Technical: Cush Drive on 2008 Ex250R

[Sailariel]

In 5500 miles I am in my second cush drive, The second drive has developed a slop where the chain actually causes a chattering action, particularly when you decellerate and again accelerate. The service manager is stumped. My bike will go into the shop this Monday and will be torn apart. On Tuesday a factory rep will be on hand to check the situation out. I was assured that the problem will be taken care of even if it meant a new bike. The service manager said that mine was the only 250 that to his knowledge has had that problem. I expect the problem to be solved. There is nothing more frustrating than negotiating a twistie and having your drivetrain chatter. My view is that it is their (Kawasaki`s) issue to solve. My present--the second cush drive has two inches plus of slack. The service manager feels that there is some manufacturers defect that is causing the problem. Will keep you all posted on th results. He suspects an alignment problem that causes the abnormal wear. I pointed out that the sprockets show a wear pattern that does not look right to me (I am a certified bicycle mechanic and know a lot about reading chain rings--after all I deal with 30Speed Derailleuer systems every day) I expecy that Kawa will find an equitable solution.

[kkim]

you do realize this problem has been around since the pregen days?

mine is developing some chain snatch at off/on throttle when cruising in 6th gear. I've just been too lazy to pull the wheel and shim the cush drive.

[Sailariel]

Kelly. I`ll be interested to see what Kawa sees as the solution. The ball is in their court. I did broach the subject of shimming with him. He says that this is not a Kawa approved solution. Will definitely keep you informed. I do know that it took Suzuki a couple of years to solve the problem on their `Busa.

[kkim]

lol... it's been over 20 years with the pregens having this same problem. If Kawi didn't address it on the redesign, I doubt they will have an engineered fix for this at this time. I will hope for the best, though, and see if they prove me wrong.

My best guess is that they will either replace the cush you have with another unit that will develop the same slop over time or end up shimming it.

[Alex]

Can you explain in a little more detail what you mean by "chattering"? I'm having a hard time understanding exactly what the problem is. The cush drive doesn't fit perfectly, and over time it compresses and allows the sprocket to move around a little bit more, but as far as I can tell all that does is cause slightly more drivetrain lash. The ninjette has so little lash compared to many other bikes that I don't notice it all on our machine, probably because the gears in the transmission can be a lot finer on a bike with 15 pound-ft of torque and don't need as much slack. Is the cush drive actually falling apart on the bike, or is it just compressing a little over time?

[kkim]

Originally Posted by Sailariel

My present--the second cush drive has two inches plus of slack.

That's a lot of slack.

[Alex]

I see that now, but I don't understand how 2 inches of slack is even possible. If you take the rubber piece completely out and just have the metal sides of the cush drive left, the sprocket still can't move two inches in any direction without hitting one of those stops, right? There's gotta be something here that I'm not understanding...

[kkim]

yeah, I guess we'll have to wait til they take Alex's bike apart to investigate.

Alex- How are you measuring the 2"?

[Sailariel]

Alex, The two inches represents how far the bike can move forward and back when first gear is engaged (engine off, of course) When I ride in traffic--very slowly in second and third gear, there is a distintive chattering noise, especially (as Kelly said) in a throttle on and off scenario. The service manager agreed that a certain amount of slop will invariably ocurr with normal wear and tear--and that is acceptable. However, two cush drives in 5000 miles is, in his view, not acceptable. Everything from the swing arm, including the swing arm. back is suspect. The game plan is to take the back out of the machine and to examine each piece very carefully. Anything out of spec. will be cheerfully replaced. The swing arm could have been bent during initial assembly. The cast aluminum wheel could have a slight abnormality. Something, or a combination of some things is causing the problem. It could be a simple thing or something more complex. We will find out. I did take an 09 EX 250 for a ride, and it did not demonstrate that ideosyncracy. The service manager did the same. We are definitely on the same page.

[Sailariel]

I got the bike back and we are on our third cush drive in 6200 miles. Kawa thinks that this is all a figment of our imagination. They did not send a rep--they simply chose to adress the issue by phone. The Service Manager at Friend and Friend is considered one of the best mechanics in Maine. He and I deduced that there are three, and only three, things that can cause that extreme sort of drivetrain lash--Too small rubbers in the cush drive, a casting in the wheel that was defective and was not caught by quality control, or the casting for the drum that mounts the sprocket for the same reason. We have eliminated the possibility of the rubber dampener being defective. That leaves the two other items. Kawasaki is unwilling to send a new wheel and drum so that the problem could be solved. The only recourse I have is to call Customer Service. explain the problem, and see what they say. If there is no cooperation on that end, I plan to sue Kawasaki under the State of Maine Lemon Law. I don`t think that they will want that sort of publicity for something they can solve cheaply and quickly. The ball is in their court. They may play the "deeper pocket" game, but I think that they will quickly learn that they are up against a Pit Bull and that this year long charade that I have put up with is getting a bit old. I still have two years of warranty. I also have two certified motorcycle mechanics that will attest to the fact that this degree of drivetrain lash affects the longevity of the chain and sprockets. Kawasaki claims that drivetrain lash is not a problem with their EX250 machines. Well, my machine has that problem, and they damn well should deal with it. Besides, a bike that bucks like a bronc when you decelerate and again accelerate is dangerous--especially in the wet. Will keep you posted.

