Reply To: GV650 FI 2002 – REGULATOR / RECTIFIER Instant overheat
Good discoveries there!
As far as i know on my side , all the GVs i ever touched being Fi models , they used a 30A fuse for the fuel pump side, its own fuse box i should say, the 2nd fuse box will be 15A for general electronics , the lights took 20A relays , and there is also a mixture of 20A and 30A relays in the battery rack.
I don’t know if you have a minor harness revision for your market, can you confirm how many relays the bike is using and how many fuse boxes are there , they should match the UK daewoo ones I lay hands on.
The black pump is very thirsty , it draws a lot but it is a given since it’s constantly running.
Heat is the enemy => Check if possible the values of the water temperature sensors in the thermostat and radiator fan switch , and other temperature sensor on the bike. Now i did get an error from the ECU where it ran cold fine, but it was rough , the Fi flashed a sequence telling me to replace the engine sensor that checks cylinder temp.
Another heat problem i faced with a different GV was that it actually shut down mid-ride and had to wait for it to cool down, it was the stator’s pickup coil gone haywire and the engine was popping a lot.
If you unplugged everything except the pump to keep the bike running , I would check:
- Temperature related sensors / Lambda Sensor
- Fan Switch (unless the radiator is ice cold for 15 minutes and the fan hasn’t come on yet?)
- These sensors tend to send OHM readings back to to the ECU, so if the value is off , the ECU just cuts off the fuel pump supply., then the bike dies.
You mentioned that sometimes you hear the cylinders dropping in and out?
- Would the primary and secondary resistances of the coils be affected too drastically ? Ie. (the coil without the CAP attached would say 15K Ohms but after 15mins, it jumps to 40K ohms hot ?) OHMS will go up and down based on temperature which is normal but not too much as there is a range of values accepted by the service manual.
- Get NGK Caps if possible (if you have already , check their resistance without the coil attached) , we don’t know if they waned, then the sparks drop when it gets hot , as it gets pretty hot inside those engine heads where the plug caps go to. So hence we really don’t trust the OEM caps (the black ones) they are the first things to go.
If not, try SV1000 caps (should be OEM ones) and yes it is a good call to check your plugs and the coils themselves.
I could not give you a true figure of what amperage every item uses on the GV650 , as Hyosung changed many parts over the years (Carb, Mitsubishi EFi (rare), Daewoo, Delphi , along with harness revisions sometimes for the same ECU. My delphi uses 20A relays where the Daewoo used a mixture of 30A and 20A, but i would change all the relays and see if the power draw has improved ?
I would really hope the ECU is OK, but be ready to hunt hard for a spare one (practically scour the earth for it) or get a Delphi Harness and Delphi ECU as plan B if we cant replace the ECU , however a crashed GV650 will be a good donor for testing also before messing too much with your live one, so keep an eye or just as a back up.
ECU could possibly die due to heat (I can’t confirm if it has an internal temp sensor like a PC CPU does where if it reaches a TJMAX it shuts down to avoid as fire but , i believe this daewoo ECU is a little more primitive than the Delphi ECU, so i can’t assume 100% correct on my assumptions here , or otherwise , we could suspect a small piece of circuitry inside the ECU is now more heat sensitive since it was spiked before but i hope not, otherwise a dead daewoo ECU just wont even entertain the pump to prime before starting.
For your RR, if it gives off 14V but blows a 15A fuse, that’s crazy , we might have a problem of resistance , i only ever experienced a blown fuse from the excessive draw from the fuel pump waning or the stator was waning (hence on my previous reply in regards to heat on the connectors)
I have a theory , what if we source a battery pack 12V a good one that’s not going to harm the motorcycle , disconnect the stator, disconnect the RR , let the bike run purely of the battery pack but do add an inline fuse to be safe and see if it dies out ? – You could measure how much juice it is drawing from the battery and how rapidly does it deplete the battery , you could use another spare good bike battery for this too. It is a theory for you!