Hi Guys.
Bike ‘89 FK model.
I have a rough running bike at present, and am going through the usual ball ache tests etc.
So with the vacuum hoses , two from the pet **** to each pair of carbs, questions : Presumably these need sealing when using a remote fuel tank yes?
Also: no doubt I’m going to have the carbs out if all else fails, and am without a manual, and reading other threads the pilot needs outing 2.5 turns, I’m fine on that. Has anyone got a carb diagram so I can decipher which jets have which name.
Thanks guys.

 

Oddly enough I m actually thinking the electric side of things is not as it should be.
Having been out for a ride last weekend, clearly on only 3 cylinders, I put the bike away and didn’t start it again until I’d removed all plugs.
Cylinder number 3 was sooted up, not coked but definitely not the nice grey tan of the other 3.
During my endeavour to find the cause, I then warmed her up and took a compression test….all cylinders around the 150/160 mark.
Battery was new in April, however, I don’t trust batteries , they have a habit of throwing a plate, or doing something silly, an easy check for tomorrow.
I am going to do the stick coil conversion as the previous models I had certainly had a smoother running engine.
let’s see the outcome…….

 

Good luck with the investigation.

All the shop manuals seem to have disappeared from this site and my Haynes manual went with the bike when I sold it.

I'd do the stick coil conversion and see what it's like after that.

 

Just found this old post from you.

https://cbrforum.com/forum/workshop-...al-pdf-155697/

 

Might have stuck float-valve not sealing on #3.
Fuel-level would be too high.

 

Stick coils arrived today 😀


Re coils await their new home…update on the result.

 

Removal of the original electrical plug has two wires joined, a bit weird.



Any way think I found why the weak spark : On removal of the little C shaped metallic clips which hold the original coils in place looked fairly’ non conductive’, for want of a better description.

Following Sebastianbears excellent ‘sticky’ on how to ……, I’m puzzled how the stick coils get their earthing, as he says you don’t need the fifth wire.
I did this conversion myself on the two bikes I had previously, some years back, but this age thing gets the better of me.
Anyway, I’m a third way through the task, ran out of time, but managed to extend the wires, with a filament of copper wire to join, then solder , then heat shrink to finish…….more another time

 

Going well mate, keep us posted.

 

Good job on that repair! Proper western-union/linesman joint!

Blk/wht wires split because they are power-wires to each factory coil. It's ignitor that earths other side to fire coils (blu & yel wires). If those sticks are used, you should test them before using:

1. insert plug into coil
2. connect + terminal to blk/wht wire terminal
3. repeatedly tap wire from other terminal to -negative battery terminal.

Does it spark?

Will want to wire stick-coils in 2 series circuits to simulate impedance of twin stock coils. Won't overheat and fry ignitor that way. Wire them up like this:

 

Thanks for the info Danno…..A western union joint, never heard that one before. But thank you.

ok so the wires jointed to terminals as required



And a 4 way waterproof connector, male / female set up.

I took off the old wide diameter grommets off the original plug cap / leads, and used a large diameter hole punch to knock out a central hole , some 4 mm smaller than the coil stick



This makes a lovely neat job of it . I did remove the rubber sleeve of the coil stick and discard, but put the rubber boot back on at the foot of the stick. Silicone grease helps things off land on.

Just had to try to start the bike before shield wrap etc.
😀 That’s a real bonus, she started up immediately, ran somewhat smoother than before…happy chappy.
just got to affix the new loom to the original coil chassis, and wrap some self amalgamating tape around the wire/ sleeve joints to stiffen up.
So there it is .