[SkylineGTR]

I have a Yamaha FZ25 BS6 model, bought 8 months ago. I have a rather strange issue with the bike: it will randomly fail to start on some occasions, behaving as if it has run out of fuel. I will have to crank it 4 to 5 times in order to start the engine, sometimes by giving it some throttle (which is bad for FI vehicles)

The issue happens completely randomly so far however I have noticed some patterns

• It never happens in the morning when I start the bike to go to work
• It mostly happens when the bike is started a short time after turning it off. Say I get home from the gym, park it, then 20 minutes later I have to go out, so I start it again; and it refuses to start.
• Many a times this happened when the bike was parked in direct sunlight. I have a theory that the sun is causing the injectors to heat up and making the petrol inside them evaporate, requiring extra fuel when starting again. Cranking it 4-5 times provides this extra fuel which allows it to start. Don't know if this theory is technically sound though. Another reason I am not sure about this theory is because it has sometimes happens in evenings too, after sunset.
• Everytime this happened, the bike was parked on a side stand. I initially thought it had something to do with the side stand kill switch but the SVC said it was all good.

Its not a major issue, but it is still annoying to have a new machine behave unpredictably. You expect starting trouble on machines with carburetors, not FI ones.

Any advice is appreciated, thanks in advance

[boniver]

Originally Posted by SkylineGTR

Any advice is appreciated, thanks in advance

Next time it refuses to start, try opening the fuel lid and closing it and then try to start the bike again. Worth a shot.

[Balaji31582]

Originally Posted by SkylineGTR

I have a Yamaha FZ25 BS6 model, bought 8 months ago. I have a rather strange issue with the bike: it will randomly fail to start on some occasions, behaving as if it has run out of fuel. I will have to crank it 4 to 5 times in order to start the engine, sometimes by giving it some throttle (which is bad for FI vehicles)

Any advice is appreciated, thanks in advance

It happened to my FZS25 also. I was told that we need to maintain certain fuel level as sometimes when we have the bike with side stand it could eventually take little more seconds to regulate the fuel flow. I also have a main stand added to my bike. I also tried using main stand but still had this issue. I am not 100 percent sure about this theory. But once I start maintaining the fuel level with minimum 2 bars, I haven't face this.

[windrider]

Get the fuel lines checked for small leaks or blockages. Also get the injectors and fuel pump checked since you say the bike is behaving like it is not getting fuel. If these three systems are fine, ask the service centre to check for any electrical issues. I had similar experiences with an old Suzuki gs150 and my own BS3 unicorn and the culprit was a faulty CDI unit in both cases. They would run fine most times and out of nowhere start behaving strangely. Sometimes they would turn off as if starved for fuel and refuse to start. Then after 5 minutes would turn on as if nothing happened Mind you, the bikes were already around 8 or 9 yrs old at that time, so I don't know if this issue can arise in such a new bike. Could also be due to fouled spark plugs.

[RD150]

Hey, faced the same issue with my R15 long time back.
Please check if,
1. Fuel pump is ok
2. If there's water in fuel tank
3. If injectors are ok

[SkylineGTR]

Update: This happened thrice yesterday: once after being parked in sunlight (which required 4 cranks) and twice in the evening(required two cranks to start). Don't know what to make of this.

Originally Posted by boniver

Next time it refuses to start, try opening the fuel lid and closing it and then try to start the bike again. Worth a shot.

Will try

Originally Posted by Balaji31582

It happened to my FZS25 also. I was told that we need to maintain certain fuel level

I always keep the fuel level above 50%.. don't think that's the issue.

Originally Posted by windrider

Get the fuel lines checked for small leaks or blockages. Also get the injectors and fuel pump checked since you say the bike is behaving like it is not getting fuel. If these three systems are fine, ask the service centre to check for any electrical issues. Could also be due to fouled spark plugs.

Can plugs foul on a 8 month old bike?
Can these checks be done myself? Or will I have to take it to the SVC?

Originally Posted by RD150

Hey, faced the same issue with my R15 long time back.
Please check if,
1. Fuel pump is ok
2. If there's water in fuel tank
3. If injectors are ok

How do I check for water in the tank? The other two I guess will be done by the SVC.

[windrider]

You can open up the spark plug yourself and check it's condition. If it appears burnt or covered in soot or oil, get your bike to the svc and show them the same. Since it is a fuel injected bike, there is not much you can do on your own. Also ask them to check the fuel injectors and fuel pump for any blockages caused by impure fuel or particles. Have you tried filling up from another pump?

