Hi all, first post just to introduce myself and my new toy/money-pit/nemesis/pal (will delete as appropriate when I know lol).
I'm new to Beemers (at least 2 wheel variety) but had & loved 80's shafties for years (Honda maggots, Yam XJ's and the like). Been out of the saddle for about 10 years now but found what seemed to be a good deal on Ebay so took a punt and won what was described as a 1986 K75S in pieces, which had been turned into a cafe racer & latterly a scrambler before PO bought and dismantled with the intention of restoring.
On collection I'd describe it more as a rat/survival style, lots of flat black/rough sanded tank, hacked wiring and enduro tyres. Still, not terrible for £310 if the engine was good I could at least get my money back in parts. Anyway, first order of business was to loosely assemble it far enough to see if I had the basis of a decent running bike. Before the post gets too wordy, it's decent enough & deserving of some love to make it into a reliable (if still ratty) summer toy. Main issues currently are the L-Jet & the hackery perpetrated to make it run/idle somewhat with leaking intake boots.
Basically instead of popping the plenum and TB's off & cleaning/resealing the intake boots, someone in the past has well & truly mallealated the throttle bodies. Initial settings are thus-:
Idle speed screw - completely missing, along with the stop plate
TB "Don't touch" screws - 1/2 nearly all the way in & 2/3 barely poking through, locknuts loose on both
Bypass screws- virtually falling out, barely hanging on the o-rings
TPS- all the way anticlockwise, acting as "idle stop"
Airbox - MIA, replete with AFM just shoved into the plenum's mouth with a bit of old boost pipe as a spacer, plastic cover loosely siliconed on so presume been tweaked internally, CO screw 12 (twelve) turns from seated.
I don't know what's more impressive, that the bike started at all (and ran as reasonably as it did) this way, or that somebody thought all that tweaking was necessary/advisable/easier than actually sorting the intake leaks.
Where it is now, with the intakes sealed up it starts well cold without "choke" and idles richer than Elon, gradually dying out as it warms. Crack the throttle and it goes lean to the point of cutting out. So now I've actually managed to confirm it runs/rides and is worth my time, it's time to get on stripping it and un-fudging the mess.
My intention is to find/make a new idle screw & stop, strip and clean TBs and verify TPS function then sync the TBs as close as possible using light oil & timing how long it takes a set quantity to drain through each throttle body & then once they're close enough throw the thing back together and hopefully get a more realistic reading on the vacuum gauges next time of asking (it had so little vacuum on first look, I honestly thought the intake valves were leaking or the HES was turned miles out of time).
OK huge ramble over, TL;DR Hello I'm new here and have a complete basket case of a K75S lol
Dan
