[Rob UK]

Does anyone on here have any knowledge of the Hyosung 125 single cylinder motors? There seem to be a few bikes since the late 90s of theirs with 57x48.8 bore/stroke and an oil cooler, some offered in India. I'm mainly wondering if they are a Korean design or a Japanese clone?

[TheHelix0202]

Interesting. Which bikes were offered with this engine in India?

[GTO]

I see some mentions of single-cylinder Hyosungs on the forum (including the RT125D) - link.

[nitro.1000bhp]

Originally Posted by Rob UK

Does anyone on here have any knowledge of the Hyosung 125 single cylinder motors? There seem to be a few bikes since the late 90s of theirs with 57x48.8 bore/stroke and an oil cooler, some offered in India. I'm mainly wondering if they are a Korean design or a Japanese clone?

Long ago the Indian company kinetic had a tie up with Hyosung when they were selling their GF125 and 170 models. Not sure about the bore/stroke numbers as info about these is very thin on the internet because they flopped big time in India. I also doubt they were oil cooled. The 2 bikes they were known for was the comet 250 and Aquila 250s, both were vtwins.

I remember walking into a kinetic dealership back then to enquire about their Gf170 laser and the folks there vehemently denied that such a bike even existed . I promptly dropped the idea seeing their plight.

[Rob UK]

Originally Posted by nitro.1000bhp

Long ago the Indian company kinetic had a tie up with Hyosung when they were selling their GF125 and 170 models. Not sure about the bore/stroke numbers as info about these is very thin on the internet because they flopped big time in India. I also doubt they were oil cooled

GF125 appears to have the 48.8mm stroke single, probably the same engine as the bikes I am looking at.

Attached pic is a 1997-03 GA125F - single, oil cooler and dual kick/electric start, oil cooler on the front of the frame - more "cooled oil" than "oil cooled", and not all models using what looks to be a derivative of this engine appear to have one.

The reason I'm interested in them is that a group of us are planning a 3500km round the UK roadtrip on small cheap bikes. Some of the guys don't have a bike license and will be riding on a proficiency certificate, so limited to 125cc and <15bhp. These Hyosungs are seriously ugly, but they are cheap and have the full 14bhp, whilst most of the other cheap stuff is dreadfully built Chinese models with a 8-11bhp motor cloned from a Jap 2v commuter model. They are a bit marginal on UK roads - you'll drop a gear and hold about 45mph uphill, which means lightly loaded lorries fly up behind you on their 56mph limiter.

Personally, I will probably end up on an Indian built Bullet or something like a CB250N. You can get a decent older 15-25bhp bike cheaper than a decent Japanese 125 model here as there is little demand for 15-25bhp models now the middle category license is 47bhp instead of 33.

[Sankar]

I clearly remember these Kinetic Hyosung bikes - the commuter 125, the sporty and not so bad looking GF170 with dual circular tail lights, and finally the Comet 650 v-twin and Aquila 250 V-twin which were aspirational models back then. The 160cc Kinetic Blazer scooter must have been a Hyosung too I guess.

Originally Posted by Rob UK

I'm mainly wondering if they are a Korean design or a Japanese clone?

Hyosung had a collaboration with Suzuki and the engines are most likely to be based on the Suzuki designs. Suzuki Burgman UH125 (not sold in India) engine has identical bore x stroke 57x48.8 as the Hyosung and so does the TVS XT125. TVS had a long standing collaboration with Suzuki and most of their engines have Suzuki design origins.

[Rahulkool]

I remember taking a TD of LML Adreno FX. It was first motorcycle to feature 3 valve head in this segment IIRC. The engine had very little power in the bottom range and needs to revved hard to move. It was very refined, i had a HH CBZ back then.

Edit : 3 valve head not 4 valve !

[Rob UK]

Originally Posted by Sankar

Hyosung had a collaboration with Suzuki and the engines are most likely to be based on the Suzuki designs. Suzuki Burgman UH125 (not sold in India) engine has identical bore x stroke 57x48.8 as the Hyosung and so does the TVS XT125. TVS had a long standing collaboration with Suzuki and most of their engines have Suzuki design origins.

Great thanks, I knew the Hyosung 650 was the old Suzuki SV engine but it didn't occur to me that might mean the 125 is too

*edit* found a supplier of cylinder heads for the Hyosung GA125F and they are definitely 4 valve. Budget Suzukis on the GN/GS 125 range are not... more digging required!

[Sankar]

Originally Posted by Rob UK

*edit* found a supplier of cylinder heads for the Hyosung GA125F and they are definitely 4 valve. Budget Suzukis on the GN/GS 125 range are not... more digging required!
Attachment 2364845

Here is a GN125 4 Valve special edition. The 2v head seems is the most common spec for this engine, the 4v head might have been a special/limited edition in some markets.