Chainsaw Repair
Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => RedMax => Topic started by: Cut4fun . on March 29, 2011, 02:04:38 pm
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Interesting - and unfortunate - about that missing A/V mount. I know on my clone that when I tore that mount the saw was much more floppy. It was quite obvious. I hope it's not a problem on yours.
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More
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Today i assembled my Zenoah Komatsu G621 avs. I think is an older model because on the right side has only 2 av mounts.
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The Zenoah gasket was just like the isolator. A big restriction from the factory.I did a little porting on the cylinder,but working with a chain file is slow. And you don't get the same results like the defunct dremel.
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On the right side is the original Zenoah isolator.The clone is larger at the cylinder.
I understand now - my clone is like the one you show on the left, and I never saw the Zenoah original.
I did not take any pictures of the isolator, but you can see the shape of the opening on the gasket.
(https://chainsawrepair.createaforum.com/proxy.php?request=http%3A%2F%2Fchainsawrepair.createaforum.com%2Findex.php%3Faction%3Ddlattach%3Btopic%3D197.0%3Battach%3D16425%3Bimage&hash=414c4569e68a937d82ff55f1697ab291676b9f68)
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Zenoah clone carb on the right, on the left Walbro 195 [ W 199 has the same linkage]. I'm thinking at installing a Husqvarna 372 air filter sistem[the bolt holes are level]. I have to find a way to attach the air filter cover.
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On the right side is the original Zenoah isolator.The clone is larger at the cylinder. If you look at my pictures you will see that my 72 cc clone has now fast idle on the choke button. It has an aftermarket H 365 carb.I think that with a little work a H 357 carb [Walbro 199] can be made to work keeping the fast idle on the choke.
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Today i got some parts for my Redmax 621. Gasket set[for a 62 cc China clone] and a carb isolator. The case gasket is a perfect fit, the isolator is a little diferent.Seems that the 62 cc clones are copied exactly, and the 72 cc clones are on bigger cases.
Which one is which in your pictures? The one on the left looks like what I remember from my 62cc, but of course it is assembled now.
Recently some versions of what is sold elsewhere as the Topsun T6220 came up on eBay here at a very good price, and with some better pictures. They have clearly changed all the plastics, and the top cover design looks like an improvement. I could not see the air filter arrangement but the G621 original could stand some improvement. Also the high idle throttle lock button was gone, so I assume it must have a carb with a more conventional integrated high idle/choke linkage, which would also be an improvement.
I'm curious about them and what other changes were made, but ironically the revised parts kept me from buying even if they are improvements. There would be zero sources of spare parts here, whereas with my G621 clone I've got at least some chance of finding used Zenoah parts.
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Today i got some parts for my Redmax 621. Gasket set[for a 62 cc China clone] and a carb isolator. The case gasket is a perfect fit, the isolator is a little diferent.Seems that the 62 cc clones are copied exactly, and the 72 cc clones are on bigger cases.
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I finaly cut with the 72 cc clone. Green locust. It seems close in power with a Husky 268 open port i have.18 inch bar ,325 chain versus 20 inch 3/8 chain.
I'd like to have one of the 72cc versions, but they don't show up here.
I ran my 62cc clone yesterday, and it fired up in a couple of pulls as usual even though it's been sitting for a while. It's really a joy with a 20" bar and balances well.
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I finaly cut with the 72 cc clone. Green locust. It seems close in power with a Husky 268 open port i have.18 inch bar ,325 chain versus 20 inch 3/8 chain.
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I still have to put that in some wood. I have also a 62 cc Zenoah clone that is based on the G 450 case .That one has a 48 mm cylinder and 34 mm stroke. The carb venturi is bigger compared with the 50 cc carbs. Today i was messing with a 50 cc carb and comparing with a Walbro 109[Partner 500 carb] the venturi size is the same. Seems that the bigger venturi on the 62 cc clone is ok. Afirmativ on the bolt spacing, but i was comparing a 72 cc clone with 62 Zenoah[Redmax]. Clone vs original.
