Here are a few photos of the ZXR250C that I picked up for a project bike. I plan to completely restore every single piece on it. As you can see the bike was in poor condition, rusted and unloved. The first task was to inventory what I had and what I needed. I bought the bike as a rolling chassis and numerous boxes of unknown parts. Second task was to strip and disassemble every item and clean and refurbish it. (Except the motor at this stage) Third task was to reassemble the rolling chassis and fairings, assess any damage and repair. I was able to colour match most of the standard ZXR colours from Super Cheap. What I picked up After some TLC
Looking the part already Ive no idea of your mechanical skills but those subframe bolts should be torqued to spec and the fork tubes are sticking out the top of the triple tree like dogs balls ...??
just cleaning and checking the parts at the moment, bike will probably get pulled apart many times before the final assembly, then every part will be to torqued, loctited and or wire tied as needed. i will probably spend a lot of time on the motor, even considering mounting a 2 stroke during the original motor build. i have a few trades under my belt so nothing is to much of a problem.
opened up the bottom end for a look to find internals in perfect condition, haven't worked out the story with this bike yet but looking at possibly head gasket failure in a new motor. Covers have never been removed from cases going by the OEM gaskets and loctite application. here are a couple of picture of drive gears and shift fork drum, judge for yourself!
Motor external cleaned (4 days with a wire toothbrush and solvent), just need to final flush/clean internals and start to reassemble motor. Will probably spend a lot of time on the head, want to tidy up ports and detail valve components. plan is to set up motor and cooling system in bench frame and do running tests before install. attached a picture of lower end in cases, just using rubber gaskets to keep internals clean during task, you could eat you dinner of them!
Nice work. I guess you checked all the engagement dogs for wear whilst in there ? also the shift fork faces. Personally I would've pulled the head and looked for damage before cleaning as it might be a scrapper and I'm lazy
The top end and barrels/pistons are off the cases, they all need work as a note in a parts box said compression was mixed between cylinders, will hone or bore to suit new rings, possibly pistons. As far as gear clusters etc all good to go, I have some ideas that I may try on the top end to cool induction and possibly lift rpm limit by 2 or 3 percent, compression may be lifted as well, it's things that are down the track at this stage, bench running will start to give me the direction in which to go. One thing I do want to address is cam chain noise in zxr's, I want it quiet as a mouse. I am a little different to others, I always think outside the box.
like @zixxer said.. if you want a quiet ZXR buy a honda engine lol... I am just more partial gear driven cam noise my self... But it comes down to personal preference...
Also @Chuck i ended up getting very ill and not goin on my bike trip so I will have a look at dropping the engine out of the track bike... depends if i can haul my arse out of bed..
spent a few hour cleaning up the barrels and head castings, will need to buy or borrow digital gauges to check tolerances as per manual but all seams serviceable. The cam / rocket box is another story, as I have read in other members posts, cam chain wear on the upper surface is a problem. Not being a zxr250 expert it seams that any loose or incorrect cam chain tension allows the chain to contact the cover, creating wear, noise and alloy particles in the oil system. I would like to modify the cover via a tig welded piece attached to the external side and open up the inside area to add extra clearance for any chain movement, please comment on this issue as all information and opinions will be appreciated. also if some one could measure the 'clearance between the top of the rocker cover (at the cam chain position) and the closest object above it', so I can work out how much i came open up this area in the cover.
the chain slapping on the rocker cover will be in severe cases, you will SURELY hear something is wrong before it gets to that stage.
Keep the chain correctly tensioned and it wont be a problem. Modifying the cover to compensate for sloppy maintence seems to be the wrong way to look after an engine to me.
as posted before mate you shouldnt need too... also welding cast is a bitch and i could only imagine that welding cast ally would be a terrible. with the sheer amount of heat needed to weld ally it would warp things and they wouldnt line up again.. but hey thats just my opinion
