A question for my 84 K100RT.

Since the start of the year have done lots.......but I have a not good running issue I need to resolve as its affected fuel consumption as well as the running. I took it for a camping weekend and there was an improvement since the most recent change, as in new injectors but still not right.

Service, plugs, air filter, coolant etc all good.

Things I have done as part of what I had planned.

Swapped coils with LT. No change.
Changed injectors. Very significant change, cleaner start, cleaner pick up but still have a diesel knock at cold and excess fuel consumption.
TPS is working and has connections cleaned. That made a big difference.

I can swap out both ICU and FICU with my spares, but am wondering should I be looking at anything else?

Cracked throttle body boots?

Have you tried swapping the spark plug leads?

Diesel Knock?

I read that the later 84 production bikes was when the design changed for unleaded fuel.

Is it possible your bike wants/needs lead substitute to run properly?
Just a stab in the dark.
My 81 R65 airhead needed the valve seats changed for unleaded fuel compatibility.
Don't know if same holds true with kbikes.

Tagaz

You are right about the leaded/unleaded fuel. I would go with that but I have put over 50k miles on it in the last 4 years without any unusual running/knocking/fuel related problems and when I got it first the fuel mileage was better than on the 92 LT at a comfortable 10 miles per litre and 11 miles per litre off motorway.

In terms of starting, pick up etc all is good and very clean. The diesel sound is only happening at cold too so nor really sure where its pointing.

We have a workshop on Saturday and going to take the opportunity to look at the rubbers etc and will swap plug leads again.

I have a trip to France in September and have my fuel stops worked out at about 100 mile intervals but would prefer to plan 3 stops 2 hours apart rather than 4 stops.

have u swapped out the FICU yet?
if engine is dieseling ie. running on after ignition is off, then where/how is the fuel getting into the cylinder?

or is it possible the knock is from the bottom end not the cylinder ie. pston slap?
compression test?

No running on ever. The knock is same sound you get on a diesel engine with injector issues, as opposed to the normal sound of a diesel. On diesel cars over 30 years so fairly used to the difference.

Swapped injectors as one was definitely leaking and a second was suspected of leaking. Brand new set gone in and that made a difference. No wet plugs and no staining on manifold after being parked up.

Sounds is definitely not piston slap, also no oil consumption or topping up needed.

All headers now run to same temperature when I fire up, before I changed the injectors there was a difference which also pointed to no 4 leaking. Injectors were all intact when they came out.

FICU probably get changed tonight, will see if that makes any difference. I will swap ICU at the weekend.