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Discussion Starter #1
2009 V-Star 1300, 13.5k mi, I've put 3200 trouble-free miles on the bike since January.
So, I had been riding on the highway at 80+ for 40 miles. Got off on the State Road, traffic lights about every mile or two.

After about 3 miles, cruising 50mph, the power starts decreasing. Increasing throttle maintained speed for about 5 seconds. Over the next five seconds, power continues to drop off. Opening throttle generates a little more power, but very little.
I pull the clutch to maintain the speed I have, and the engine spins down to zero. Fully open throttle does not keep the engine running.

Coast off to the side, kickstand down. No warning lights (maybe oil pressure, can't remember). Certainly no Check Engine Light.

Turn the key off for about two seconds, than back on. Needles sweep, etc, all normal. No CEL. Hit the starter. She starts right up.
Rode her to my meeting (another 2 miles), then home 45 miles (at 80+). No issues.

Anyone seen this behavior? It's troubling, I'm not sure what to think about it.
(PS, I did search, nothing about this behavior came up).

Thanks!
 

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2009 V-Star 1300, 13.5k mi, I've put 3200 trouble-free miles on the bike since January.
So, I had been riding on the highway at 80+ for 40 miles. Got off on the State Road, traffic lights about every mile or two.

After about 3 miles, cruising 50mph, the power starts decreasing. Increasing throttle maintained speed for about 5 seconds. Over the next five seconds, power continues to drop off. Opening throttle generates a little more power, but very little.
I pull the clutch to maintain the speed I have, and the engine spins down to zero. Fully open throttle does not keep the engine running.

Coast off to the side, kickstand down. No warning lights (maybe oil pressure, can't remember). Certainly no Check Engine Light.

Turn the key off for about two seconds, than back on. Needles sweep, etc, all normal. No CEL. Hit the starter. She starts right up.
Rode her to my meeting (another 2 miles), then home 45 miles (at 80+). No issues.

Anyone seen this behavior? It's troubling, I'm not sure what to think about it.
(PS, I did search, nothing about this behavior came up).

Thanks!
I had the same thing happen once, but I figured it out before I came to a stop, my thumb it the kill switch. Sounds silly but one complaint about the 1300 is the kill switch is a little easy to accidentally hit.

If that wasn't it, could be a loose wire connection. BTW the throttle mapping doesn't get corrupt and then fixed again by re-starting the bike so I doubt that is it. The TPS (Throttle position) sensor also could be flaky or have a bad connection as well
 

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this is one of the tradeoffs of fuel injection vs carbs. If any one of your sensors quits or becomes intermittent the engine runs poorly or not at all.

Intermittent issues are very difficult to trace down.

If the bike continues to do that at random the only way I know to fix it is to:

1. start checking all the connections and wires to the sensors
2. start swapping out the sensors one by one until the fault goes away.
 

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Logical: Like KCW said.... Check all connection and wires to sensors. While checking connections, make sure the grounds are good and seated well on the bike.


Illogical (but funny): Do you have any enemies? Any "friends" have access to an EMP and they 'blasted' you?
 

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Discussion Starter #6
this is one of the tradeoffs of fuel injection vs carbs. If any one of your sensors quits or becomes intermittent the engine runs poorly or not at all.

Intermittent issues are very difficult to trace down
Thanks guys. That's what I figured, but was hoping that there was a "known issue" that would simplify things.

If it happens again, I'll update.
 

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BTW the throttle mapping doesn't get corrupt and then fixed again by re-starting the bike so I doubt that is it.
maybe not, but why do people claim that you can reset it by disconnecting the battery for a short time? i've seen this claim on multiple forums but haven't seen anyone cite any evidence.
 

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BTW the throttle mapping doesn't get corrupt and then fixed again by re-starting the bike so I doubt that is it.
maybe not, but why do people claim that you can reset it by disconnecting the battery for a short time? i've seen this claim on multiple forums but haven't seen anyone cite any evidence.
Is there any cached memory in the throttle mapping?
If the answer is yes, then the reason why disconnecting the battery works is that it resets to the last known good configuration. Same way the battery from a laptop or power cord from a work, hold the power button for 15 seconds clears the cache from the bios & removes any residual power that is "saving bad memory".
If the answer is no, I would have to research to find the correct answer.
 

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the VS 1300 service manual should have one of those fault debugging trees.

If you are not getting any faults blinking the check engine light, then the ECM is being completely swamped by the fault condition, to the point of cutting off the fuel or ignition, or flooding the fuel so bad the engine wont fire.

I dont know if the 1300 service manual is available online - I know the 650 service manual is.
 

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Discussion Starter #10
If you are not getting any faults blinking the check engine light, then the ECM is being completely swamped by the fault condition, to the point of cutting off the fuel or ignition, or flooding the fuel so bad the engine wont fire.
That's exactly what got my attention, that there were no CEL lights, blinking lights, or anything.

Troubleshooting is always fuel, air, spark.
My first thought was fuel starvation (filter or pump), but after 40mi of 80+mph, a problem should have presented itself on the highway rather than at cruising at 50mph.
Second thought was air, but for the same issues, it didn't seem likely (and there's a 30 day old air filter in there).
Spark didn't seem likely, as the bike was running perfectly smooth, just felt like I rolled off the throttle. It was smooth all the way to shutdown.

I looked in the tailpipe with a light, and didn't see any blockage. One very bad thing with airplanes is getting a loose baffle that blocks the exhaust and chokes the engine.
That would seem to make sense in that after the engine quit, the loose baffle had pressure removed and fell away from where it was blocking. That would also explain no CEL, in that the engine management is doing everything right, there just is too much backpressure.
But I don't know how MC mufflers are made and whether than can actually happen. The exhaust is factory, and not drilled.
 

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even though the bike is 8 years old, with only 13k miles on it nothing mechanical should be failing, like the exhaust baffles.

One of the most common failures on MCs is the ground wire from the battery where it attached to the frame. People pay attention to the battery terminals because the battery gets changed every 4 years or so, and the positive connection into the fuse box and the starter is usually copper to copper, or tinned connectors into tinned connectors...

but the battery ground wire to the frame is copper or tinned terminal to the steel frame of the bike. Its usually where you cant see it, so people dont notice it gets corroded - and when you lose that side of the battery many weird things can happen.

If you cant find a bad connection somewhere I'd keep riding the bike and see if it happens again.
 

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Discussion Starter #12
One of the most common failures on MCs is the ground wire from the battery where it attached to the frame. ... and when you lose that side of the battery many weird things can happen.
Of course you are right, weird electrical behavior always starts with checking battery health and ground. And with a fuel injected bike, the engine is an electrical component. I just wasn't thinking that way.

Thanks for the reminder.
 
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