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Oh I see - I think I do recall you saying you added that impulse port but I misunderstood. So from the factory the difference between the 62 and 72cc cases is that they used a larger spacing on the cylinder bolt pattern?
The agree the carb is marginally sized for 62cc. Yet they sell the saws based on the G5000 in displacements up to 62cc as well - and that has a carb based on the WT series which can't get even that big!
I bet your 72cc runs very well with the larger carb.
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The work on the piston is similar with the design of a Partner 100 piston[factory]. For my Redmax 621 i'm looking for a Walbro 199. With a Walbro 164 you have to drill the impulse from the back of the carb[they have a little mark there so is not a big problem], and you can use the original cover.Here the HDA 164 is very rare so a HDA 199 from H 359 is easier to find.
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Greencut gs 7200. The original carb setup was a exact replica of a Redmax g 621, even the venturi size[15,08]. This is small for 60 cc, for 70 cc is smaller. So whats in the pictures is my doing. I drilled a hole in the case for a impulse port, made a new trottle rod [modified from 50 cc Zenoah clone], enlarged a bit the intake block and filter holder.The carb is a chinese carb for Husky 365-372.I had to drill a hole for the trottle rod on the right side . I now have fast idle on the choke button.
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The rest is on Arboristsite.
I left you a message over there but I stopped posting on AS.
I'm wondering if something like an HDA-164 would be easier to mod? It's larger than the stock carb and has linkages in the same location, but it requires an impulse tube through the top cover which won't fit well.
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The rest is on Arboristsite.
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The carb is for a Husqvarna 372. Comparing by eye only the venturi is larger[18-18,5]. The original Walbro HD 12 venturi is 17,46. I think the chinese is larger.
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Is that Chinese carb based on an HDA? How large is the venturi?
I keep thinking about adapting a larger carb but the darn thing runs so nice as it is I'm having a hard time justifying the effort. I guess there is such a thing as "good enough"!
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Second
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Redmax
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The 72 cc clone carb seems to have the same venturi like the Redmax carb 15,8-16 mm. I'm now looking to install a H 372 carb[China]. It needs boring theintake manifold and filter holder. A little hole to hook-up the accel rod and an external pulse.
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Yes, given the numbers on Acre's site I had no idea what to expect. I weighed it on the digital scale at work when it came in, and was very happy with 12.4lb PHO. There are few 62cc saws that can match that. I really like using it.
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Found this weight 12.5lbs on redmax power equipment link. http://www.redmax.com/files/Zenoah/RedMax/catalog.pdf
G621AVS 62.0 3.8 2-Stroke 4.1 12.5lb
redmax 621 G621AVS IPL http://www.redmax.com/ddoc/RMXI/RMXI2008_USen/RMXI2008_USen_G621AVS_SN642078%20and%20up.pdf
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Acres shows it being a heavy bugger. http://www.acresinternet.com/cscc.nsf/ed1d619968136da688256af40002b8f7/e37b2b8e095847de88256d0a000b0b6a?OpenDocument
Retail cost and years sold close? 89-99
G621AVS 1999 $660.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 16
G621AVS 1999 $665.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 18
G621AVS 1999 $670.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 20
G621AVS 1999 $675.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 24
G621AVS 1998 $660.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 16
G621AVS 1998 $665.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 18
G621AVS 1998 $670.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 20
G621AVS 1998 $675.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 24
G621AVS 1997 $660.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 16
G621AVS 1997 $665.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 18
G621AVS 1997 $670.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 20
G621AVS 1997 $675.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 24
G621AVS 1996 $660.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 16
G621AVS 1996 $665.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 18
G621AVS 1996 $670.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 20
G621AVS 1996 $675.00
Engine Make: Zenoah
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 14.9
Bar Oiler Type: Automatic
Bar Length: 24
G621AVS 1992 $560.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 16
G621AVS 1992 $565.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 18
G621AVS 1992 $570.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 20
G621AVS 1992 $575.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 24
G621AVS 1991 $545.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 16
G621AVS 1991 $550.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 18
G621AVS 1991 $555.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 20
G621AVS 1991 $560.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 24
G621AVS 1990 $545.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 16
G621AVS 1990 $550.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 18
G621AVS 1990 $555.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 20
G621AVS 1990 $560.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 11.9
Bar Oiler Type: Automatic
Bar Length: 24
G621AVS 1989 $505.00
Engine Make: Komatsu
Engine Size Cubic Centimeters: 62
Engine Size Cubic Inches: 3.78
Dry Weight: 12
Bar Oiler Type: Automatic
Bar Length: 20
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The real thing[Redmax] is in pieces . From what i remember it was significant ligther compared to the clone[20 bar Redmax vs 22 Clone].Edt: i think 5kg .
