Compression ?

[chrisx1]

What compression should I be expecting on a Thunderbolt that's done about. 50 miles on new rebore, pistons and rings? I've got about 100-110

[chrisx1]

Note: compression checked with engine cold.

[V500]

Sounds low, and I doubt the rings have bedded in enough yet. Don't be too limp-wristed with the throttle.

[rhyatt]

When you were kicking it over , did you have the throttle wide open ?

[chrisx1]

No I didn't have the throttle open at all.

[chrisx1]

The top end is a bit clanky, I'm a little worried a valve maybe connecting with a piston. I've redone the tappets so it's not that.

[DAVE BRADY]

Hi,

The workshop manual tells you what compression reading to expect but a bit more running in will help.
Unless you have fitted very high compression pistons a valve will not touch the a piston.
Re-check the valve clearances at 8 thou inlet and 10 thou exhaust and make sure oil is getting to the rockers.

Dave.

[rhyatt]

Important to have throttle wide open , otherwise there is no air getting in to compression.
It'll make a difference for sure