Nipping up

[garry inglis]

I notice you say after 118 miles it nipped were you opening it up more than used to it could be piston ring gap it needs one for when the temp goesup and expansion starts

[double h]

That's what I thought you might say. 19 is pretty much suitable for standard motors these days, especially with a clubman, but anything running an expansion, kit, or high comp head may well need 17 or less on today's fuels. I know a number of people having to run mild road tune motors at 17 to stop their bike from seizing and plenty of people (me included) running 16 or 15 static on tuned motors, with many advance retard ignitions suggesting a range of 19 starting and retarding to 14.

These days 19 is simply too advanced for many motors and will lead to nothing but trouble. I helped a mate setup his iron 175 (22 + clubman) and it would always run hot at anything more than 17. Like this he did a number of Euro Lambrettas and thousands of reliable rally miles. He then took it to a dealer to have the main seals done and they told him that they had 'corrected' the ignition timing to 19 dbtdc, which he didn't inform me of until we were stuck on the hard shoulder with no compression, following the motor seizing. We then had to get recovery to the ferry port, strip the motor down, replace the piston and rotate the stator to my marks that I'd put there for 17 degrees. The bike then did the Avignon Euro without issue, including over 400 miles in one day. Yeah, thanks for 'correcting' the ignition timing!

Adam

ok cheers for that.17 dbtdc it will be after the rebuild. Just hoping the dammage is minimal and can be fixed with emery paper.

[double h]

I notice you say after 118 miles it nipped were you opening it up more than used to it could be piston ring gap it needs one for when the temp goesup and expansion starts

No mate, the ring gap is more so no issues there.