1985 K100 8V bogs when you wrench the throttle

Hi guys,

Have a problem with my 1985 K100 8v.

When you rack the throttle hard, the engine will bog or stutter - and even more so under load. Yet if you gradually open her up, she pulls very strongly.

Shes had new plugs, leads, fuel pump, filter, hoses, regulator, air filter, and i've had the injectors cleaned and tested.

The fuel pressure is spot on according to my gauge.

Any ideas? I rebuilt this bike from boxes of bits, so know the bike quite well - but cant guess why this is likely to be happening.

ToGGoT

Ahh, "air flow meter"

Yeah, i had wondered about that. Might see if i can get another one.

How does the pressure balance work?

ToGGoT

Before you start swapping such expensive parts as an air flow meter, it is worthwhile to first make sure your throttle bodies are correctly balanced, and with that accomplished pay a car shop ten or twenty bucks to have them sniff the exhaust with a four gas analyzer. That will tell you a great deal about what is happening in your engine and save you a bunch of grief making uneducated guesses about what is wrong.
When an engine bogs under load like that I tend to start looking for vacuum leaks, especially around the throttle body seals. You can check for these by spraying non-flammable brake cleaner on the intake parts individually and see if the idle speed or quality changes when each part is sprayed. That will usually expose any vacuum leaks.
Oh yeah, don't bother with anything until you confirm your valves are all adjusted properly. That is basic.

Zitat von "Themason"

Oh yeah, don't bother with anything until you confirm your valves are all adjusted properly. That is basic.

+1 on checking the valve clearance 1st, especially before a TB sync.