Questionwrote to you yesterday and heres some more info for you with the original Q&A on the bottom!
Well i just bought this bike...rode it home which was about 30 miles or so...then next day rode it about 15 miles and the problems started...
It just started having problems shifting...basically while riding it all of a sudden was hard shifting up and almost impossible to shift down. It was like it just was reluctant to do anything. I pulled over right away and then once in neutral it didnt shift at all. The bike just didnt want to go into gear. Then to top it all off the battery just died and the bike wouldnt even start. I had someone come get me and i got the bike home and the dealer up and they said theyd come and get it in a couple of days. Meanwhile I was playing with it a little trying to get it to shift...and then the clutch cable came out of the lever...so I figured that was the problem...it just wasnt in right and was loose or something so the clutch wasnt engaging all the way making it not shift. The dealer guy came to get it and installed a new cable. I came and got it and rode it home again 30 miles and about 28 miles into the ride the bike had the same exact problem. It wouldnt shift down and then soon wouldnt shift at all. Then soon it wouldnt start either. Once i got it home and let it cool down it seemed sort of okay. Although i needed to push start it in order to get it going. But still it doesnt seem right and it makes like little crackling sounds. I dont wanna ride long or go far since I think that might be just asking for trouble. I was thinking whatever problem it is it has to do with the fact the bike has to be running awhile and get warmed up. So I dont know...Im only 19 and a newer rider so I'm not quite sure what the problem is or what I should do...any suggestions?
Subject 1992 honda cbr 600 f2
Question Well my bike is a 1992 honda cbr 600 f2. Its having some problems with the transmission. It rides fine when you first start it up, but once you ride for 30 or so minutes the bike starts acting up. Basically it wont shift properly. Its very difficult to get it to shift up and nearly impossible to shift down. Any ideas?
Answer Hi Kyle,
Q: "...It rides fine when you first start it up, but once you ride for 30 or so minutes the bike starts acting up. Basically it wont shift properly. Its very difficult to get it to shift up and nearly impossible to shift down. Any ideas?"
A: Yes, I have ideas of possible causes of the problem.
However, from the limited information provided I recommend that you have a local tech inspect the problem for accurate diagnosis.
Respectfully,
Mark Shively
AnswerKyle,
Thanks for the reply. I appreciate long, detailed narrative descriptions.
I cannot determine which, clutch or transmission, is the source of the problem. Both can produce similar symptoms when their systems become worn or defective.
I suspect the clutch needs attention.
Clutch systems are temperature sensitive. Metal clutch plates work at high temperatures. Friction between fiber and metal plates causes high temperatures as the plates transfers power from the crank, thru the clutch, to the transmission shafts. Metal plates can distort and warp and may cause the problems you're experiencing.
If the problem was not thermal related, I would suspect the trainy or a trainy linkage.
Get a copy of the service manual. Learn about clutch adjustment and clutch servicing. Inspect the clutch plates for wear. Inspect the clutch springs free length.
Note: Always replace fiber plates, metal plates, and clutch springs as a set. There are no exceptions.
FYI: I return tech files by email. There was no email address with your questions as requested and explained in my instructions. See sample files below.
Keep me posted on your progress (or lack thereof).
Respectfully,
Mark Shively
Sample tech files:
Definitions
Pressure Plate – The moving part of the clutch assembly that working against clutch spring tension, releases the clamping action on the clutch plates when the clutch lever is engaged.
Drive (friction) Plate – Consumable, fiber coated, ring-shaped friction surface that interfaces between the clutch basket tangs and pressure plate. Has tabs sticking out that match the cutouts between the clutch hub tangs and is coated with a friction material that vaguely resembles brake pad compound.
Driven (metal) Plate - Steel or aluminum ring-shaped disks that interface between the clutch hub and the friction plates. Steel plates are most often found in enduro/trail machines and provide longer wear and greater flywheel effect. Aluminum driven plates, near universally found in motocross type machines, are lighter, less durable and provide less flywheel effect. Additionally, aluminum driven plates wear out nearly as quickly as the friction plates themselves, in the process fouling transmission oil at an accelerated pace.
Clutch Springs – Short coil springs that continuously hold the drive and driven plates together through spring tension. Their duty is preventing slippage except when the clutch lever is engaged. Most often, five or more clutch springs are used per motorcycle clutch assembly. Firmer rated springs or more springs are typical of performance engines. Softer rate or fewer springs requires less clutch lever pulling effort.
Clutch Basket – A bowl-shaped gear-driven housing bolted onto the end of the clutch shaft that holds the entire clutch assembly.