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OK. I have a Redmax 621 and a 72 cc clone. The clone crankcase is aluminium vs magnezium. A lot thicker than the original.The crank looks similar,the cylinder and piston same shape but 50 mm bore. The case seems to have the blame for the weight diference. I don't have a 62 cc clone to compare,from pictures looks like the case is the same.
What is the weight of the real G621? I had expected the clone to be heavy but was surprised when it came in at 12.4lb (5.62kg).
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OK. I have a Redmax 621 and a 72 cc clone. The clone crankcase is aluminium vs magnezium. A lot thicker than the original.The crank looks similar,the cylinder and piston same shape but 50 mm bore. The case seems to have the blame for the weight diference. I don't have a 62 cc clone to compare,from pictures looks like the case is the same.
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Ok, it must just have been how it showed up on this phone. I'm pretty sure the 72cc is the same case - I'd like to see the cylinder and if the carb is the same size. The 62cc carb is 15.08mm, which is marginal for that displacement.
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1st one worked perfect that was embedded.
So is those 72cc ones on same crankcase as the 62cc?
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Either one worked fine for me.
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That link looks screwy. Trying this one: https://m.youtube.com/watch?v=AiEehRzrW7s&feature=youtu.be
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Here's the clone with a 20" bar in white oak, 3/8 full chisel. For most of the time it's running about 10,300rpm.
https://youtu.be/AiEehRzrW7s (https://youtu.be/AiEehRzrW7s)
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The timing on my clone was decent as it came, except for the intake. I removed the gasket and lowered and widened the intake. The timing (duration) ended up at:
E 160
I 159
T 122 (Blowdown at 19)
I left the exhaust port alone, and the final widths were: Exhaust port = 54% of bore, Intake = 52%
It seems quite willing to rev, and I suspect the smallish carb is holding it back some. It's got a very usable power band.
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the 621 takes well to porting just remember to port more for torque than rpms , its a cheap motor but you will be surprised at how much power you pick up , Donot go wild on porting as you can over port these jugs pretty quick . You want your max power at 10,500 or so , they are not a cookie cutter but once ported they sure will cut cookies or firewood for a long time
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Looks identical, just a cleaner casting. I know it's an open transfer cylinder, but it sure does run well.
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@Chris-PA here is a oem redmax 621 cylinder to compare in pics.
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Looks like my Zenoah G62 which has a Husqvarna labeled cylinder on it
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I have not yet seen a real G621 cylinder, but my clone was open port. The Chinese usually do not change the designs unless they have to, and anyway Zenoah sells both a G621 and aG6200, and I suspect the G6200 is the same as my clone.
My clone required only some work to the intake port and a gasket delete (and muffler mod) - cutting the base would have been better yet but I was lazy. I ended up at 0.035" squish, but the piston is domed and the combustion chamber is very small, so I suspect compression is pretty good anyway (I have no gauge but it feels healthy). It runs very well.
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@EHP used to port them. So you might ask him about them.
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IIRC the 621 is a open port engine?
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Hello boys. I have a Zenoah 621 i want to port. Anybody has some pics of a ported cylinder and piston? Thanks!
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My 6.2 is actually Zenoah G62 model airplane engine. The most common part about it and the 6.2 chainsaw is the cylinder and piston.
