Head Gasket Problem
Posted: Mon Mar 25, 2019 10:28 am
A friend of mine has just bought a 1959 Model 20 - very nice looking bike that's obviously had time and money spent on it. Yesterday was the first day he was in a position to ride it, as he works away in the week, so we decided to go over to my bike club's breakfast meet, then have a longer ride back so he can get used to it; it's his first classic bike.
Well, we only got about 4 miles and one of the head gaskets went. The 3rd member of our small group rode back to get is bike trailer, and we took it back to my garage so I can work on it in the week. I made a start yesterday afternoon, just by removing the seat and tank, and I see that the heads are held on with domed nuts. Is this normal? On my 650 they are normal nuts. Surely a domed nut could bottom out, giving the impression that it is torqued up correctly, whereas it is anything but? The PO did tell him that the gaskets are composite, and that he had done the usual torque routine with these, and the next step was to get some miles in and then torque them again. I have composite gaskets on my 650 and have followed the same torque/retorque sequence with no problems.
As an aside, after getting the bike back to my place and taking its owner home, I decided to take mine back out. The kickstart broke! Do you ever get the impression that the Gods are trying to tell you something?
Malc
Well, we only got about 4 miles and one of the head gaskets went. The 3rd member of our small group rode back to get is bike trailer, and we took it back to my garage so I can work on it in the week. I made a start yesterday afternoon, just by removing the seat and tank, and I see that the heads are held on with domed nuts. Is this normal? On my 650 they are normal nuts. Surely a domed nut could bottom out, giving the impression that it is torqued up correctly, whereas it is anything but? The PO did tell him that the gaskets are composite, and that he had done the usual torque routine with these, and the next step was to get some miles in and then torque them again. I have composite gaskets on my 650 and have followed the same torque/retorque sequence with no problems.
As an aside, after getting the bike back to my place and taking its owner home, I decided to take mine back out. The kickstart broke! Do you ever get the impression that the Gods are trying to tell you something?
Malc