[Baristyro]

- Maintain a chunk of fuel, basically 2-3 litres of pseudo-fuel capacity one shouldn't ever use, lest you cook your fuel pump
- Contend with an inaccurate digital fuel-level indicator
- Protect the fuel pump like an infant, from the heat, from the water, from itself!
- Clean the throttle body every so so kms
- Shoddy self-starter motors, along with no kick start to start with...
- Connectivity features that may randomly drain the battery
- Fragile ECUs about which regular mechanics know jackshit, replacement is guaranteed a 5-figure slap to the pocket

Why are these BS6 bikes such wussies?! How did we come from an era where some bikes used to function completely normally without any battery, or without any fuel in the tank(fuel in the carburetor), to these dark times where one risks catastrophic failures by using all the fuel that they pay for. A double whammy for someone who lives paycheck to paycheck, for whom these two-wheelers are supposed to be a necessary means of transport.

[pugram]

Originally Posted by Baristyro

Why are these BS6 bikes such wussies?! How did we come from an era where some bikes used to function completely normally without any battery, or without any fuel in the tank(fuel in the carburetor), to these dark times where one risks catastrophic failures by using all the fuel that they pay for. A double whammy for someone who lives paycheck to paycheck, for whom these two-wheelers are supposed to be a necessary means of transport.

I think the BS6 Era has bought about very finicky automobiles. There are lots of videos on YouTube and FB for BS6 issues of 2 wheelers and most of the are around the fuel pump. Dirty fuels and our dusty conditions seem to aggravate this further

[MT_Hyderabad]

Replace the spark plug and then see if the problem persists.

[aryangh21]

I have the same bike with the same issues. From what I have noticed, when the bike is parked in a way that causes fuel to flow towards the front, the bike refuses to start with 1 crank. When my bike is parked at my home it will start in 1 crank every time because the surface is perfectly level. But whenever I leave it at any sort of downslope it refuses to start in 1 crank. The problem seems to be getting worse day by day, so I suspect it is a dirty fuel filter but don't really know. The service center staff are clueless just like in your case but they haven't yet checked the fuel filter. If you find the solution please update the thread

[kaizengadi]

Originally Posted by boniver

Next time it refuses to start, try opening the fuel lid and closing it and then try to start the bike again. Worth a shot.

I second this, I have a pulsar 180 ver =. bs3, I used to face the same issue, the bike will refuse to start after parking in sunlight and the solution was to open the fuel cap and you will hear a pop sound like air escaping. The problem was with my fuel cap. After cleaning the lid and replacing the gasket it got resolved.

[Gautam_707]

I'm also facing the same issue from the beginning of my ownership for my FZS25. Amazing bike in all aspects except for some small niggles like this one. I have a feeling that my idle speed is too low though, so I'm going to try setting it higher, the company recommends higher than 1250 rpm at idle if I'm right. My theory is that since in the mornings we are performing a cold start, the fuel sent is automatically higher and the rpm is automatically higher too, so the idle speed theory makes sense. Although since the issue also crops up when starting the bike after a 20 minute break, but doesn't crop up when starting the bike immediately after turning off, your injector theory also makes sense.

[SatheeshBHP]

Originally Posted by SkylineGTR

I have a Yamaha FZ25 BS6 model, bought 8 months ago.

Originally Posted by pugram

I think the BS6 Era has bought about very finicky automobiles.

My 2014 FZv2 FI was fine till last few years. Now I have exact same problem like everybody here. I think this is issue is caused by ethanol blended petrol. I don't think this is because of BS6 vehicle.

Originally Posted by SkylineGTR

I will have to crank it 4 to 5 times in order to start the engine, sometimes by giving it some throttle (which is bad for FI vehicles)

Why do you think this is bad for FI vehicles?

Originally Posted by Gautam_707

Although since the issue also crops up when starting the bike after a 20 minute break, but doesn't crop up when starting the bike immediately after turning off, your injector theory also makes sense.

I think it is due to Engine temperature. Hotter the engine, difficult to start. I also noticed engine tends to stall randomly when idling at hot temperatures. Once on a very hot day, after heavy traffic, engine failed to start for more than 10 mins, So I poured 1 little cold water on the engine and it immediately started in single crank.

[Fastdriver]

Originally Posted by SkylineGTR

I have a Yamaha FZ25 BS6 model, bought 8 months ago. I have a rather strange issue with the bike: it will randomly fail to start on some occasions, behaving as if it has run out of fuel. I will have to crank it 4 to 5 times in order to start the engine, sometimes by giving it some throttle (which is bad for FI vehicle)

This is quite normal and happens to my FZ25 BS6 MotoGP edition also. I had the BS4 version also which got stolen but can't recollect whether this happened to that bike also. Any BS4 version owner's opinion is solicited.