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gv650

GV650 low rpm issues

I am the proud owner of a GV650P (2017) it has an ixil exhaust which is made for this model just the end can not a complete system the issue is a jerky throttle response at low rpm and if  you open it up in the wrong gear it coughs and splutters .The tick over can be a bit erratic once warmed up but can be settled down by turning her off then restarting , so that said does anyone have an idea what could be this issue and is there a power commander for this model and year . Finally it may be an imbalance in the air sensors but that is just guessing is there a high flow air filter for this machine it’s not the can type (already got that wrong , got one from DNA filters) but the flat type .

Many thanks

 

 

Hyosung GV650 Trend Killer

Hello from DownUnder 🙂

Enjoying my GT250R but currently on the lookout for another bike. Only thing better than a Motorbike, 2 Motorbikes 🙂

Very much liking the look of the GV650 and they are well priced down here. As i mentioned they look awesome but then in my searching I found something that looks baller.

The Hyosung GV650 Trend Killer was a kit you could get some time ago, thinking 10 + years. Anyone seen one of these in the wild?

One article I read mentioned the kit was created by a German company. Just curious and thought it would something others may find interesting.

Hyosung GV650 Trend Killer Custom

UM V2C-650S (Hyo gv650)

Hello fellow riders, I just got this “project” bike from a guy on the internet. Title says United Motors and branding on the bike as well, however from searching the internet it’s a rebranded GV650 for US market. I have rebuilt the almost all brake/electrical/fuel components myself and finally am trying to attach the air box/fuel tank + fuel/vacuum hoses . These were already disconnected or missing when I took delivery of the bike. Now then on to the problem I am having, there are no direct diagrams for the all the parts I have. I’ve looked into so many parts catalogs/service manuals, and none of them have them listed. I’ve stumbled across a post about the AIS delete and fuel/vacuum line routing for 125/250 but not for my motorcycle, hopefully the pictures can explain along with this post.

https://imgur.com/gallery/eF7ekkE

St7 gv650 Classic coolant level

Hi, I have a gv650 Classic (the 650 version of the ST7) here in Australia.

The problem is when I go to check the coolant level in the reserve bottle, I can’t see the F or L marks because there is a metal cover and heat shield covering a lot of the bottle.

Any help please?

 

GV650 oil pressure

Hi,

I see in the manual that there is a oil pressure check bolt where you can screw in a oil pressure guage to check oil pressure.

Has anyone permanently mounted a oil pressure sensor there?

I am looking to mount  a combined pressure/temperature sensor to a guage on the handlebars any just wonder if anyone else has done it?

GV650 2007 Speedometer LCD Program Software

Hello everyone, because of the regulator rectefier fault my speedometer’s capacitors died, and we changed it and bring speedometer back to life. But program in the digital integrated circtuits is not working and my speedometer not works functionally. I need a solution and hope you guys would help me.

(Sorry if i did any misspelling my English not that good.)

[How to Tutorial] [Bike Mod] 650/250/125 – AiS Block Off Removal (EGR Delete)

Hyosung AIS Removal Guide: EGR Delete for GT650, GT250 & GV125

âš  WARNING: This technical guide involves modifying the Air Injection System (AIS). Proceed at your own risk. Incorrect installation can affect engine longevity or emissions compliance. Ensure you have the correct tools before starting.

If you are looking to improve the exhaust note and throttle response of your Hyosung GT650R, GT250, or GV125 Aquila, performing an AIS (Air Injection System) block-off—often referred to by riders as an EGR Delete—is one of the most effective “free” mods available. This process is common among race teams and enthusiasts looking to strip away parasitic emissions equipment.

What is the AIS (Air Injection System)?

The AIS is designed to help motorcycles meet strict Euro emissions standards by injecting fresh air into the exhaust port. This helps burn off unburnt fuel in the header pipes. While great for the environment on paper, it often causes excessive “popping” on deceleration and adds unnecessary clutter to the engine bay. It essentially “fakes” cleaner emissions by diluting exhaust gases, acting like a parasite that steals potential engine efficiency.

