Afternoon all, Completed 2 year belt change the other day. Gates to Exactfit. Somehow something has gone wrong, and I'm hoping you can help. Everything seemed to go fairly smoothly until restart. Had used engine turning tool to make sure nothing was hitting for several revolutions after new belts installed... Fuel pump primed and stopped, starter turned engine over... she wouldn't fire. At all. Retraced my steps and realised I didn't rotate engine 270° forward after tensioning horizontal belt. Took covers off just now, plugs out, rotated crank pulley to case mark, fine-tuned with timing mark on flywheel window.. and I'm out by a bunch of teeth. The sight immediately made me very concerned. See photos below. Not only that, but I could hear a clear ting like a bell ring coming from the H head every couple of turns. Deep down, I know a valve touching a piston is the logical explanation for the sound... but I think I'll stay in denial for now. Assuming I've escaped damage somehow... couId I resolve by removing belts, turning cams to correct marks and reinstalling belts? Crank marks (ignore red paint): Horizontal marks: Vertical marks:
I’d take the belts off and re-do them. When the crank Mark is lined up both the cams, H & V, should be lined up with their respective marks as well. I assume the red dots were put on the belt by you ? When I do mine I turn the engine so the crank and all cam marks align then mark the old belt to correspond with those marks then count the teeth between marks (3x) then Mark the new belts in the same place, then lay the new belts on top of the old belts and make sure my marks line up then install the new belts so the marks on the belts line up with the marks on the cogs eith the marks on the casings. That way I know I have exactly the correct number of teeth between cogs. It’s too easy otherwise IMO to get just one belt tooth out, which you won’t notice when they’re loose but then which just buggers things up when you tension them. all bring well, as it didn’t start, no permanent damage has been done
Thanks mate. Yeah red paint was me and I use pretty much the exact same method to prevent issues exactly like this(!)
Unfortunately it doesn't need to start to bend the valves. Just turning it over is enough and the metallic noise you heard suggests some degree of piston contact took place. Refit the belts and double check the timing marks before turning it over, even by hand. You might just have got away with it but I'd recommend a compression test to be sure.
It looks like the timing marks are correct in pictures 1 and 3 , but out by one or two teeth in the other pics . @West Cork Paul wrote a really good method above ^^ It's been a while since I did mine , but from memory , with all the marks correct there should always be at least one pulley that needs to be turned against some spring pressure to get it in the right position @Derek .... or am I just imagining that ?
No, you're not imagining it. At the timing position the vertical cylinder inlet valve is fully open and the camshaft wants to turn due to the pressure from the closing springs. It needs to be held in position while belt is fitted. You can buy a tool to lock the cam wheels together to assist fitting.
I've seen a variety of them .... one looks like those pine tree air-fresheners for cars It slides between the cam pulleys , and the "branches " engage with the pulley teeth Or you can knock one up ..... in yer shed .... ... although I've only ever needed this one for dealing with the "silly nuts" . https://www.ducatiforum.co.uk/attachments/cam-pulley-tools-jpg.238520/
I've never used these cam lock tools myself. Too mean to buy one when I can hold the pulley in place with a pair of long nosed pliers with the points in the heads of the hex socket screws, or the holes in the pulleys of the older engines.
Good diagrams there ... If everything else is lined up correctly , the pulley labeled as " A1 " is the one that will always want to spring out of position . With the belt loosely fitted on the other pulleys , that's the one to do last . And for those of us with only two hands available ..... @RickyX posted a really good tip in the home-made tools thread , and the cost of the materials is zero .... https://www.ducatiforum.co.uk/attachments/25513c5b-835a-4153-8e2f-37a93517d3cf-jpeg.232968/
This isn't the first time I've changed belts. Just the first time this has happened. Probably didn't even need to get it done as the Gates belts looked perfect upon removing covers... oh well, better safe than sorry. Bike now starts briefly before dying... pump pressure issue being investigated.
