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350TSS · 22-01-2020, 04:13 PM

A frustrating day today, the horizontal cam belt got put on and tensioned using an estimated position for the timing.
The camshaft pulley nuts got loctited and torqued up, I had a bit of a concern as to how to hold them whilst applying 60Nm to the jackshaft nut and 72Nm to the cam nuts. Without the flywheel on (which I still have not located) the only way, I had to hold the engine was via the nut on the jackshaft at the other end which obviously meant all the torque was being transmitted by the belts themselves.
I then tried my piston locker that I made yesterday but it didn't work for two reasons, first I do not think it was quite long enough and second because at 7mm thick, I think it got in the way of the valves. Even gently turning the engine over with it inserted I felt a slight resistance which quickly freed off. I obviously inserted it on the wrong stroke and I think the inlet valve nicked it.

private image upload

So I set TDC with the dial gauge through the plug recording where on the timing disc the gauge began to move as the piston rose, then reversing the engine and doing the same on the other stroke and then splitting the difference and setting the timing disc to TDC. Amazingly the jackshaft pulley and the timing mark on the crankcase were perfectly in line.
Now with a true TDC I started the process of determining at what point the inlet valves on each cylinder reached peak opening. I started with the vertical cylinder and measured 3 times and I got reasonably consistent results at 443, 444.5 and 447 degrees after TDC.
Moving to the horizontal cylinder the results were all over the place, the first measurement was at 453 and then I had two results at 384 degrees ATDC.
I think I know what was going wrong with the last two, the DTI is mounted about 20 degrees to the horizontal and the return spring on the probe is lazy (ancient hand me down DTI) and the probe simply was not following the valve lifter accurately. For the vertical cylinder, the DTI probe obviously had the advantage of gravity. By this time I was getting tired and cold and frustrated, I will re-measure tomorrow and hopefully find out the difference between the two camshafts in terms of advance and retard.
I still obviously have to determine what is the right time for the camshaft to be at peak lift and at present cannot find a spec sheet for an M900 with a V2 head.
I need inlet opens and inlet closes timings.
An American website lists this information as IO 43 and IC 85 and I spent quite a bit of the cold day in the garage trying to reconcile these numbers - to me they are meaningless?????

22-01-2020, 04:13 PM	#1109
350TSS Too much time on my hands member Join Date: Jan 2013 Location: Shipbourne Bike: M900 Posts: 1,419	A frustrating day today, the horizontal cam belt got put on and tensioned using an estimated position for the timing. The camshaft pulley nuts got loctited and torqued up, I had a bit of a concern as to how to hold them whilst applying 60Nm to the jackshaft nut and 72Nm to the cam nuts. Without the flywheel on (which I still have not located) the only way, I had to hold the engine was via the nut on the jackshaft at the other end which obviously meant all the torque was being transmitted by the belts themselves. I then tried my piston locker that I made yesterday but it didn't work for two reasons, first I do not think it was quite long enough and second because at 7mm thick, I think it got in the way of the valves. Even gently turning the engine over with it inserted I felt a slight resistance which quickly freed off. I obviously inserted it on the wrong stroke and I think the inlet valve nicked it. private image upload So I set TDC with the dial gauge through the plug recording where on the timing disc the gauge began to move as the piston rose, then reversing the engine and doing the same on the other stroke and then splitting the difference and setting the timing disc to TDC. Amazingly the jackshaft pulley and the timing mark on the crankcase were perfectly in line. Now with a true TDC I started the process of determining at what point the inlet valves on each cylinder reached peak opening. I started with the vertical cylinder and measured 3 times and I got reasonably consistent results at 443, 444.5 and 447 degrees after TDC. Moving to the horizontal cylinder the results were all over the place, the first measurement was at 453 and then I had two results at 384 degrees ATDC. I think I know what was going wrong with the last two, the DTI is mounted about 20 degrees to the horizontal and the return spring on the probe is lazy (ancient hand me down DTI) and the probe simply was not following the valve lifter accurately. For the vertical cylinder, the DTI probe obviously had the advantage of gravity. By this time I was getting tired and cold and frustrated, I will re-measure tomorrow and hopefully find out the difference between the two camshafts in terms of advance and retard. I still obviously have to determine what is the right time for the camshaft to be at peak lift and at present cannot find a spec sheet for an M900 with a V2 head. I need inlet opens and inlet closes timings. An American website lists this information as IO 43 and IC 85 and I spent quite a bit of the cold day in the garage trying to reconcile these numbers - to me they are meaningless????? Last edited by 350TSS; 22-01-2020 at 04:15 PM..