changed the timing belts today on my 916, in the work shop manual it talks about a belt gauge. I havent got one , I have just tensioned them like any other belt, will that be surfice or should i try and get a tensioner gauge?
There's plenty of info on this on t'internet. I have reliably used the "wiggle" and "Allen key" methods on my 916.
They'll more than likely be just fine but frequency measurement is the thing now. 110hz for new belts. If you have an Android phone gStrings works just fine. There will be another app that works for iPhones.
I just used the 1/4 turn tension check on the long belt run when I did my 916. Same method I use on car engines, I've never had a belt or bearing failure in 30 years on any one I've ever done.
You'll have done many more than I have, but for what it's worth, when I used the allen key method on my 900 (based on the helpful advice on the web) it just felt more accurate to me than the old "twist" method which I have used on cars.
Nah, finger and thumb twist between the cam pullies works for me. About 30 degrees twist. But timing belts is one issue where there are lots of opinions.