I wonder if anyone can help explain this one? My 100/6 has been modified over the years, little by little so difficult to date when the problem started; years ago I fitted a later BJ8 camshaft, and I think it has been a bit wrong ever since. If I set the ignition timing to the reccommended setting of 10 btdc, it coughs and splutters and hardly moves on the road. So I advance it untill it is too advanced for the starter motor, back off a bit so it runns smoothly. adjust carbs to good mixture and away I go, pulls like a good 'un. but it gets too hot. with just an electric fan fitted, engine idling, the fan never cuts out, it just gets hotter and hotter. with original blades as well, it is controlable at idle, but I can't go up a long hill. At a steady 60 along the flat it maintains reasonable temp, but please don't get to a hill! It has triple SUs and a mallory twin-point distributor. I thought I'd take a close look at it, try to sort it out. Turns out the ignition is set to about 30 btdc, (static) but that is running fine. so could the cam timing be out? checked, and the inlet is opening about 30 btdc also, not the 10 it should be. So I moved the chain 1 tooth round, and now valve and ignition are closer to where they should be. then reading through the manual again I noticed it gives Rocker clearance for valve timing is 30 thou, not the normal 12 thou. I now think that I am supposed to check the valve timing with the rocker set to 30 thou, which will affect the result dramatically. So I put it back to correct cam timing, adjusted the rockers on No1 to 30 thou and checked the valve timing, and got the almost correct result of 10 btdc and exhaust closing 20 atdc.(book says 16 and 21) It also says in the book, timing marking: Adjoining teeth are marked. but mine don't ever line up, I set the chain with 14 links from one mark to the other, as in the picture. So too many things to look at. Any ideas? I changed the front pully, and checked the tdc mark on it to be correct with piston hight. Changed water pump, changed Radiator, checked flow in header tank good. If valve timing is correct, what makes it run with ignition so far advanced? is this the cause of the overheating? and am I now checking the valve timing in the correct fashion? I rotate the engine until the pushrod just pinches, that is starting to open, no? Any help gratefully appreciated.
- posted
16 years ago