Benefits of the AIS Block-Off Mod

  • Reduced Exhaust Popping: Eliminates the loud, annoying backfiring often heard with aftermarket stainless steel exhausts.
  • Improved Induction Roar: Gives the bike a deeper, more natural groan at idle and under load.
  • Smoother Mid-Range: Many riders report a noticeable improvement in the 4,000–7,000 RPM range, particularly on smaller 125cc and 250cc models.
  • Simplified Maintenance: Clears up space around the cylinder heads, making spark plug changes and valve clearances easier.

Whether you are running a stock setup or a full custom exhaust system, removing the AIS is the first step toward a true performance tune. Full credit goes to the original community author who compiled this technical manual.

Ready to start the mod? Download the step-by-step technical book below:

Community Note: This mod is highly recommended if you have recently upgraded to a Delkevic or similar aftermarket silencer.

[Tutorial] Hyosung GV650 & GT650: Tip Over Sensor (TOS) Bypass Mod & C23 Fix

Fixing the C23 Error: GT650 & GV650 TOS Modification

If your Hyosung GT650 or GV650 is showing a persistent “FI” error on the dash and refusing to prime the fuel pump, you may be dealing with a faulty Tip Over Sensor (TOS). When this sensor fails, the ECU assumes the bike has crashed and cuts the ignition for safety. This guide explains how to bypass the sensor using simple resistors to get your V-Twin back on the road.

🔧 Diagnostic & Modification Info

The TOS is designed to kill the engine if the bike tilts past a specific angle. Over time, the internal float can stick or the circuit can fail, triggering the Dealer Mode Error Code C23. A new sensor can cost upwards of £80–£100, but a bypass can be made for pence.

  • Fault Code: C23 (Tip Over Sensor Malfunction).
  • The Symptoms: “FI” on dash, fuel pump won’t prime, engine dies after 2 seconds.
  • The Fix: Replacing the internal sensor circuit with two specific resistors to “trick” the ECU into seeing a safe upright position.
  • ⚠️ Warning: This mod disables the automatic engine kill-switch during a crash. Perform at your own risk.


⬇ DOWNLOAD TOS MOD GUIDE (.PDF)

Credits: We owe a massive thanks to the original author for documenting this electronics bypass. This PDF is a permanent mirror hosted by HyoRiders. If you’ve successfully cleared your C23 error using this method, please leave a comment to help others!

[DOWNLOAD] Service Manuals & Owners Books – Hyosung GV650 & GT650 (Carb & EFi)

Hyosung 650cc V-Twin Master Resource

Welcome to the complete documentation archive for the Hyosung GT650 (Comet/R/S) and GV650 (Aquila/Avitar). These 650cc machines are the powerhouses of the Hyosung range, featuring the iconic 90° V-Twin DOHC engine. Whether you are synchronising carburettors or diagnosing a Delphi/Denso EFI system, these permanent direct links provide the official data you need.

650 Series Generation Guide

Identifying your specific 650 model is critical for correct electrical and fueling maintenance. The GT and GV series evolved through several major technical phases:

  • Carburetted (2004–2008): Features dual Mikuni carburettors and the classic “silver” engine finish.
  • Gen 1 EFI (2008–2011): Transition to Fuel Injection. Uses the “S&T” or “Mitsubishi” marked systems with a green LCD dashboard on GT models.
  • Gen 2 EFI (2012–2018): Features a major visual facelift (RC for Sports, P for Naked) and the upgraded Denso/Delphi ECU systems.
  • 2024+ GV650 ABS: The latest revival (GV650PJ/PC) featuring full LED electronics and ABS. (Manuals pending; see specs link below).

Technical Note: The 650 engine produces approx 79hp (Carby) to 74hp (EFI) and requires 10W40 semi-synthetic oil (~3.0L with filter). For 2024+ models, visit our GV650 ABS Wiki & Specs Page.

đź›  WORKSHOP SERVICE MANUALS


⬇ SERVICE MANUAL – GT650 & GV650 (Carby)

⬇ EFI SERVICE MANUAL – S&T / Mitsubishi

⬇ FI SERVICE MANUAL – “Fi” Marked Models

⬇ EFI SERVICE MANUAL – Denso (2012+)

đź“• OWNERS HANDBOOKS

Safety Notice: Ensure you are using the manual that matches your ECU type (Mitsubishi, Delphi, or Denso) to avoid electrical damage. If you have documentation for the 2024+ GV650 ABS models, please contribute by commenting below. All links are permanent mirrors hosted on the HyoRiders servers.