850 Lamda and start problems

Hi all,

I have a 1997 850R which is giving me a few new problems.
Firstly when I turn the key, the starter jams, at least that's what it feels and sounds like.
The engine does a quarter turn and then stops with a thudding hiss.
I retry and it starts.


Could this be an indicator that the starter motor brushes that touch the commutator are worn out?
The other problem is that my lamda light has just come on. Its maybe important to mention that I recently equipped the car with the 3" turboback exhaust mod. The car has no cats, but then again it hasn't had cats for 6 years,.
Is the sensor overheating?
On a friends recommendation I disconnected the battery to see if it resets itself, but no joy.
Power seems to be on the down side since the light came on.
Any help would be appreciated

Paul