that it runs fine. On mine I removed the base gasket and sealed it with Yamabond, and still had 0.030" squish clearance. I don't have a compression gauge.

I don't remember the initial mixture screw settings - I usually go for 1-1/4 or so and just feel about from there.

 

[Ozhoo]

Am I smoking crack or do I recall something about the carb settings being way more open than normal? I could swear they were something like 2 1/4. I don't have a 3814 but I have a pair of 4518's that I can check.

 

[Chris-PA]

Am I smoking crack or do I recall something about the carb settings being way more open than normal? I could swear they were something like 2 1/4. I don't have a 3814 but I have a pair of 4518's that I can check.

You might be right about that. I am home today so I will check the settings of mine the next time I head out. The Gravely didn't want to start at 5deg so I'm giving it a bit more battery charge and will try again later.

 

[Chris-PA]

My L is at 1-1/2 and the H is at 1-1/4. It is ported and muffler modded but that should be ball-park.

 

[jteam]

well it is 25 degrees here today, but I did do some further investigation on my issues. I used my air compressor to test my compression gauge. Set the output pressure at 100 psi and give the compression gauge a blast of it. The gauge registered 110psi. I did this several times so I have eliminated the gauge. I cleaned the cylinder up good and did some further inspection and think I have found the issue. It was a bit difficult to get a good pic with my phone but Ill post what I got. The score in the pic is above the exhaust port and the deepest part is about 3/8" long (maybe a bit more) and it starts approx 1/4" below the very top of the cylinder wall.

I read much of this three year thread and i don't remember anyone getting one this bad. Looks like I may have gotten the first DOA. Open to suggestions. Thanks guys!

Side note: if i reassemble, where do you guys try to set the squish.... .020 +- ?

 

[jteam]

Thanks for the settings Chris!

I forgot to mention, I found small aluminum shavings on the roof of my cylinder that I was able to wipe out and see on my finger. Probably the root of the scoring.

 

[Chris-PA]

I don't think that is bad enough to account for those readings. I bet it runs fine.

Here's the thing - putting constant pressure from an air compressor into the gauge is not the same as a reading from a gauge on an engine. These are small displacement engines, so any additional volume you add to the combustion chamber - like removing the plug and adding some adaptors - will significantly reduce the compression pressure reached. Since the combustion chamber is so small it would not take much to have a big effect. Your air compressor has essentially infinite volume.

 

[naturelover]

See if it runs, if it does, it's got more than 50 psi....

Someone asked about the carb screw settings, iirc, mine was out near the 1-3/4 to 2 turn range on one of mine I think. Believe the others were within the 1-1/2 turn range though.


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[jteam]

Chris, I see your point, between the gauge and the adapter, there is a foot between the head and the gauge. I think I will just stick it back together and see what it does as you folks have suggested. It will be a few days before the verdict is in, because its back to work tomorrow for me and I did not put it together this afternoon because I have some JB drying on the muffler. I had some pin holes in my welding from the MM. I would have probably done more damage trying to weld them up. The 110 flux core blows holes in the muffler housing even on the lightest setting and trying to do small stitch welds. I can't wait to try it. I will definitely post back with my findings.

 

[naturelover]

Cool!

One of mine had a scratch on the cylinder too, but didn't make it to the rings. Believe it's the test mule, and it's been running quite well..

Where is the little check/Schraeder valve in your tester, it will have to be right at the end of the hose for the most accurate reading.


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[jteam]

Nature, that's good to hear. My test gauge has the release valve just below the gauge with the coupling and hose adapter between it and the test subject. It is one for vehicles but I've used it on mowers also, but never a 2 stroke before. I'm real curious how it will do for sure. I can't wait to get back on it! If it don't work, I'll hunt down parts. Thanks again.

 

[Chris-PA]

For any of you with the 45cc saws - what size venturi is in the carb on those things?

The ported saw will now keep up with a modified Homelite Super XL Auto 57cc. It also kept up with a ported Stihl 032AV.

If anyone sees the 58cc complete shortblock anywhere reasonable- please let me know. I'd like to get one and port it. The assemblies I've seen though do not come with a crank. If I can get a whole shortblock for $75 or so, I'm on it like white on rice and I will give porting a 58cc a try.

This is on ebay for
$61shippedView attachment 325915

I am curious about those 58cc saws, but I have a concern about carb size. They are based on the G5000, similar to the 45cc Quakes, but the G5000 had a Walbro WT series carb. They did not come with a venturi any bigger than 34/64", and that seems pretty small for 58cc.

 

[singinwoodwackr]

Am I smoking crack or do I recall something about the carb settings being way more open than normal? I could swear they were something like 2 1/4. I don't have a 3814 but I have a pair of 4518's that I can check.

that's what mine was

 

[Ozhoo]

that's what mine was

Thanks, It's reassuring that I wasn't smoking crack... hate when that happens

 

[jteam]

I haven't even unboxed my 4518 but was wondering if anyone has upgraded theirs to the 52cc or 58cc top end ? The kits look fairly cheap on the bay and a saw that size with 52 or 58 would be a screamer I bet.


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[Pallet Pete]

I haven't even unboxed my 4518 but was wondering if anyone has upgraded theirs to the 52cc or 58cc top end ? The kits look fairly cheap on the bay and a saw that size with 52 or 58 would be a screamer I bet.


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You have a link to those?

 

[MasterMech]

I haven't even unboxed my 4518 but was wondering if anyone has upgraded theirs to the 52cc or 58cc top end ? The kits look fairly cheap on the bay and a saw that size with 52 or 58 would be a screamer I bet.


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I haven't done the swap but I have a Chinese 52 cc saw and it rips right out of the box. A swap onto a 45cc quake would be very interesting indeed.

 

[milkman]

I haven't even unboxed my 4518 but was wondering if anyone has upgraded theirs to the 52cc or 58cc top end ? The kits look fairly cheap on the bay and a saw that size with 52 or 58 would be a screamer I bet.


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Would be fun to see a 5818 sleeper at one of the GTGs.

 

[DexterDay]

I haven't even unboxed my 4518 but was wondering if anyone has upgraded theirs to the 52cc or 58cc top end ? The kits look fairly cheap on the bay and a saw that size with 52 or 58 would be a screamer I bet.


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I will let you know

It's on the way!!

 

[Chris-PA]

The 58cc saws appear to have a longer stroke, but are otherwise the same. Also they are set up for 0.325" chain. Other than that they basically are the same saw as the 45cc quakes, so swapping the engine in would mostly be a matter of changing to different color plastic parts.

I'm not sure they would be screamers with the long stroke and probably fairly small carbs (for 58cc). They might make good torque though.