Porting a Chinese G621 Clone

[Hus12]

Chris I think you have a great project.
I only started playing with saws when I started servicing a friends saws which led to a hole garage full .
I have been in the middle of the stihl husqvarna argument many times in the garage which led me to buy a cheap 62cc clone saw . Long story short Also add a milling machine and a lathe in the mix I'll put my clone up against any husky or stihl any day of the week .

 

[Chris-PA]

Chris I think you have a great project.
I only started playing with saws when I started servicing a friends saws which led to a hole garage full .
I have been in the middle of the stihl husqvarna argument many times in the garage which led me to buy a cheap 62cc clone saw . Long story short Also add a milling machine and a lathe in the mix I'll put my clone up against any husky or stihl any day of the week .

The clones sure have their share of assembly errors, but they are pretty faithful to the original design. In modding mine I only really lowered and widened the intake a bit, ditched the base gasket and advanced the timing. The muffler was good enough.

I'm surprise the original G621 was not more popular, considering the weight and performance. The engines apparently have a following in the RC world:

 

[Hus12]

The clones sure have their share of assembly errors, but they are pretty faithful to the original design. In modding mine I only really lowered and widened the intake a bit, ditched the base gasket and advanced the timing. The muffler was good enough.

I'm surprise the original G621 was not more popular, considering the weight and performance. The engines apparently have a following in the RC world:
View attachment 350774

 

[Hus12]

I have one with a mate running weeks on hard ball at his farm , for under $200 to my door how can you complain .

Thinking of adapting a husky 372 head on a 72cc baumr

 

[Terry Syd]

Just to clarify, is the 72cc saw the same chassis as the 62cc saw? In other words, the same weight?

 

[Chris-PA]

Just to clarify, is the 72cc saw the same chassis as the 62cc saw? In other words, the same weight?

Terry, from all the pictures I've seen they are the same, and I cannot imagine the displacement increase would change the weight much. Hopefully Thommo will reply.

 

[heyduke]

I have one with a mate running weeks on hard ball at his farm , for under $200 to my door how can you complain .

Thinking of adapting a husky 372 head on a 72cc baumr

can you translate to english? thanks.

 

[Thommo]

Just to clarify, is the 72cc saw the same chassis as the 62cc saw? In other words, the same weight?

My 72cc Baumr ag chainsaw looks identical and has a dry weight of 9Kg I just weighed it with my bathroom scales and it weighed 7Kg with a 20"bar and chain so the weight shown in the manual is not correct.

 

[Hus12]

can you translate to english? thanks.

I have a friend who is clearing a lot he has purchased . I've given him a baumr 72cc chainsaw to use and basically told him to brake it .
It has been a year and a bit and the saw is working and performing perfectly.
I purchased the saw from eBay for under $200 added that it was broken down and rebuilt correctly.

 

[Terry Syd]

My 72cc Baumr ag chainsaw looks identical and has a dry weight of 9Kg

Is that powerhead only? I noticed that there is also a 66cc model that looks similar, but I don't know the weight.

 

[Thommo]

Is that powerhead only? I noticed that there is also a 66cc model that looks similar, but I don't know the weight.

I might have to weigh it myself tomorrow to find the exact weight. The manual that came with the saw just says 9KG dry. I have put a 20 inch bar on mine because it was a bit nose heavy with the 24 inch bar and i rarely cut anything that big now.

 

[Hus12]

I also found the 24 inch bar nose heavy and to big for what I need , a 20 inch would suit me .

 

[Chris-PA]

I had trouble finding an accurate weight for the Zenoah G621, and the numbers on the clones did not seem reasonable. That's why I was surprised when mine weighed in under 12.5lb (5.7kg).

It is nose heavy with a 24", and the bar that came with mine is actually 25" and even heavier than the Oregon 24" I have.

My dad told me he has a big oak log to buck up, so I'm taking the saw with a 24" bar over today.

 

[heyduke]

I have a friend who is clearing a lot he has purchased . I've given him a baumr 72cc chainsaw to use and basically told him to brake it .
It has been a year and a bit and the saw is working and performing perfectly.
I purchased the saw from eBay for under $200 added that it was broken down and rebuilt correctly.

thanks for the translation from ozish. i haven't found anything bigger than 62cc, which is a bit small for what i do. i don't think redmax ever built anything bigger than that. could yours be a husky clone? also, it looks like quality varies wildly. my saw would never have lasted for even one day, non-functional air filter that sucks in chips better than my shop vac, , very poor piston rings, bad crankshaft seals, unpredictable chain brake, bad throttle linkage, generally poor plastic. i agree with you on the 20 inch bar, maybe even an 18, just for balance.

