120 miles and hitting the powerband on a rebuilt old 2 stroke.

After last rebuild of my RD400 I treated it gently for a good 500 miles and had heads off during that period till I was confident all was OK

Biggest mistake we get in the RD club is people thrashing rebuilt engines from virtually day one. Slightest little air leak or carb not right can easily destroy the engine and you are back at square one.

Took my time settling my 400 down after last rebuild and it did me good for 20,000 miles