fizzy

I am going to change fork oil this winter. Standard valves, straight would springs, you say use 5W instead of OEM spec 10W? Been using this brand engine oil in bike(s) for years, no issues. High Performance 5W 5wt Motorcycle Fork Oil Suspension Fluid 1 Litre 1L | eBay UK

Yes, possible. It is also possible that low voltage causing intermittent spark on the spark plugs. Do easy stuff first. Have battery tested at auto parts store. Test output from stator. You are correct that R/R is a common failure. Best option is an upgrade to a genuine mosfet unit. Not only BB's but many other bikes of similar vintage. Check out this site for more info and the genuine article for sale. Roadstercycle.com | SH847 & FH027EA Regulator Kits | Jack Fleming If it's in the budget, the FH027AA super kit best bet. FYI the SH847 is an upgrade above the 027 but a little pricey. I have used the FH020AA (previous model) on 2 machines, many years and miles, no issues at all.

Agree with Tomek, charging system is weak. As stated, check battery electrical connections, also large 3 pin connector between stator and R/R (regulator/rectifier) and starter relay/whole bike fuse as both can melt. If all good, test the stator output. Do test with a fully charged battery as bike will be running on battery power alone. I say stator as dicey stator will give low output (less than 13V) while dicey R/R will give extra high output (15V+), generally speaking. Both of which are bad. A bad battery can also give low readings, so have battery tested if in doubt. 1. Basic test: disconnect large 3 pin from above, run engine and test voltage output from 3 stator wires all 3 ways. Should be about 60VAC @ 5000rpm with all 3 readings being the same. 2. Load test, same as #1 but substitute 60W 120V incandescent bulb for voltmeter. It will burn bright at 5000rpm.

1. How many miles to the tank? Fill up to warning light on, normal riding. 2. After a cold start with high idle speed,, does the idle speed go down to 1100rpm once warmed up?

Before you start to replace parts willy nilly, I would recommend to nail down the running issue first. But yes, the parts you show above would be good preventative maintenance. FYI: in the event to remove the fuel rail, remove the tank, not just lift it. Best bet is to siphon all the fuel out first. Fairings can stay in place.

No need to pull fairings. Remove seat then 2 tank bolts and rotate tank up 6" and support somehow....best if tank is on E. Watch out for 2 tabs that attach to tank from infill panels Reach in and pull vac line off of the FPR with engine recently turned off. As stated, line must be dry.

Add a wheel bearing to the list as the grease will be all gone. There is a small bleed valve in the system that can clog and maybe cause symptoms you have. Do not damage it, AFAIK no longer available.

One more thing to check: if the FPR (fuel pressure regulator) has a pinhole leak, which is common, it will send excess raw fuel to 1 cylinder only, causing poor running which will clear up at high rpm/throttle opening. Check is.... after a run, pull vacuum hose off FPR (mushroom shaped device RHS fuel rail) and check for fuel in the hose. if ok It will be DRY DRY DRY.

I am going to guess that in the early days of this style BMW engine, it was fairly simple and straightforward. Not anymore.

Personally, I would actually install on the bike and test over 10 miles or so with voltmeter connected to battery (13Vish to 14.5V), also check for overheating. There are only 5 wires.

My takeaway from the above pics is...... wow that machine is clean.

RRRRRobar

Sorry, I got you mixed up with Zero. Whoops. 😨

So you plan to R/R the R/R? Say that 4 times quickly and you may be Hispanic.

It just plugs in, you may want to verify it has the exact same plugs as the one on there now incase it needs a workaround. Edit: I would reuse the rad fluid after running it thru a paint strainer.