Hey everybody, so i wasnt able to get a solid answer anywhere about my crank play problem so i gave in and bought a wiseco crank kit as well as a piston kit while im in there. just thought id let everyone know how i got about doing it. i know im gonna get a lot of yelling at for this but i DONT have a service manual, so hopefully ill do it right. please feel free to correct anything that i may have missed or did improperly. on a side note, the CRF compared to other bikes is actually quite accesible and forgiving to work on, even compared to some two strokes IMO. the disassembly (with patience) so far has gone quite smoothly, im looking forward to assembly.
so first off here are some of the products i bought to do the job:
iv got my crank kit, piston kit, clutch kit, timing chain, and some other things that arent detrimental to a bottom end rebuild.
so hopefully ive got everything... unless i break something while dissassmbling
, just have to be patient, so start stripping the bike down (plastics, muffler, gastank, subframe, and airbox, kickstarter lever, rear brake foot lever and drain the fluids.
clean the motor with engine cleaner and a tooth brush to get into tight places, i also had a vacuum cleaner handy to clean some dirt from recesses in the engine (spark plug hole etc...) so anyway, after it was relatively clean and the motor accesible i got to work taking off the right side engine cover (the cover on the clutch side). remove all the 8mm engine cover bolts and make sure that you get them ALL! dont force the case to "break free" it should come off with relative ease
as many of you allready know, this is the right side of the engine with the cover removed... what i noticed (and am not completely sure of) is the markings on the gear wheels, refer to next pic.
Like i said, i dont have a service manual so i took special interest in this. correct me if im worng but it seemed to me that when the dimples on the inner gears (i think they have the same amount of teeth) line up, the motor is at TDC and the counter balancer shaft is at its lower position as in the pic below. what i was wondering is why there is a dimple on the second (smaller) gear on the crankshaft? (maybe just to line up to the case dimple in the case?) on the flywheel side its pretty simple to remove the cover just remember to unplug and free up the wireing that goes to the cover, and be mindful that the stator is mounted ON the cover itself. if a pic is required i can provide.
anyway, so this is the position of the counterbalancer when the motor is at TDC and the dimples on the opposite side (of engine) gears line up.
The next step was to get all the bolts and nuts loose on the crank gear, flywheel, sprocket, counterbalance shaft... I say "LOOSE" because i will remove them later on when i have the motor out of the frame (it prevents anything from unexpectedly falling out of place). unfortunately i dont have air, thus i dont have an impact wrench, but either the flywheel or crank shaft gear bolt can be loosend by putting a wrench on each one, and loosening one side while the other side is held. (it may happen that the fastener being held comes loose instead of the one your loosening, this is fine) however, once one of em breaks free then your gonna have to hold the shafts some other way, i used an old trick that worked in my 2stroke days. i put a piece of HARD wood inbetween the sprocket and swingarm, put the bike in gear and turn it over till it gets tight
then i put a wrench onto the fastener i wish to "break free" applying a fair bit of pressure onto the wrench but not forcing it furthur than necessary, I then tap the end of the wrench with a fairly big hammer (you need inertia) kinda like a cave mans impact wrench!
im not sure if this is a good method or not, but cant figure a better way when you dont have a clutch holding tool etc... ive used this method many times before and its always worked (of course you need to be patient and concentrate)
all smiles so far. After loosening the crank shaft bolt, flywheel nut, counter balancer nut and drive sprocket bolt, i start to disassemble the clutch by removing the five clutch spring reatainer bolts, remove the clutch stack as a whole (its faster and more "hassle free" to remove the whole stack at once) carefule you dont lose the pressure plate thrust bearing on the end of the push rod. the pushrod and thrust bearing assy can now also be removed.
the nut holding the clutch basket can be removed using the same method as stated above, Just be carefull not to strip the bolt as the previous owner did on my bike!!! (i needed a hand getting this loose, because a socket tends to buckle when you use only one hand. i needed a buddy to hammer on the end of the ratchet handle while i kept pressure on the nut and held the socket square to the clutch basket nut. otherwise i would have stripped the nut bare!!!) also NEVER re-use the locking washer just behind the nut (again to my dismay the previouse owner opted to reuse the washer which, thank god! didnt fail on me and trash my tranny!)
