Don't see how they could be wrong? Unless a different number of teeth, in which case they'd be way too long but a 'wrong belt' just wouldn't fit. Having removed the base gasket will make a difference - I had 1mm skimmed off my 916 heads and also removed 0.2mm from the base and I needed larger pulleys to get back the tension and then needed to 'degree' the cams to get the timing back, but your base gaskets were probably only 0.4mm or so? That said, maybe it's enough to make them close to full adjustment when new so that they can't quite get it when used and (slightly) looser? I wouldn't have thought so though...
Can someone post a pic of 900 tensioner arrangement? I'm not convinced I have the correct ones. Belts definitely slack on full adjustment. I do not believe this is due to lack of base gaskets alone.
Mine look like they don't have enough 'throw' look how close the bearings are to the pivot point. There's never gonna be much adjustment and Google reveals different looking adjusters with a longer throw. If that makes sense.
I may have the answer. My cases are actually ST2 cases. They are the most part the same as the 900SS. There's subtle differences and I am wondering if this is why I now have this issue. I reckon if I can change to these longer arm tensioner it would fix my problem.
Make sure the roller / bearing diameter is the right one - timing will be out if not, I reckon........or will it?
Your fixed bearing looks to have a larger gap between it and the casing, if it had a larger bearing it would tighten that side of the belt resulting in pulling the cam slightly backwards. Steve
ST2 cases are basically the same, they use the same tensioners. I had an ST2 engine along with the 900 (as a cam donor) and saw that most parts other than heads & cylinders were the same. The belt tensioners and covers were the same. This is what mine looks like; The tensioners are near the end of the slots but still some adjustment left.
Yeah, gotcha, but that's fixed and not the one I am changing. As the other side is adjustable, it will not matter what size the bearing Is, or indeed where the pressure is applied surely?
The cases are slightly different too. Not by much. Had to change a few things. The oil pressure release valve is in the oil pump not the case, no hole for the coil pickups and the case gaskets different to list a couple issues. I have ordered some longer arm adjusters, will report back when they arrive.
Stating the bleeding obvious, on pushbike gears, the sprockets that alter the gearing aren't the fixed ones, but the ones with different diameters - they are sort of shortening or lengthening the chain in a way.
You've Lost me Al....Im not changing the fixed idler. To me this needs to be a set size in order for the cam timing to be correct. If the idler was bigger then yes, I agree that the cam would be pulled back. However I am working at the other side of the belt, where it's adjustable. This will not affect the timing. Am I making sense, it's tricky to explain
Makes sense to me. The other side of the belt is in tension and the fixed pulley, cam pulley and driving pulley all remain the same, so any change to the movable tensioner will have no effect on the timing.
