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6 Posts
Okay, I have a doozie here.. I'm hoping that a.) someone has heard of or had this happen to them, and b.) I can explain it properly so that a. is true.
My bike is a 2007 Ninja 500.
I had a BUNCH of work done on my bike within the past 6 months.. long story short, lady backs into it, dings it up real good (cosmetic scratches only, nothing mechanical damaged), i use the insurance $ to fix it up differently than insurance intended.. I replaced the damaged stock exhaust with a Muzzy. Had a jet kit installed. New spark plugs, new chain, new K&N air filter, had the valve clearance checked. New cush bearing thing (forget the technical term), new rear wheel bearings, new tires. Cables lubed. Umm.. I think that's it.
So here's my problem.
Upon reception of my new hotness bike, it's had a chronic and predictable problem that the bike shop has yet to properly troubleshoot.. and I know for a fact this problem did not exist prior to their work. Upon acceleration, the engine hesitates. More specifically, specific levels of acceleration cause what feels like a 'muddying up' of the gas/ignition process, causing stuttering and what I affectionately call "spluttering".
I'll try to explain further, as I'm not a mechanic, so forgive me if I don't provide enough or the wrong details.
So in the morning, I start up the bike. I choke it out and get the idle up high. No spluttering. I let it sit for about 60-120 seconds like that until the idle evens out, then I drop it down to raw idle. I let it sit for another minute or two, then I take off. As I drive away, I can open the throttle _very_ slightly, like a grandma opening a jar of peaches, and no splutter. The moment I open it to a certain point, let's say 20%, it hesitates and starts to splutter. It will lag and at times, slow down. Kinda sounds like I have water in my gas. Or peaches. If I let off the throttle just a hair, it goes normal. I can go back and forth, and it's repeatable. It's as if there is an invisible line that I can cross that causes this problem, and it exists at any speed, in any gear, and at any temperature, but only with specific levels of throttle. I find it significant that it does not do this with any amount of choke that I apply.
If I open the throttle up to, let's say 80% and above, the spluttering ceases instantly and I really get moving. So at near-idle, it performs nominally. At near wheely, it performs as I'd expect. Anywhere in the middle, horrid.
The bike shop thinks that it's too lean, or too rich, and that this is to be expected in the colder weather (as it's sept, and beginning to chill.) It is indeed more noticable in the colder mornings, but it does not get better no matter how long I ride, or even if it warms up to 80+ in the afternoon. This is a very constant and predictable thing, it NEVER just goes away, and the performance can be so bad (if I hold the throttle in the 'dead zone') that it can sometimes strangulate the engine, and I have to start it up and ease back into it to make it recover.. like it's gasping for air, while I look around and feel like a tool on my crippled ride.
I have a hard time believing that, by installing a new exhaust and a jet kit, I am doomed to live with this performance. I understand where the gas mixture ratio seems like a fairly logical answer, but I'm doubting it now, as the mechanic has adjusted it 3-4 times and there has been no change, no improvement. If I could imagine what it looks like in the carb, it's like at certain volumes of gas, the would-be spray turns into a "splutter" of gas, instead of the atomized mist that it should be. And at higher levels, it returns to a mist and zoom, away I go. Like there's something wrong with the 'vaporizers', whatever they are called. Or maybe spark plugs? Timing? A facial pube of a mechanic permanently immortalized inside the carb needle?
Would some other thing cause this type of performance, or otherwise mislead professional automotive technicians into believing it's a gas mixture problem? Or is this really and truly a symptom of what happens when one installs a muzzy exhaust and a jet kit (not a racing-stage kit, I think it was like 0 or 1, just a standard street kit, whatever rating that is) into their ninja. Honestly, if this is how it is, then I may either request to have the jet kit removed, or else I'm going to sell the bike, because it's become embarassing and really un-fun to drive around and sound like I use vanilla pudding for fuel.