Clutch Basket Servicing Procedure
Begin by either draining the motor's transmission oil, or lay a small bike over on its side, ISDE style (clutch side up). With the bike on its side, the oil doesn't need to be drained as it pools below the level of the clutch side cover. Next, remove clutch cover (on bikes so equipped) or the entire clutch side engine cover in order to expose the clutch basket. If the entire side cover must be removed, the kick starter, shifter and/or brake pedal might have to be removed first, depending upon the bike make and model (get a manual). Some models might even require the draining of engine coolant and/or disconnection of power valve linkage. Pray that your scoot has a clutch cover. With the clutch basket exposed, loosen the five or six fasteners on the face of the pressure plate that compress the clutch springs. In most cases M6-sized fasteners are used, most commonly shod with 10mm hex heads. On occasion you'll find an 8mm hex head or socket head (KTM) fastener. No matter which, back these bolts out evenly, a little at a time, alternating fasteners back and forth across the clutch basket. If the entire assembly has the tendency spin, drop the bike into gear to prevent this. With all of these fasteners completely loosened, lift out each bolt, washer and clutch spring and set them aside some place where they'll stay clean. Measure the free length of the clutch springs and compare that to the specification for minimum free length listed in your service manual. If the clutch springs have sagged, (insufficient minimum free length), they'll need to be replaced. With pressure plate retaining fasteners removed, the pressure, friction and driven plates may now be lifted out of the clutch basket. Remove the pressure plate first and set it aside with the clutch springs, someplace where it won't get dirty. When removing the pressure plate, be careful with the clutch actuation rod. Oftentimes there is a flat needle bearing, spacer, or even a simple ball bearing, that can drop out and become lost. Be sure to pay attention to the order in which these parts go back together. Be advised that for a basic clutch plate replacement, removal of the clutch actuation rod probably isn't necessary. However, while you've got things apart it's not a bad idea to check the rod for wear or bending, especially if clutch action has been faulty. Just be sure not to lose any of these small parts or forget how they came apart. Now it's time to lift out the friction and driven plates. Friction plates sometimes have the tendency to stick together, or even stick to the clutch basket face. A screwdriver or other prying tool can be carefully used to break the slight stiction holding them together. Be careful not to score clutch basket or clutch plate faces and stop immediately if they don't come readily apart—something must be wrong if that's the case, and you'll need to seek higher guidance. With all clutch plates removed, inspect the clutch basket, looking for grooves worn into the basket fingers or scoring on the face. Grooving adversely impacts clutch actuation effort and smoothness. If the clutch basket fingers are grooved more than, say, 1/32nd of an inch or so, they'll need attention. In extreme cases, the only option is replacing the clutch basket. However, if the grooving is less serious, they can be smoothed out using a hand file. Bear in mind though, this creates more slop in the clutch actuation, so that next time the grooving is likely to be considerably worse. Essentially, it's a temporary fix that buys you some additional riding time. Note that the clutch basket rides on one or two thin needle bearings. If you're forced to replace the clutch basket, its prudent to change this needle bearing as well. With all that out of the way, we can begin to reassemble things. If you're just replacing the friction plates, separate out the old friction plates from the driven plates. To replace the clutch, restack the new plates inside the clutch basket alternating friction plate/driven plate. A friction plate always goes in first, and as such all clutch assemblies always have one more fiber plate than metal plate. Be sure that a fiber plate is the last plate that goes in on the top of the stack as well. Do not stack the plates together dry—coat all of them with transmission oil before you stack them together, or you'll burn the clutch up the first time you ride the bike. If your bike is equipped with aluminum driven plates, its highly recommended that they be replaced, or at least checked during the replacement process. Again, your service manual will have a thickness specification for both friction and driven plates. If you're using your scoot for off-road racing or trail riding, we'd highly recommend you consider replacing aluminum driven plates with aftermarket steel ones. This switch offers three potential benefits to the typical off-road set: Better driven plate longevity (read: forever), less fouling of transmission oil, and greater flywheel effect. Continue the reassembly process by dropping in the pressure plate. Check your service manual, since some bikes require marks on the pressure plate and clutch basket to be lined up on reassembly. Begin to tighten it down by replacing the clutch springs and their fasteners. Be sure to start these bolts by hand to avoid cross threading them and hosing the clutch hub. Tighten them down evenly, alternating bolts in a cross wise manner. These bolts don't get torqued very much, so be sure not to manhandle or over-tighten them. There's a torque spec in your owners manual—use it. Complete the task by replacing the clutch cover or side cover with fresh gaskets. If you drained your oil, be sure to replace it with the proper amount of fresh transmission lubricant. We use Golden Spectro SAE 80w motorcycle gear lubricant in our two stroke gear boxes. In a four-stroke engine, remember to use a 10w40 or better motor oil rather than gear lubricant.
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Gear Shifting Faulty
Doesn't go into gear/shift pedal doesn't return:
Clutch not disengaging
Shift fork bent or seized
Gear stuck on the shaft
Gear position lever binding
Shift return spring weak or broken
Shift return spring pin loose
Shift mechanism arm spring broken
Shift mechanism arm broken
Shift pawl broken
Jumps out of gear:
Shift fork worn
Gear groove worn
Gear dogs and/or dog holes worn
Shift drum groove worn
Gear positioning lever spring weak or broken
Shift fork pin worn
Drive shaft, output shaft, and/or gear splines worn
Over-shifts:
Gear positioning lever spring weak or broken
Shift mechanism arm spring broken
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Clutch Operation Faulty
Clutch slipping:
No clutch lever play
Friction plate worn or warped
Steel plate worn or warped
Clutch spring broken or weak
Clutch release mechanism trouble
Clutch hub or housing unevenly worn
Clutch inner cable catching
Clutch not disengaging properly:
Clutch lever play excessive
Clutch plate warped or too rough
Clutch spring compression uneven
Engine oil deteriorated
Engine oil viscosity too high
Engine oil level too high
Clutch housing frozen on drive shaft
Clutch release mechanism trouble
Clutch hub locknut loose