 

[Chris-PA]

thanks for the translation from ozish. i haven't found anything bigger than 62cc, which is a bit small for what i do. i don't think redmax ever built anything bigger than that. could yours be a husky clone? also, it looks like quality varies wildly. my saw would never have lasted for even one day, non-functional air filter that sucks in chips better than my shop vac, , very poor piston rings, bad crankshaft seals, unpredictable chain brake, bad throttle linkage, generally poor plastic. i agree with you on the 20 inch bar, maybe even an 18, just for balance.

One of the modifications the Chinese manufacturer (I think it is Zhongjian Tools Manufacture Co.) does seem to do is displacement increases. The Earthquakes are available in a 41cc version of the G3800, which Zenoah never made. This is the Baumr-AG 72cc, which you can see is basically the same (although I like the modified filter cover design better).

http://www.agrmachinery.com.au/buy/24-72cc-pro-chainsaw-with-e-start/CHNSAW-BAUM-72SX

Sometimes they make more significant changes to the plastic covers:

 

[Hus12]

Quality does vary .......
There are bigger ones on eBay under baumr there is also a 80cc version for under $300 .
I soon as I receive a good quality copy saw I'll let every body in on it till then I agree with you on the pistons right down to the air intake . My personal saws have been completely rebuilt from the ground up , having a cnc machine is handy .
I'm only messing around with them because of the husky and stihl debate . My mates are in the tree business not me . They continually go on and on about husky or stihl that's when I stepped in.

 

[heyduke]

One of the modifications the Chinese manufacturer (I think it is Zhongjian Tools Manufacture Co.) does seem to do is displacement increases. The Earthquakes are available in a 41cc version of the G3800, which Zenoah never made. This is the Baumr-AG 72cc, which you can see is basically the same (although I like the modified filter cover design better).

http://www.agrmachinery.com.au/buy/24-72cc-pro-chainsaw-with-e-start/CHNSAW-BAUM-72SX

Sometimes they make more significant changes to the plastic covers:

right, i got on ebay-au and found the baumr-ag saws. there's an 82cc model too. unles they increased fuel tank capacity, you'd spend a lot of time filling them.

 

[heyduke]

Quality does vary .......
There are bigger ones on eBay under baumr there is also a 80cc version for under $300 .
I soon as I receive a good quality copy saw I'll let every body in on it till then I agree with you on the pistons right down to the air intake . My personal saws have been completely rebuilt from the ground up , having a cnc machine is handy .
I'm only messing around with them because of the husky and stihl debate . My mates are in the tree business not me . They continually go on and on about husky or stihl that's when I stepped in.

yeah- my saws are tools, not a religion. and the only "new" epa approved saw that i care for at all is the husky 575. that's not because it's all orange but because of its wide power band and abundant torque.

regarding your practice of blue-printing your saws before they are deployed, it sounds like a good idea but there are a couple of things that would be hard to catch if you didn't have the hard experience of dealing with them, the muffler failures, the air filters that don't, and who would expect a flywheel-side crank seal to fail after a couple of hours. tt's like the saw was trying to find a new way to suck in more saw dust!

 

[Chris-PA]

Here's another - the rear clutch side A/V mount partially tore today. I pulled it out when I got home, and I suspect it is because the casting hole has a bit of an edge all round - it's not awful but might be enough to cut the mount after a while. I will smooth it with a sanding drum on the dremel before I put the new one in (I picked up a lot of spare ones off eBay previously, just because they are wear items).

Other than that the saw cut well. Cold start was 3 pulls, and hot start was one pull every time. The thing cut very well, and I was working it hard. I was cutting up a 30" white oak trunk that the big "A" arborist company left at my dad's place. It was a 120yo healthy tree that was on the opposite side of the road from the power lines, and of no more threat to the lines than the half dozen other trees they left that were growing right over the lines. They took a lot of his wood but left the big trunk, as it it got caught up in a pole support wire, was sitting on rocks and had a 6" poison ivy vine on it. Never even talked to him about it. They wouldn't get away with that crap on my property.

Anyway, I managed to keep the chain out of the rocks, avoid the support cable, and apparently just missed some iron inside the tree (to judge by the black stains). And I got to hang out with dad cutting wood, and mom made a great dinner. That counts as a good day in my book!

 

[Thommo]

Well i just had a weigh in for my Baumr-ag saws. The Sx72 weighed it at 7Kg or 15 lbs with the 20" bar and 5.5Kg without bar. My SX62 weighed the same and the SX45 was .5Kg lighter. The 62cc saw that we get here is a different design to the 72cc. The 62cc saw needs to have the impulse hose modified so that the saw doesnt lean out when it warms up and the 45cc saw is the same. I just threaded a piece of thin copper pipe inside the impulse hose and bent it to shape to stop it from sucking in an closing off when the motor warms up, and the saws have worked perfectly since.