That Chinese company made G62 model airplane engine clones too for a very short while. I've seen pictures and for sale ads but never a actual clone engine.
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Thanks.
BTW, there was some discussion about the G621 being heavy in early posts upthread - my clone is 12.4lb, and it is slightly heavier than the real one.
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Yes
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Does the porting of the real G621 look like that of my Chinese clone?
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Seen inside a open port 621 the other day. Looked a lot like the poulan 60cc open port cylinders.
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Art can you not find another new one out there ,
New ones were gone from here about 2 years ago.
New old stock 5000 http://www.ebay.com/itm/Redmax-Husqvarna-division-arborist-chainsaw-G-5000-16-New-warranty-/290651989205?pt=US_Chainsaws&hash=item43ac3564d5
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Thats one saw I truly miss. Thought many times about seeing if it could find its way back home.
That Partner 5000 490 package deal perked my ears ;D. I'm am just so cash poor right now to put money into saws. But I am open to trades etc. 8)
You never know, may happen.
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Art can you not find another new one out there ,
New ones were gone from here about 2 years ago.
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Thats one saw I truly miss. Thought many times about seeing if it could find its way back home.
That Partner 5000 490 package deal perked my ears ;D. I'm am just so cash poor right now to put money into saws. But I am open to trades etc. 8)
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Art can you not find another new one out there ,
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Thats one saw I truly miss. Thought many times about seeing if it could find its way back home.
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I knew it was for cutting in the bush so I most likely cleaned the carb up but I'm sure I did not open it up , I find if you open them up to much sure they make more up at wide open throttle but not as good at 1/2 throttle , I do remember thinking that saw could use a bigger carb and I'm sure it would pull harder but then again it would be harder on gas
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you would be surprised , just a little carb work helps alot , same with the 5000 as its a small carb as well
Ed had you did any opening up or carb changes to the redmax 5000 I got off Art, that you had ported for him for pulp or limbing? I have never had to do anything to the saw so I havent ever had to look at anything. Very dependable firewood saw here and makes a decent 3ci gtg saw too (even though it wasnt made to be a cookie cutter).
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you would be surprised , just a little carb work helps alot , same with the 5000 as its a small carb as well
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I have a G62 cylinder laying around here somewhere? I'll try to get it staged to bring over to your house. It is open port.
The 621 saw cylinder appears common with the Zenoah G62 cylinder but the 62cc blower cylinder looks different.
With a HDA48 carb, they wouldn't be setting the world on fire.
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I feel they would make a descent firewood saw for most people , a touch heavy for falling timber , I think thou they were pretty cheap to buy but not as nice as say husky to work on
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Kevin it has been so long I cannot honestly remember and I built the bunch of them all in about a 3 month period but I do believe they were open port but donot take that to the bank ;D, They made quite a huge gain in power thou was ported
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Me and w8ye was having a discussion on redmax Sat. Was the 621 open port?
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we ran a stock brandnew 621 that we took out of the box against a 361 stihl that had 6 or so tanks of fuel threw it at one of the GTG in 16 inch or so hard maple , the 621 was just a touch faster than the 361 , Now I ported a bunch for Javilin or whatever his name is and they sure pick up alot on power , That was 6 years ago or so but never heard of them having any trouble
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47.5mm bore and 35mm stroke. Seems a little heavy PHO, going by Mike Acres site info.
http://www.acresinternet.com/cscc.nsf/ed1d619968136da688256af40002b8f7/e37b2b8e095847de88256d0a000b0b6a?OpenDocument
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It does not compare well with the saws that you listed for my work. Lacks limbing speed. The 621 is coil governed, makes ok torque and would compare well with a 61 Husky. Good saw for the wood pile.
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Has anyone ever ran a stock Redmax 621 to compare to any of these Efco 962 , Stihl 036 , MS361 , Husky 357 , 359 , 262 , 362 .
Just something I was wondering about the other night on how the 621 compared to the others.