Rough running low down and high idle when warm

[Dukedesmo]

Originally Posted by FrankenDesmo

However, I've just done the valve clearance checks...

Vertical Inlet Open: 0.04mm (0.05 required a tiny amount of force)
Vertical Inlet Close: 0.14mm
Vertical Exhaust Open: 0.04mm
Vertical Exhaust Close: 0.09mm
Horizontal Inlet Open: <0.04mm (didn't have a feeler gauge smaller, 0.04 required a tiny amount of force)
Horizontal Inlet Close: <0.09mm
Horizontal Exhaust Open: <0.04mm (same as Inlet)
Horizontal Exhaust Close: <0.09mm

Unfortunately your readings are essentially 'inverted' as in you want the closers tighter and the openers looser, but that's what happens as they wear - the openers close up and the closers open up due to wear and you basically need to move the clearances by adding whatever you remove from one to the other.

I aim for 0.1 - 0.12 openers and for the closers to be as tight as possible without binding but definitely under 0.1, 0.05 is good IMO.

My advice is fit MBP retainers rather than the half-rings as much of the wear/variation comes from the rings, just re-fitting them upside-down can change the readings significantly.

I was checking the clearances on my 916 this week and I only needed to change one opener shim on all 8 valves (I didn't really 'need' to change it either as it was only at 0.14mm!) and that is the first one I've changed in probably 5 years. This is a huge benefit on a 916 as the exhaust clearances are tricky to check due to access, especially the rear cylinder as the rear suspension/subframe is in the way, plus there are twice as many valves/shims as a 2v and changing them is trickier.

I reset the Monster clearances last year as I had the heads off and they were unchanged this time round.

General rule of feel is that you can't 'feel' a clearance of 0.05 or less by hand so you can get get an idea even without gauges.

BTW, I don't know where Haynes get their clearances from? - at least for the 4v...