Today I took my timing cover off to have a look inside. I haven't seen in there since last winter and I have ridden about 5000 miles since then. I am going to replace the gasket with a Cometic one. That will make it easier to take a look inside whenever I want, and prevent future leaks. I wanted to find out what is causing the extra ticking noise that I started noticing in December.
On inspection I found that I have too much end clearance on some of the spindles. There is about .020 end play on most of them. I think when I built the engine and fitted all new spindles I had fitted them in a bit to far and now they are gradually being moved out to the spot where they are happiest. I had them all set for about .003 to .005 clearance and the only explanation for the additional clearance must be the spindles moving. There is no noticeable wear that would increase end play that much. I think the aluminum plate may have been bowed in slightly at each spindle being held out by the spacers about .020 too much. Gradually over 8000 mile the plate has moved the spindles to the spot where the plate is flat. I think that problem was caused by using some washers that were a bit too thin but using a measurement for the position of the spindles that would suit fatter washers. Anyway those problems are easy enough to fix.
The bigger problem is that my rear cylinder inlet cam has worn again. Last year after only about 3000 miles it was worn pretty badly, so I replaced it and the follower with new ones. None of the other lobes or followers had any noticeable wear. They are Terry Prince 105 cams and followers, but I am sure the fault is not with the cams because there has never been any wear at all on the other three lobes. From reading the forum and asking advice I decided this wear was caused by two faults. One was that I had the locking rocker feed bolts supplied by the spares company and the holes in those were too small. I opened them up to 1mm. The second problem was to do with the oil holes in the cams. On the inlet lobes that holes only lines up very briefly each revolution with the hole in the spindle, the exhaust lobes each have oil constantly supplied out that hole. On this forum someone advised connecting the hole in the inlet cam to the constant oil supply by broaching a slot in the bushing, so I did that as well. I think I won't replace the cam this time because this time the wear is a lot less so I will just stone it nicely fit a new follower and try it for another year. Probably the additional oil helped from the two modifications I did. I think what I will do to try to correct the problem is drill out the rocker feed bolt hole a bit more, only on this one. I am thinking I will go for 50% more area than 1mm so that I might get 50% more flow. I use only Amsoil 20W-50 Vee Twin oil, full synthetic.
The other thing that could cause this problem would be a lack of clearance somewhere in that part of the valve train. I checked valve to piston clearance, and clearance on the rockers and valve guides etc. when assembling the engine. It may be that on just this one valve the valve adjuster can hit the inside of the inspection cap sometimes. This adjuster is unscrewed a bit more than the other three. There is one small mark on the inside of the cap.
There is some wear on the follower but the wear on the cam is about .020". Last year I think I had about .050 wear on the cam in 3000 miles and the follower was ruined as well.
Has anyone else had this problem? What were your solutions? This engine runs really well apart from this. It starts easily and it is pretty fast.
Nigel
On inspection I found that I have too much end clearance on some of the spindles. There is about .020 end play on most of them. I think when I built the engine and fitted all new spindles I had fitted them in a bit to far and now they are gradually being moved out to the spot where they are happiest. I had them all set for about .003 to .005 clearance and the only explanation for the additional clearance must be the spindles moving. There is no noticeable wear that would increase end play that much. I think the aluminum plate may have been bowed in slightly at each spindle being held out by the spacers about .020 too much. Gradually over 8000 mile the plate has moved the spindles to the spot where the plate is flat. I think that problem was caused by using some washers that were a bit too thin but using a measurement for the position of the spindles that would suit fatter washers. Anyway those problems are easy enough to fix.
The bigger problem is that my rear cylinder inlet cam has worn again. Last year after only about 3000 miles it was worn pretty badly, so I replaced it and the follower with new ones. None of the other lobes or followers had any noticeable wear. They are Terry Prince 105 cams and followers, but I am sure the fault is not with the cams because there has never been any wear at all on the other three lobes. From reading the forum and asking advice I decided this wear was caused by two faults. One was that I had the locking rocker feed bolts supplied by the spares company and the holes in those were too small. I opened them up to 1mm. The second problem was to do with the oil holes in the cams. On the inlet lobes that holes only lines up very briefly each revolution with the hole in the spindle, the exhaust lobes each have oil constantly supplied out that hole. On this forum someone advised connecting the hole in the inlet cam to the constant oil supply by broaching a slot in the bushing, so I did that as well. I think I won't replace the cam this time because this time the wear is a lot less so I will just stone it nicely fit a new follower and try it for another year. Probably the additional oil helped from the two modifications I did. I think what I will do to try to correct the problem is drill out the rocker feed bolt hole a bit more, only on this one. I am thinking I will go for 50% more area than 1mm so that I might get 50% more flow. I use only Amsoil 20W-50 Vee Twin oil, full synthetic.
The other thing that could cause this problem would be a lack of clearance somewhere in that part of the valve train. I checked valve to piston clearance, and clearance on the rockers and valve guides etc. when assembling the engine. It may be that on just this one valve the valve adjuster can hit the inside of the inspection cap sometimes. This adjuster is unscrewed a bit more than the other three. There is one small mark on the inside of the cap.
There is some wear on the follower but the wear on the cam is about .020". Last year I think I had about .050 wear on the cam in 3000 miles and the follower was ruined as well.
Has anyone else had this problem? What were your solutions? This engine runs really well apart from this. It starts easily and it is pretty fast.
Nigel
