Experience difficulty starting my bike

[y0s_bikey]

Recently my bike is having problem firing up, in the past probably 1-2 sec on cranking and the bike is fired up. But now its really difficult to get it fired up, i need to crank a couples of times and each time at least like 4-6secs and it can as long as 10secs or more...

Anyone experience the same problem?
I am wondering could it be the Fuel Pump

Recently I have done some servicings:
- Flushed coolent and replaced with Mercedes Coolant
- NGK spark plugs replaced (original dual tip no more so I settled with the single tip. doubled check the model number same as the original stock)
- Agip Engine Oil and original oil filter changed

Current Mileage is 45,000KM

 

[RJ2112]

Recently my bike is having problem firing up, in the past probably 1-2 sec on cranking and the bike is fired up. But now its really difficult to get it fired up, i need to crank a couples of times and each time at least like 4-6secs and it can as long as 10secs or more...

Anyone experience the same problem?
I am wondering could it be the Fuel Pump

Recently I have done some servicings:
- Flushed coolent and replaced with Mercedes Coolant
- NGK spark plugs replaced (original dual tip no more so I settled with the single tip. doubled check the model number same as the original stock)
- Agip Engine Oil and original oil filter changed

Current Mileage is 45,000KM

45,000 kilometers in less than 2 years? :cheer::rockon::thumbup:

If it's getting hard to start, but runs well once it's warmed up, that often indicates the valve clearances are getting out of spec.

(even the 1-2 seconds you started with to get the engine running sounds like a long time, to me. Definitely, try timing it..... I bet it's quite a bit quicker than that.)

 

[y0s_bikey]

This is my Daily commuting vehicle as well as my touring buddy. Actually my bike is already 2 and half yrs old. I think alot of people are much much higher than me...

Thanks RJ2112, I am also thinking whether the valves are getting out... As I always hear this ticking sound coming under the tank when on the move, but when I clutch in the sounds disappeared...

 

[Bram]

This is my Daily commuting vehicle as well as my touring buddy. Actually my bike is already 2 and half yrs old. I think alot of people are much much higher than me...

Thanks RJ2112, I am also thinking whether the valves are getting out... As I always hear this ticking sound coming under the tank when on the move, but when I clutch in the sounds disappeared...

The ticking sound you hear, is this only in low RPM's at low speed?
I experience this ticking sound too.
My bike starts after 1.5sec when cold, and about 0.75sec when hot. Never had any problems starting.

 

[hazy]

Does our fuel injectors make tick-tick noise as well?

 

[Motogiro]

If this started after the bike was serviced you might pull the plugs and recheck the gap to see if they're all set to the proper specification. Bad gas could also be a problem.

 

[y0s_bikey]

Right after I install the plug, everything was still ok til recently I change the EO. But checking on the level, everything is fine. Probably will take out my plug tonight and check it out.

 

[RJ2112]

Right after I install the plug, everything was still ok til recently I change the EO. But checking on the level, everything is fine. Probably will take out my plug tonight and check it out.

I don't see any mention of replacing the air filter..... have you looked at that recently?

 

[y0s_bikey]

Oh I jus replace my K&N air filter to BMC air filter. So I don't think there should be any prob with the filter. As its new and clean.

 

[philosopheriam]

As an automotive mechanic, here are some things that can cause hard starts:

QUESTION:
Does the bike hard-start when it is cold or hot, or all the time?
Does the bike hard-start after it has been sitting a long time (overnight, 2 to 3 hrs, etc)?


You need to perform a fuel pressure test - attach a guage, and check to see if the proper pressure is building within the spcecified time period indicated in the FZ6 service manual. Also, check to see how fast the pressure bleeding down when the bike sits. If your pressure drops to near zero within 15 minutes, there's a problem....

Hards starts are *typically* caused by fueling issues:

1. Either the pump is getting weak and not building pressure fast enough, or it may not be building the proper pressure at all...

OR

2. The pump's inline check valve is going bad, causing the fuel pressure to bleed down over time (usually overnight or after 2 to 3 hrs).

OR

3. An injector could be leaking after shutdown, causing a flooding and low fuel pressure condition. This hard-start usually shows up when the bike is hot, simply because the extra fuel in the cylinder is too rich for the engine temp. I've diagnosed vehicles that have leaky injectors that will start fine when cold, yet crank for 5sec or more when hot (After they have been sitting for at least an hr).

Just some food for thought - these situations need to be approached methodically - simply replacing random parts is a quick way to waste money.

Also, I encourage you to replace your plugs with the original NGK, dual-tip CR9EK - your engine was designed to have a dual-tip plug, and the design of a plug can significantly impact ignition and combustion. In this instance, don't try to outsmart the Yamaha engineer....

 

[philosopheriam]

Also, keep in mind that the above list is not exhaustive - there are a bunch of other things that can cause hard starts - engine cranking speeds, overall compression, weak spark, etc. However, fueling is the FIRST thing a mechanic looks for when diagnosing hard starts.

 

[y0s_bikey]

As an automotive mechanic, here are some things that can cause hard starts:

QUESTION:
Does the bike hard-start when it is cold or hot, or all the time?
Does the bike hard-start after it has been sitting a long time (overnight, 2 to 3 hrs, etc)?


You need to perform a fuel pressure test - attach a guage, and check to see if the proper pressure is building within the spcecified time period indicated in the FZ6 service manual. Also, check to see how fast the pressure bleeding down when the bike sits. If your pressure drops to near zero within 15 minutes, there's a problem....

Hards starts are *typically* caused by fueling issues:

1. Either the pump is getting weak and not building pressure fast enough, or it may not be building the proper pressure at all...

OR

2. The pump's inline check valve is going bad, causing the fuel pressure to bleed down over time (usually overnight or after 2 to 3 hrs).

OR

3. An injector could be leaking after shutdown, causing a flooding and low fuel pressure condition. This hard-start usually shows up when the bike is hot, simply because the extra fuel in the cylinder is too rich for the engine temp. I've diagnosed vehicles that have leaky injectors that will start fine when cold, yet crank for 5sec or more when hot (After they have been sitting for at least an hr).

Just some food for thought - these situations need to be approached methodically - simply replacing random parts is a quick way to waste money.

Also, I encourage you to replace your plugs with the original NGK, dual-tip CR9EK - your engine was designed to have a dual-tip plug, and the design of a plug can significantly impact ignition and combustion. In this instance, don't try to outsmart the Yamaha engineer....

For cold start, I have no problem starting the bike. It only happens when i stop for awhile like for a meal or something like that.

As for the dual tip thing, I have no choice. Previously I got it from that shop and they told me that there is no more dual-tip. Now new stocks all come in single tip, of cos I would rather get back the dual-tip. Probably I should check with NGK. by the way thanks for the infos!

 

[philosopheriam]

For cold start, I have no problem starting the bike. It only happens when i stop for awhile like for a meal or something like that.

First, verify that your coolant temperature sensor is reading accurately - if it's reading at a falsely low temperature, it can cause the ECU to start the engine with too rich of a fuel mixture.

To properly diagnose your problem, a fuel pressure test is definitely in order - hook up an adapter between the pump and the fuel rail (a line tap in the pressure line), turn on the ignition, disengage the kill switch, let the pump prime, and measure the pressure - it should be at least 36 psi withing 2 to 3 seconds (running pressure of the fuel system). Start the engine and record the pressure, it should be around 36 psi. Then, shut the engine off and record the time/amount of any pressure drop. A large pressure drop after the bike has been sitting a while is indicative of a problem.

Hot start issues are often linked to leaking injectors...