The Japanese originals had a single stroke value and this was 31 mm. They used 2 bores: 43 mm and 45 mm, giving a displacement of 45 cc and 49.3 cc. The Chinese versions generally use 2 stroke values and these are 32 and 34 mm. For 32 mm as in the Japanese originals there are 43 and 45 mm bores, which gives an engine displacement of 46.5 and 50.9 cc. The Chinese refer to these as 45 and 52 (cc). For 34 mm there is a bore of 45.2 mm, which gives a displacement of 54.6 cc. The Chinese describe them as 58 (cc). Much rarer is the 48 mm diameter, which gives an engine displacement of 61.5 cc. Such engines have a different piston wrist pin diameter and this is 10 mm instead of 11. Consequently, the needle bearing is also different. Here there is a similarity with the Japanese G620(x), which is a different design from the G450(x)/G500(x)/G520(x). To add to the confusion, it is common for companies selling chainsaws to describe '58' models as 62 cc. Most often the crankshafts can be easily distinguished because those with a longer stroke have 58 stamped on them. This is probably also the case with the crankshaft you show in the video.
Nice info thanks, my cranks are unmarked probably because they are after market, and yes I have some bores at 45mm but I also have 2 that are 47mm, all aftermarket.
@@marklutwyche8578 Whether it is AM or not is rather irrelevant for these saws. They can be described as a commodity. One of the crankshafts you show in the video has PS52 stamped on the crank rod, meaning it is designed for use with '45' and '52' cylinders: 32mm stroke. On the one intended for cylinders with 34 mm stroke ('58' and '62'), unfortunately no markings can be seen, because if there were any, they have disappeared. All the longer stroke shafts I have seen have always had 58 stamped on the connecting rod. Those with a shorter (normal)32 mm stroke didn't always have the '52' marking on the crank rod, but they often do, like the one in this video. Such a built-up three piece crankshaft with the press-fit between the crank pin and the crank halves is a standard on all good quality saws. It all depends on the quality of the materials and workmanship, as well as the final heat treatment. The fact is that Zenoah used a different shaft for their 53 and 62 cc saws. Such saws also had a different design, for example they used an internal clutch which was also quite a lot bigger. The Chinese also sell copies of these larger saws, but they are much rarer and more expensive than the ubiquitous G45xx/G5xxx copies/clones/whatever.
The Japanese originals had a single stroke value and this was 31 mm.
They used 2 bores: 43 mm and 45 mm, giving a displacement of 45 cc and 49.3 cc.
The Chinese versions generally use 2 stroke values and these are 32 and 34 mm.
For 32 mm as in the Japanese originals there are 43 and 45 mm bores, which gives an engine displacement of 46.5 and 50.9 cc. The Chinese refer to these as 45 and 52 (cc).
For 34 mm there is a bore of 45.2 mm, which gives a displacement of 54.6 cc. The Chinese describe them as 58 (cc). Much rarer is the 48 mm diameter, which gives an engine displacement of 61.5 cc. Such engines have a different piston wrist pin diameter and this is 10 mm instead of 11. Consequently, the needle bearing is also different. Here there is a similarity with the Japanese G620(x), which is a different design from the G450(x)/G500(x)/G520(x).
To add to the confusion, it is common for companies selling chainsaws to describe '58' models as 62 cc.
Most often the crankshafts can be easily distinguished because those with a longer stroke have 58 stamped on them. This is probably also the case with the crankshaft you show in the video.
Nice info thanks, my cranks are unmarked probably because they are after market, and yes I have some bores at 45mm but I also have 2 that are 47mm, all aftermarket.
@@marklutwyche8578 Whether it is AM or not is rather irrelevant for these saws. They can be described as a commodity.
One of the crankshafts you show in the video has PS52 stamped on the crank rod, meaning it is designed for use with '45' and '52' cylinders: 32mm stroke.
On the one intended for cylinders with 34 mm stroke ('58' and '62'), unfortunately no markings can be seen, because if there were any, they have disappeared.
All the longer stroke shafts I have seen have always had 58 stamped on the connecting rod. Those with a shorter (normal)32 mm stroke didn't always have the '52' marking on the crank rod, but they often do, like the one in this video.
Such a built-up three piece crankshaft with the press-fit between the crank pin and the crank halves is a standard on all good quality saws. It all depends on the quality of the materials and workmanship, as well as the final heat treatment.
The fact is that Zenoah used a different shaft for their 53 and 62 cc saws. Such saws also had a different design, for example they used an internal clutch which was also quite a lot bigger.
The Chinese also sell copies of these larger saws, but they are much rarer and more expensive than the ubiquitous G45xx/G5xxx copies/clones/whatever.
Thank you for the useful information 👍