BMW R1200RT/R1250RT Forum

I realise you more experienced mechanics will be giving a large "sigh", but if you dont ask you dont know!!


When fitting a new alternator belt and manually turning the engine, should the engine be in gear or in neutral?


I have googled some varying techniques to carryout this task and some people say to remove spark plugs to make turning easier on the compression stroke, one guy makes it look easy just turning the pulley nut with a spanner, Im sure I read somewhere to have the motorcycle in 6th gear....ultimately I am unsure!!!


your advice will be appreciated.


Chris... ^-^

I would remove the plugs and turn the engine with crank pulley nut with the bike in neutral

I'd remove the plugs and put the bike in 6th gear and get a helper to turn the rear wheel whilst you guide the belt on.

You can't beat a video, good access and the correct tools.

DIY, poor access, https://www.youtube.com/watch?v=vNO0fY9b0lA

With the bike in gear, the guy uses his feet to turn the rear wheel and therefore the engine.

The BMW way, https://www.youtube.com/watch?v=KzEIEJs70n0

Bike in neutral, seems to turn easily enough without removing the spark plugs, although obviously as mentioned above, it'll make turning the engine easier.

When I last did mine, it was way easier than I expected. I'd got the main plugs out anyway as I was fitting new iridium ones - big adjustable spanner on the nut (WO Eng Norman Maddox, 85 Sqn RAF would have been turning in his grave....) and the new belt went on a piece of cake. The only thing I'd say is to double check the belt fitment on the top pulley - its easy for one of the belt grooves to sit outside the flange of the top pulley, you can easily check it with your fingertips or get a bright light in there so you can see it clearly. My light was nowhere near bright enough, it looked fine even though it wasn't! Fortunately I spotted it before refitting the front cover.
Pete

Plus, make sure you get the correct belt, viewtopic.php?t=45.msg43957#msg43957

thanks lads....

Changed the alternator belt today no problem.


Left the spark plugs in and turned the crank pully nut...