[Alex]

Alex - what happens if you tighten the chain to almost no slack (say 1/4 inch or so max), and then see how much drivetrain lash you feel when rolling the bike forward and back. Once the test is over return the chain slack to the normal 1.5 inches.

When the chain slack is set as recommended, being able to roll a bike 2 inches forward and 2 inches back while it is in gear is completely normal, and not evidence of any problem at all. I think it's unlikely that a new sprocket drum or wheel will have any effect on what you think you are feeling. Bikes have lash, they all do. Some ninjette owners shim the cush drive to take a little of that lash feeling out of it, others don't mind it in the least.

I hope this is eventually resolved to your satisfaction, but if Kawi believes there isn't an issue with your bike, the lemon law will most likely not be successful for you. Check out what the Maine lemon law specifically states:

http://www.carlemon.com/lemon/ME_LemonGuide.html

D. What Problems are NOT Covered by the Lemon Law?
The Lemon Law does not cover vehicles with the following types of problems:

1. defects which do not substantially impair the vehicle's use, value, or safety;
2. defects caused by owner negligence;
3. defects resulting from accident, or vandalism;
4. defects resulting from unauthorized repair of the vehicle by a person other than the manufacturer, its agents or authorized dealers

and

F. What is Substantial Impairment?
The Lemon Law only covers serious defects - those which substantially impair the use, safety or value of the vehicle. However, the law does not list specific defects which are considered substantial. You must be able to demonstrate how your vehicle has been substantially impaired. For example, to prove substantial value impairment, you could show that the retail value of your vehicle is significantly less than it would be without the defect. Although a defect may be annoying, it is not necessarily "substantial".

I don't think drivetrain lash counts as substantial, especially if it is not unique to one particular instance of a motorcycle, but is similar on all of them. I know that you probably would feel it is substantial. I have a feeling I also know which side Kawi would come down on this.

If you really want this fixed, if it is in fact even fixable, I think you'll be more likely to get to an outcome you'd want without threatening the mechanic, the dealer, or kawi corporate with a lemon law claim. At that point they immediately have zero incentive to help a disgruntled customer, and their legal staff tells the dealer to stop returning your calls.

[randomwalk101]

never back down..it's the principle...gotta fight for your rights. Never let big corp walk all over you!!!

[Sailariel]

Originally Posted by Alex

Alex - what happens if you tighten the chain to almost no slack (say 1/4 inch or so max), and then see how much drivetrain lash you feel when rolling the bike forward and back. Once the test is over return the chain slack to the normal 1.5 inches.

When the chain slack is set as recommended, being able to roll a bike 2 inches forward and 2 inches back while it is in gear is completely normal, and not evidence of any problem at all. I think it's unlikely that a new sprocket drum or wheel will have any effect on what you think you are feeling. Bikes have lash, they all do. Some ninjette owners shim the cush drive to take a little of that lash feeling out of it, others don't mind it in the least.

I hope this is eventually resolved to your satisfaction, but if Kawi believes there isn't an issue with your bike, the lemon law will most likely not be successful for you. Check out what the Maine lemon law specifically states:

http://www.carlemon.com/lemon/ME_LemonGuide.html



and



I don't think drivetrain lash counts as substantial, especially if it is not unique to one particular instance of a motorcycle, but is similar on all of them. I know that you probably would feel it is substantial. I have a feeling I also know which side Kawi would come down on this.

If you really want this fixed, if it is in fact even fixable, I think you'll be more likely to get to an outcome you'd want without threatening the mechanic, the dealer, or kawi corporate with a lemon law claim. At that point they immediately have zero incentive to help a disgruntled customer, and their legal staff tells the dealer to stop returning your calls.