What do you all think? Any help or advice that I can throw back at the mechanics and say 'neener neener' would be GREATLY appreciated!! :thumb:
My bike is a 2007 Ninja 500.
I had a BUNCH of work done on my bike within the past 6 months.. long story short, lady backs into it, dings it up real good (cosmetic scratches only, nothing mechanical damaged), i use the insurance $ to fix it up differently than insurance intended.. I replaced the damaged stock exhaust with a Muzzy. Had a jet kit installed. New spark plugs, new chain, new K&N air filter, had the valve clearance checked. New cush bearing thing (forget the technical term), new rear wheel bearings, new tires. Cables lubed. Umm.. I think that's it.
So here's my problem.
Upon reception of my new hotness bike, it's had a chronic and predictable problem that the bike shop has yet to properly troubleshoot.. and I know for a fact this problem did not exist prior to their work. Upon acceleration, the engine hesitates. More specifically, specific levels of acceleration cause what feels like a 'muddying up' of the gas/ignition process, causing stuttering and what I affectionately call "spluttering".
I'll try to explain further, as I'm not a mechanic, so forgive me if I don't provide enough or the wrong details.
So in the morning, I start up the bike. I choke it out and get the idle up high. No spluttering. I let it sit for about 60-120 seconds like that until the idle evens out, then I drop it down to raw idle. I let it sit for another minute or two, then I take off. As I drive away, I can open the throttle _very_ slightly, like a grandma opening a jar of peaches, and no splutter. The moment I open it to a certain point, let's say 20%, it hesitates and starts to splutter. It will lag and at times, slow down. Kinda sounds like I have water in my gas. Or peaches. If I let off the throttle just a hair, it goes normal. I can go back and forth, and it's repeatable. It's as if there is an invisible line that I can cross that causes this problem, and it exists at any speed, in any gear, and at any temperature, but only with specific levels of throttle. I find it significant that it does not do this with any amount of choke that I apply.
If I open the throttle up to, let's say 80% and above, the spluttering ceases instantly and I really get moving. So at near-idle, it performs nominally. At near wheely, it performs as I'd expect. Anywhere in the middle, horrid.
The bike shop thinks that it's too lean, or too rich, and that this is to be expected in the colder weather (as it's sept, and beginning to chill.) It is indeed more noticable in the colder mornings, but it does not get better no matter how long I ride, or even if it warms up to 80+ in the afternoon. This is a very constant and predictable thing, it NEVER just goes away, and the performance can be so bad (if I hold the throttle in the 'dead zone') that it can sometimes strangulate the engine, and I have to start it up and ease back into it to make it recover.. like it's gasping for air, while I look around and feel like a tool on my crippled ride.
I have a hard time believing that, by installing a new exhaust and a jet kit, I am doomed to live with this performance. I understand where the gas mixture ratio seems like a fairly logical answer, but I'm doubting it now, as the mechanic has adjusted it 3-4 times and there has been no change, no improvement. If I could imagine what it looks like in the carb, it's like at certain volumes of gas, the would-be spray turns into a "splutter" of gas, instead of the atomized mist that it should be. And at higher levels, it returns to a mist and zoom, away I go. Like there's something wrong with the 'vaporizers', whatever they are called. Or maybe spark plugs? Timing? A facial pube of a mechanic permanently immortalized inside the carb needle?
Would some other thing cause this type of performance, or otherwise mislead professional automotive technicians into believing it's a gas mixture problem? Or is this really and truly a symptom of what happens when one installs a muzzy exhaust and a jet kit (not a racing-stage kit, I think it was like 0 or 1, just a standard street kit, whatever rating that is) into their ninja. Honestly, if this is how it is, then I may either request to have the jet kit removed, or else I'm going to sell the bike, because it's become embarassing and really un-fun to drive around and sound like I use vanilla pudding for fuel.
What do you all think? Any help or advice that I can throw back at the mechanics and say 'neener neener' would be GREATLY appreciated!! :thumb:
