Reply To: Cold startup issues – GV125 Carby
Hi everyone, I have just bought 2016 hyosung GV125 Classic 2016 , I have done full service, new oil , filters , plugs etc , and what issue I have is basically difficulty to start up when cold , it will take up to 30seconds before it will start , as soon bike is warm it starts straight away, have you got any suggestions what else I could check or adjust?
Welcome and to your friend on here too lol. Okay, how about this?
- When was the last time the carb even had an ultrasonic clean? (a very big deal)
- Valve Clearances? (Loose valves make it hard to start cold, heat tends to narrow gaps , hence easier starts, but power will be lacking in general , so either, get some proof the valves were done in the last 4,000 miles as per Korea’s rules, it is a lot of valves for a 125 after all 😬
- What fuel do you use ? E10 , E5 Super ? which stations ?
- Have you ever had the airbox off ? (We have 2x tutorials for that in the tutorial section) (Bad “o-rings” under the manifolds , make it quite annoying to start , however engine can reach 100c degrees, eventually the orings will cake and need replacing, since it will allow particles and dirt to mess up the air system and the carb since they are upside down sending air down the engine with atomized fuel for plugs to spark properly)
- Owner messed with the jetting or carb mixtures?
- Replaced the plugs ? – Be ready to replace them again with another set of normnal CR8E (only that size please) – If the air system or carb system ain’t right, the plugs foul easily (you’re welcome to post plug colours on here to see how well it is doing)
It’s a lot to ask I know, but don’t rush, i will have a proper answer based on data you gave us. Assumptions could mean false diagnosis (i said this, when it was actually something else etc) , so I want to be as accurate as i can 😉 , considering i fix these bikes all the time.
hello , thank you for your response,
I must admit I have very little knowledge of what has happened to my bike before I have purchased it , basically old man passed his full license and he kept this on I a garage for 5 years,
If we are talking carbs , and valves I have very little knowledge of how to adjust / clean if necessary ( new to motorcycles world) however there are no lack of power while bike is running, idling approximately steady 1400rpm no issues with revs , acceleration etc , alternator works perfectly fine with 14,3 output, I have fitted new battery, new air filter ( carbs looked clean ) when I looked when filter was removed however I did not inspect -rings ( lack of experience and I will re check again ) im using currently E5 shell petrol , and I have added liqui Moly fuel system cleaner , as bike was not used for a long while , before first start up I have drained old petrol and replaced with new , when I bought this bike plugs inside were CR7HS but I have replaced them back to NGK CR8E spark was strong after installation ( checked before putting them in ) old plugs were black and I’m attaching pictures, bike seemed to run rich at the beginning due to stron petrol smell from exhaust but after replacement it has gone a lot better,
thank you for your recommendation and suggestions it is much appreciated, shame you are far away from Stockport as I probably would pop in to you and let you do full in depth inspection.