XS850 Service Bulletin Thread

[XS850GUY]

XS
XS850 Circuit / wiring diagram

[XS850GUY]

xs850 neutral relay safety circuit

[XS850GUY]

XS850 Ignition Circuit Relay Mod

[XS850GUY]

XS850 Ignition Circuit Relay Mod:
Before:



After:

[XS850GUY]

XS850 / 750 Valve Shim Chart

[XS850GUY]

XS850 Flasher/Canceling Relay Mod

[XS850GUY]

[Radioguylogs]

Thanks for the info.

Those service bulletins don't seem to be issued by Yamaha, considering the dates are within the past month?

[XS850GUY]

Thanks for the info.

Those service bulletins don't seem to be issued by Yamaha, considering the dates are within the past month?

Hah! Certainly not!

I created them because info regarding these topics is sparse & I'm giving back as I make discoveries and progress. They are as much for my own benefit as the community at large.

[XS850GUY]

Further detail on the Flasher Relay and Flasher Cancel unit. Although partnumbers may vary, these basic concepts should apply to most any yamaha street bike of this vintage that includes the flasher cancel unit. Enjoy!

[gtem]

I'll have to point my brother to this thread (his main bike for the last 4 years has been a '79 XS750F)

[XS850GUY]

Success! Here's the xs850 gearwheel stack out of the bike. No split cases, no exhaust pull.. So far pretty easy, besides research and mental prep.



With the transmission drive axle end bearing cap off, the 2nd gear wheel can come out w a snap ring pliers. However the 5th gear wheel is held captive by the #3 shift fork. To release the 5th gear wheel, you need to pull the clutch basket & oil pan. Then from below remove the e-clip from the #2,3 shift guide fork then slide out to release the #2,3 shift forks. Then the 5th wheel can slide out the end bearing cap opening.

Next, to remove the entire gearwheel stack the drive axle carrier bearing cap needs to be pulled.

There are 2 things stopping the bearing cap from popping right out;
A: #2,3 fork guide shaft needs to be fully retracted to clear the bearing cap,
B: Oil pump also needs to come out. 3 cap screws hold the pump to the lower case. Two of them are obvious and accessible as soon as the oil pan is off. The 3rd is hidden behind the pickup spout.. so. 3 JIS screws to remove the screen, then 2 small cap screws to remove the spout, then you can get at the 3rd fastener.

The gear dogs on the remaining gears also showing similar wear to the 2nd/5th gears that I already pulled.. Likewise, the #3 gear fork is very worn.

I'm this deep already, and since everything is apart, I went ahead & ordered a complete set of NOS gearwheels & the #3 fork which was pretty worn also) Total spend for the 1-5 gearwheels+#3fork, $460.05
Total spend on the bike so far, including everything, purchase price ($200), registration, repair/replace parts, fully rebuilt brakes/MCs w new pistons & all new spiegler lines + a bunch of NOS/Rare spare parts that I'll keep in stock, $3,486.69

Doing pretty good so far and once buttoned up I'll have a basically brand new gearbox.