Forum

[Ivor]

Just checking my valve springs and I have a discrepancy compared to what Pete Snidel has in his manual. My spring lengths are, Inlet- Inner 49mm, Outer 53.5mm. Exhaust- Inner 48.9mm, Outer 53.7mm. Are they within tolerance of should I replace?

[papasmurf]

What model of Enfield would help.

[Ivor]

Sorry. It`s a 2003 500 Bullet Classic E/S

[Norm]

Just remember they were made in India and no 2 are the same length to begin with

[ChrisD]

Ivor, I’ve just replaced a set of Mr H’s competition valve springs on my 1996 535cc Classic.
New springs (both measured) inner=50.4mm, outer=54.2mm.
Old springs (done ~5000km) Inner=47.1mm(Ex), 48.1mm(In). Outer=51.9mm(Ex), 52.7mm(In).

I see a ~2-3mm shrinkage between new and used - is that expected? I suspect this isn’t caused by excessive heat because the head doesn’t get too hot anymore (since I kept burning exhaust valves at ~90km/hr). I’ve done the following to resolve that: alloy barrel, metal-to-metal head joint, larger oil pumps, open and finned exhaust, twin-plugged for faster burn, smoothed ports to remove hotspots and get better flow.
But, as Norm says, no two of anything Indian are alike!
Cheers, ChrisD