Introduction: HONDA CB250RSA-T
I'm no mechanic - but I have been abusing this little thumper for some thirty years and we have traveledwell in excess of 100,000 miles together. This RS has been written off twice, has suffered smashes and scrapes, seizures and hemorrhages, theft and fire and is the recipient of several donor parts - some new, some used, some from 'none RS' bikes and two and a half engines - a Trigger's broom of a bike :-)
A difference of opinion with the DVLA and a sh*t-load of other more important stuff to do had diverted my attentions away from this crackin' and much loved little bike - I've been itching to shake it to the top of the list, so, rather than watch it rot any further, to the top of the list it went. I'd really let it go this time and I also had my doubts about the previous engine rebuild - something wasn't right. This will be it's third major overhaul.
Anyone familiar with the RS will understand the attraction and why it's rapidly becoming a sought after modern classic. You'll also notice the none-standard headlamp and lower legs :-)
Step 1: Strip Down.
Bags. Labels. Get on with it!
Frame - painted (hammered).
Stands - painted (hammered).
Step 2: Cylinder Head and Barrel.
No real problems with the bottom end so no need to lift the whole engine out. The cylinder head and barrel are easily removed. The cam chain had had very little running time and there was plenty of tolerance in the auto tensioner (I wish I could same the same about the tensioner guides).
The barrel needed to be de-glazed, at the very least, so that went off to a specialist engineers. Surprisingly, a de-glaze was all that was required and so I ordered a standard size piston, pin and rings kit (a good one).
The cylinder head: - The valve springs were still at spec length - the stems appeared straight - the guides were nice and tight. The valve seats, however, were a bit grotty, so, a quick and simple wiz with grinding paste and a new set of (X4) valve guide seals and the head was sorted. I adapted an old drill-stand to create a pretty good valve-spring compressor. So far so good.
Step 3: Crank Case Covers - Off.
As I mentioned, there were no real problems with the cog box or selectors but I did need to get to the counter balance weight adjuster, the generator stator and rotor, a splattered neutral switch, kick start and output shaft oil seals and the clutch and oil filter.
This was absolutely the very last available notch of adjustment on the counterbalance. but it should be good for another 30K miles.
The ignition system had started to play-up and it was looking like the stator and/or the ignition coil. I sourced a good, used stator and a new coil (I had them both professionally tested - without a conclusive, satisfying result - this was a worry and lead to problems later in the rebuild) A faulty CDI would more likely result in complete ignition failure but I already had a spare one (just in case) and I grabbed an AM regulator/rectifier as a poor charge was also becoming evident.
The clutch was fine-ish, so I shuffled the friction plates and bought a new cable.
Oil seals at the ready.
Step 4: Re-install Engine
I popped the rebuilt barrel and cylinder head back on, set the timing and it ran - ish. A bit rough - but it did run.
Okay - I knew the carb was grotty, for which, a full repair kit was on the way, and I'd swapped the stator, but there was still plenty to do and I assumed the running would improve as other new parts were added later in the rebuild.
I moved-on to other aspects of the project.
How wrong I was.
Step 5: Carberetor.
The carb was in a terrible state and needed a complete overhaul.
Came up lovely.
Step 6: Brakes, Bearings and Tyres, Etc.
Master cylinder - replaced with good look-a-likey.
Rear hub - cleaned.
Front (N) caliper - rebuilt.
Good quality shoes and pads - fitted.
Front wheel bearings - replaced.
Wheels - cleaned.
Standard tyres - fitted.
Steering head bearings - checked and greased.
Swinging arm - checked and greased.
Cables - clutch, choke, throttle (X2), tacho, decompressor and speedo - replaced.
Front forks - new seals and fork oil.
Step 7: Tank
Tank - painted (gloss).
Mud guards, tail piece and side panels - painted (satin).
Headlamp - painted (gloss).
Step 8: Seat.
Seat - recovered.
Step 9: Clocks and Other Bits 'n' Bobs.
Clocks - stripped and cleaned. Broken tacho pointer - glued.
Handlebar switch-gear - fixed grotty connections.
Rear brake light switch - fixed and adjusted.
Headlamp bulb - replaced.
Horn - cleaned, painted and tuned.
Clutch lever - replaced.
A three month period of motorcycle emptiness was endured whilst the problem of not starting was solved.
(Thanks to biker mates)
Step 11: Up and Running.
Hardly a showroom piece but it sailed through the MOT and runs like a dream (but ten times better ;-) ). Still, as always, a few jobs to do, including fitting new rear shocks and more painting to the tank.
I enjoyed that.