non regular idle revs on 885i

[stefanjochems]

dear readers,
i have a tiger 885i from 1999 and there is something strange with the idle revs. when i start the bike the reves are high 3000rpm. after a minute it goes doen to 2000rmp.
after a minute or so the rev is 1200. When i drive an the engine is warm the revs are unstable. for a traffic light the revs can go up to 2500 or higher end the next trafic light the rev is 1200. The fuel consumption is ok 1 on 18/19.
what can i check to solve this issue. the strange part is that during one trip the rpm is unstable.
please some tips 🙂

Thanks

[Flyingwombat]

Hey man, probably see my other thread, it's long winded but.

1. Battery - ensure charged and healthy
2. Fuel trims with TuneECU - make a note of the map, trims, and IACV settings before fiddling
3. Check all cylinders are firing at idle by turning it on and checking exhaust outlets for warmth (thermal camera or burn your hands methods are acceptable) - issue here could be spark plugs
3. Throttle cable adjustment and free movement - should not stick, best to do with tank off
4. IACV function, throttle body balancing and vacuum leaks - Sort any issues (loose balancing screws is a thing) If you see any backfiring into the throttle body then consider timing issues and valve clearances
5. Engine map - check it is up to date
6. Fuel pump test (listen for abnormal squealing), fuel pressure, injector function - replace injector seals (lubricated with engine oil) if injectors are removed, clean them at the same time.

Guides for most of these things are on here, or you can find on youtube (Delboys Garage has a whole section on Tigers). I would also download the 885i user manual for the right VIN too

[stefanjochems]

thanks for the tip 🙂 will work on it

[Titus]

I never had and never will have a efi bike, but on an efi car engine, most idle issues relate to the idle air control valve, engine temp sensor and/or air intake temp sensor, last but not least vacuum leaks around the iacv and tb. Best of luck and keep us posted.
I would try unplugging sensors one by one to see if anything changes. If unplugged the temp sensor usually make the engine run faster and richer so dont worry, map goes to a 50/50 emergency mode.

[Lee337]

Start with the easy stuff & check the hoses from the iacv. They are a weak point & can split. Most owners replace them with 6mm internal diameter (i think) silicone hose.

In most cases this is the cause of a rough idle.