Issues (Electrical?)

[grdaemon]

My Vstrom DL650 K5 has been acting up lately. It seems that the battery - A two years old Yuasa - has a voltage of 12.7V but it drains with minimal effort and does not start the motorcycle. I replaced it with another used one I had at home and the engine starts-restarts normally for now although the idle seems low to me. My question is if this has ever happened to you (with a battery that actually measures 12+V). Maybe given the increased age and mileage (188000Km) should the rectifier or stator be checked? Sometimes on rainy days or even with increased humidity it starts working with only one cylinder and after a while it works normally again. Everytime that happens I visit a motorcycle electrician and they either change the spark plugs or they pretend to fix the spark plug cable. Is there any chance that this is an issue that can be caused by valve adjustment? I was planning to take it in for adjustment these days, but with the suspicion that it might need something even more expensive like a rectifier or even a coil, I'm worried about a possbly super expensive "perfect storm" that I cannot afford..

[Rixington43]

There is a known issue on the Suzuki twins where they drop onto just the rear cylinder in rain, it occurs if the front plug lead isn't properly sealed with the cable lined up with the arrow so it sits in the correct notch on the valve cover. There is then a drain hole part way down the side of the block which allows any moisture ingress into the plug recess to drain, this can become blocked and then the plug gets wet and drops spark. The drain hole can be cleaned out using a piece of wire or, in my case, an old bike spoke worked well.
With regards the battery, I would suggest doing a voltage drop test and also testing the charging system.
If you have 12.7V at rest then keep the meter on the battery and try to start the bike, the voltage shouldn't drop below 10 or 11 even when the starter is cranking, if it plummets upon adding a load then the battery is cooked and not holding charge properly. Mine did exactly this.
If the bike starts then keep the meter on and see that you get around 14V with the bike running, rev the engine up and down the range and see if the voltage holds steady. If it does then your charging system is OK. If the battery drains when the bike is standing then you may have a vampiric drain, if this has led to needing to charge the battery from flat a few times then that may have degraded the battery.
I wouldn't expect valve clearances to effect the electricals or running on one cylinder, out of spec valves usually result in the bike running hot and drinking fuel before they would drop a cylinder.
Idle being low could be the fast idle system being out of whack or the secondary butterflies not functioning correctly, I would get your charging/starting issue sorted first and then get the valve clearances done as re-balancing the throttle bodies and resetting the idle should all be taken care of as part of the valve service.

[Upt North]

My 2017 shows around 12.7 with the engine off.
Drops to 11.3 whilst cranking.
Then rises to 14.4 when running.
I'd check your voltages as suggested and if the present battery works OK, ride.
At the mileage you're stating 188,000 KM, it obviously may be due some work, that's if you didn't type another 0 by mistake. That's a lot of miles.
It wouldn't hurt to change the plug leads
Good luck.
Upt.

[Brockett]

Cleaning out the spark plug recess drain is a good idea. Just as long as you make sure no debris has settles in the plug recess. Otherwise when the spark plug is removed the debris can fall through the plug hole and into the cylinder.  If possible use an air line to blow out the plug recess before removing the plug.

[Gert]

Fault finding is a process of eliminating / ruling out one thing at a time.
On your K5 Wee, you can turn the hot idle speed up by adjusting the remote idle screw in the Y of the frame by the riders left knee. See the K4 manuals available under https://www.v-strom.co.uk/downloads.htm

Once the idle speed is correct, I suggest that you test the charging system.
A few tests to rule out the battery as a first step:
1) battery terminals clean and tight?
2) perform a load test on the battery - the load test method of taking a voltage reading of a rested battery as a before reading and again while the motor is cranking, will help to determine whether the battery needs replacing. Another alternative is to simply have a battery center perform a load test and give their verdict on the battery condition.

Next step is testing the charging system:
1) take a voltage reading at idle speed and then another reading at above 4,000 rpm. Share these readings, so that the members here can offer advice or comment on the readings and the next steps to perform.
2) the next steps would be testing of the stator output voltage, stator coil resistance testing, stator earth leakage testing.  The stator stesting is discussed in the service manual.
3) the final step in the charging system would be the voltage regulator testing.

The flow chart (fault-finding-diagram charging system.pdf) that is attached in the opening post of https://www.southbayriders.com/forums/threads/145945/ may be of interest.

[grdaemon]

Battery terminals are fine. Three days later it still turns on with a low rev idling. Lots of rain these days so no chance to check the rest but Hello, I took a video https://youtube.com/shorts/CtZRI8h_JAU?feature=share 

[grdaemon]

Battery terminals are OK, didn't have the opurtunity to continue with those test because of rain. Ill see into them this weekend. So far the motorcycle turns on, low rpm idling. Video >