Check the engine idling speed.. I suspect the symptoms are pointing to that.
Get the idling speed increased and I believe the problem should go.


Cheers,

How is the throttle response?
Well, I have no experience but guessing may be due to a faulty O2 sensor or something.
Also is the engine overheating(any thing wrong with coolant/radiator)?

i don't know about r15 but today my byk faced a heavy rain again but i did not faced the problem today..may be luck..i tried that because when ever i am going out with my byke i am facing a rain now a days unfortunately.. currently i am owning fz-s

Spot on ...
The plastic piece is providing gap in the Fuel lid's sealing....be careful...better still remove it as it will allow rain water to enter the Tank....and your petrol tank will be flooded in due course of time
There will be breather system in tank cap through which the tank will be maintained at atmospheric pressure as you keep driving and petrol level keeps dropping..if this mechanism does not work then petrol tank will face mild vacuum as, petrol gets used up and petrol flow will get poor...I am not sure of the mechanism in R15..may be HarishK can help you...

+1 R15 also has the same mechanism a very little amount of air is allowed to enter the fuel tank via the Fuel cap to maintian the same atmospheric pressure within the tank to maintain the flow. By utilizing this pressure electronic Fuel pump does a great job in compressing the fuel and pushing it to the FI unlike carb'd bikes. (Process controlled by ECU)

Once while I was making some changes to the Airbox, I had to disconnect the fuel tank and place it on my car's seat for a while. I was foolish enough to place it sideways (Logo sticker down) coz was I was assuming that the fuel pump nozzle may get damaged. The fuel level was more than half tank, Result: A good amount of Fuel came out through the fuel cap and spilled on the seat. At first I thought my fuel cap was faulty, but after researching and asking experts, its the way the fuel cap is designed to maintain the same pressure within the tank, else the fuel flow and fuel gauge will not be accurate.

Why placing the plastic cover within the fuel cap? why not placing something above the cap? Just design a fuel tank cover or something which prevents water entering the fuel cap or simply buy a proper bike cover.

I guess his fear and problem was that he has no venting of tank and is also afraid that when he rides in heavy rain the water will get inside the tank, and the plastic sheet was used as a quick fix....
He needs to fix the Tank cap venting and ,he will be good to go.

using it while it is parking..not while i am driving..now does it make sense? can't carry bike cover while riding..so while parking the bike i am doing this covering? is it okay?

If you mean to say while riding your bike, water enters the fuel tank. Then get your fuel cap checked. The straight answer to your question NO DO NOT USE A COVER WITHIN THE FUEL CAP. It not only takes in some unwanted water into your fuel tank, also it affects the fuel flow and fuel gauge indication.

Not sure which genius gave you this idea, keep in mind you own a Yamaha and not a old wrecked truck that needs a cover to seal the fuel tank.

HAHAHHA,, LMAO


Dude, what you say might be right, this may help,thx


well, throttle Response is normal, i check silence;proper exhast pressure, throttle is also responsive

my bike is under shed so never faced direct rain


one more thing;i siphened out the entire fuel today , didnt found much water
i mean there may be 5 ml or so, and that too i suspect it must have come from within the bottle;
the fuel on the other hand smelled really bad; i felt like it was adultrated; can that be issue ?

Re: Yamaha R15 Engine Stalling

Re: Yamaha R15 Engine Stalling

I am repeatedly facing the same problem. I rarely ride during the first half of the monsoon (read heavy rains) and my bike stands under a cover. When the humidity and dampness is high and you ride after a break, I have noticed that the spark plug caps fail and this tak tak sound is heard. If you look carefully through the grill on the right side fairing you will notice sparking between the bottom half of the spark plug cap and the head of the engine coinciding with the tak tak sound. I have replaced about 4 spark plug caps so far in the last 4 years. I did not not loose any caps last year when i covered only the top of the petrol tank to instrument console area with a thick plastic sheet before putting on a cover that was well short of the ground to allow evaporation of rain water when the sun came out for brief spells, Another thing that sometimes did seem to help is to use a coat of clear nail varnish (polyurethane??) on the bakelite part of the spark plugs before fitting them to reduce moisture penetration. This is still under observation and strictly conjecture as of now. Surprisingly the new caps I get from the market have brass contacts instead of the silvery (silver plated??) ones I got earlier. Even the concentricity of the Spark plug cap is off centred. Quality degradation or fake is my question to the forum.

Re: Yamaha R15 Engine Stalling

I travelled to Kamla Yamaha and bought a pair of spark plug caps from them. They came with silver contacts and the rubber sleeves at both ends. They were perfectly concentric.
This means that there are fake components available at the two wheeler market with Yamaha style packaging complete with hologram. Beware friends.

Secondly, a good spark plug cap when measured across its contacts with an Ohm meter would give you about 4.8K as resistance.
A bad cap shows open or no conductivity.

Similarly a good Spark Plug should show ~ resistance (infinity) ie show no readable value after the display flickers on contact or shows "1". Continuity tester should not buzz.
As a spark plug ages and weakens, you will get a readable resistance in the 800 Ohms upwards range. Time to replace the plug.
A short plug shows little or no resistance.

Re: Yamaha R15 Engine Stalling

I am facing the same issue. Service center guys were the culprit, they adjusted valve clearance on a 1-2hour cold engine due to service rush.

Re: Yamaha R15 Engine Stalling [Solved]

Guys, my kawasaki boxer is facing somewhat same issues. This baby keeps stalling when I'm riding. Initially, I replaced the petrol tank on the mechanic's advice, said it was a bit rusted, then cleaned the carb, and the latest B. S. he gives me is that there is something wrong with the oil chamber. The problem still persists though. Help guys!!

Re: Yamaha R15 Engine Stalling [Solved]

Check the few item as follows and replace if necessary.
1. Spark plug/ spark plug adaptor or cap.
2. Choke cable.
3. Ignition coil and HT coil if needed.
4. Check the fuel tank breath hole. If it is closed due to rust and dirt the fuel won't be sucked in.
5. Replace the fuel filter if needed.
6. Check the air filter and make sure there is no presence of water inside or around it. It happens during rainy seasons. Even in Yamaha FZ. Lot of cases are been reported at our SVC.
Ride safe.