Alex,I totally agree with you. Lemon Law would be the ABSOLUTE last resort. The Service Manager at the dealer is absolutely first rate. He is competent, very professional, and a very accomplished rider. (He races a Suzuki `Busa) He is on record as to the problem and has said many times that this is not normal for this machine. He is still argueing wit the Warranty Division. Riding their 09 250 Demo really brings out the difference. We are not talking Rocket Science---simply, excessive lash which could be dangerous in a cornering situation--especially in the wet. My friend,,the Ducati dealer, also feels that there is a problem. The service manager and I have decided to pursue the shim route if Kawasaki does not send a wheel and sprocket drum. We do need to ascertain whether it would void the warranty. Rest assured that I am not a confrontational type, and am not particularly fussy, but this problem has existed since day one, and I would like to see it brought to some sort of conclusion. I plan to call Customer Care on Tuesday and ask them for some help. I suspect that they will make some calls, probably talk to the service manager--or maybe even my friend at the Ducati shop. I guess we will wait and see. In the meantime the bike is ridable and we are enjoying some great weather. Again, Alex, thanks for your good advice

[Alex]

I really appreciate that post, Alex. I was hesitant posting up because I didn't want to seem unsupportive, and if you and the service manager are both completely confident that something is wrong with your particular bike that isn't exhibited on other ninjettes, even with all the adjustments (chain slack primarily) identical, I hope you're both able to put your finger on what the actual issue turns out to be.

When you mention the chattering, is that under a constant throttle, or are you talking about what happens if you roll off the throttle slightly, then roll it back on?

[HKr1]

Originally Posted by Alex

but I don't understand how 2 inches of slack is even possible. If you take the rubber piece completely out and just have the metal sides of the cush drive left, the sprocket still can't move two inches in any direction without hitting one of those stops, right? There's gotta be something here that I'm not understanding...

Those rubbers are Kinda big, maybe 1" each at the top edge(and theres two in each slot).

Took .125 of a shim to take up 1/2" slop @ the sprocket in ours.

[Alex]

That's pretty much what I thought. I don't believe that shimming the cush drive accomplishes nothing at all, but I didn't see how it could take up 2" of slack in each direction.

[HKr1]

^ They shouldnt be sloppy For 2 inches of slop, they must be missing all together.

[Sailariel]

Originally Posted by Alex

That's pretty much what I thought. I don't believe that shimming the cush drive accomplishes nothing at all, but I didn't see how it could take up 2" of slack in each direction.

The slack I am referring to is the movement of the bike forward and back while it is in gear--Two inches forward and two inches backwards. The chatter is a shuddering vibration that happens when I let up on the throttle and accelerate again. This happens in all the gears--very appearent in sixth at a low RPM. I now shift down to third or fourth where the shudder is not as annoying.

[Sailariel]

Originally Posted by Alex

I really appreciate that post, Alex. I was hesitant posting up because I didn't want to seem unsupportive, and if you and the service manager are both completely confident that something is wrong with your particular bike that isn't exhibited on other ninjettes, even with all the adjustments (chain slack primarily) identical, I hope you're both able to put your finger on what the actual issue turns out to be.

When you mention the chattering, is that under a constant throttle, or are you talking about what happens if you roll off the throttle slightly, then roll it back on?

The manager and I both feel that since both the wheel and the sprocket drum are cast aluminum, there is the possibility that either the drum or wheel could have been a bad casting that was missed by quality control. We would like Kawa to send the dealer a new wheel and drum. We could try the drum first and see what happens. We could then try the new wheel with my drum and see what happens. It is basic deductive diagnostics. We will send them back what we don`t use. We have ruled out the rubber cush drive. The one that Kawa authorized to change looks like new. I have it as a spare. That leaves the wheel and the drum. Changing the cush drive changed nothing. I could accept this as a ninjette idiosyncracy were it not for a short ride I took on one of the dealer`s ninjettes. That bike did not exhibit any of those symptoms. I`ll call Customer Service on Tuesday and seek their advice. I plan to be totally diplomatic. I do like the bike a lot. I think it is well made, a real knockout stylingwise, and a damned rocket for a 250. I don`t think there is a 250 on this planet that can top it`s performance unless you have a factory racer. It is probably the closest thing to a street legal racer around. If they decide to do nothing, I still have two years on the warranty. I will probably fabricate a nice set of shims made from aluminum beer cans--will have to sample the beer first. Will also do a DIY. I plan to buy a 10 Megapixel camera soon and give Sunny some competition. The transition from 35mm to Digital is not as easy as I thought. Right now I have to get through this eye surgery in July before I do any precision work.

[Sailariel]

Problem Solved: Decided to go the shim route. I used a plastic "For Sale" sign and cut 12 2X3.5Cm rectangles.The thickness was 1.5mm. These rectangles were attached to the rubber damper with a small drop of Super Glue after the rubber damper was thoroughly cleaned with Isopropyl Alcohol. After everything dried,I reassembled the whole thing as per the Service Manual, paying special attention to chain tension, wheel alignement, and the torque specified for the rear axle. It is like a different bike (The driivetrain lash was there since day one) There is no noise, no chatter, and no lash when decellerating and accelerating again. I am very pleased with the results. I decided not to make a warranty issue out of this problem, since I could fix it myself. I felt that the good relationship I have with the best service manager in Maine was not worth jeopardizing over something so Mickey Mouse. Better I save the warranty for something that is really bad. Anyway, I took the bike out for a test ride and it was---like the kids today say, AWESOME! I also have a spare cush drive in mint condition. Life is good.