once this is off you can disassemble the clutch assy. i left mine on for the time being.
a tool which you MUST have when doing anything in the bottom end is a flywheel puller. its allways been important to have this tool in the past to prevent damage to the flywheel and crank, but its much more necessary on the CRF due to the integrated oil passage, seen on the end of the flywheel side crankshaft.
the flywheel puller hase a seperate part which screws over the oil jet so that the puller pushes on this "cap" and not the oil passage. mine required quite a bit of force to break free. once the flywheel is removed, begin to disassemble the head... refer to valve adjustment in the "HOW TO" section of these forums to get the cameshaft off. once your camshaft is off you can remove the cam chain from the engine.
at this point you may be wondering why we havent removed the motor... TRUST ME! getting the previousely mentioned fasteners off while the engine is on a bench is a chore even with the proper tools. keeping the engine in the frame assists in disassembly. with that said we can begin to remove the head. assuming that the airbox and subframe have been removed as previously mentioned, you can pull the carb "with boot" off of the head, then we can remove all cooling hoses from the motor.
note: its not necessary to remove the radiators from the frame, but the U-shaped hose located at the bottom and connecting both radiators can get in the way of the exhaust bolt on the head.
The engine stay mounted on the head can be removed and the 8mm bolts located on the cam chain side of the head and cylinder can also be removed. after these are removed you can loosen the four main Head nuts in a criss-cross patern.
note: the reason i remove the 8mm bolts first is to prevent any extra pressure to act on them if the 4 main head bolts are released.
remove the head using a rubber mallet, and then the cylinder. i tried removing them both at the same time, in short... it doesnt work!
once the head and cylinder are off you can remove the drive sprocket (that we previously loosened) from the motor and then the whole motor itself from the frame. it would be a good idea to clean the motor AGAIN! please excuse my lazyness in not completely cleaning the motor.
now like i said before, ive loosened the hard fasteners, they should come out nice and easy and you can lay each part out in the reverse order that they are assembled
http://www.flickr.com/photos/37543534@N06/3453700843/
i find that this way you have less of a chance of loosing track of parts. take off the clutch assy, crank drive gear(s) counterbalancer gear(s), kick starter spindle, kickstarter intermediate gear, and gear shifter shaft from the right side of motor. the counterbalancer is removed from the left side of the motor (take care when removing the balancer that you dont loose the plastic gear underneath it which is not held in place by any fasteners.
once the motor is clean (once again i appologize for my sloppyness!) you can begin loosenging in a criss cross "ish" patern the 8mm engine bolts on the left side (there are no fasteners on the right side which hold the engine together. also remember to remove the tranny drain plug as well if you havent allready done so, as this also fastens both cases together.
ive got to give a big shout out to user 124 who has provided dimensions for a rather usefull "bench" for supporting the motor. the dimensions are (inside width=140mm and inside length=324mm) made of 2x4. this helps alot when splitting the cases and working on the sides of the motor.
placing the motor "right side DOWN" into the bench alows you to grasp the left side case. get a buddy to use a rubber malet to tap on the ends of the crankshaft and drive shaft while holding the motor suspended a bit over the bench so that your driving the right side case AWAY from the left side. DONT HIT HARD! the left side crank is on a cylindrical roller type bearing which slides easily. Rather tap evenly and alternate from crank to drive shaft depending on seperation gap.
NOTE (IMPORTANT): if you are reusing the crank use the flywheel puller cap over the crankshaft end when hammering to prevent damage to the oil passage integrated into the crank.
The crank in my case came out of the right side bearing with little effort. if the crank is difficult to remove from the bearing, you can dissassembly the components on the right side case OR try overhanging the bench on a table. clamp the other end down so you dontdrop the motor on the floor. from underneath the bench use a rubber or brass mallet and drive the crank upwards. if it still wont go, use heat on the cases and bearing.
Ok thats enough from me right now. its exactly 4:00 in the morning, ive been writting this all night so please excuse any errors. ill try and revise it in the future, part two has not been done yet. i have to install the new crank and then reassemble. i will then try and get it up ASAP