Hi all,
Yes I'm still wrestling with the running of the bike.
Can anyone help me solve the problem I’m having with my bike. It does between 5 to 13 miles before it suddenly stops. The following day it starts quite easily. Between 1 and 20 kicks, and runs quite nicely in the garage. I have now stripped it down again to have a look at the seals, because when I took a pressure and vacuum test reading they were very low and very inconsistent. I.e. 40 psi near side and 60 psi far side and varying. At the end of last year, the readings were 130 psi in both cylinders. This reading was taken just after a rebore. Can any body tell me what the expected cylinder pressure should be? With my limited knowledge the seals appear to be O. K. I have sent off for some new ones, which I intend to fit when they arrive. Having stripped it all down, I can see in the centre of the casing, an oil hole. It comes from the top of the casing on the near side, to the centre lip that separates the bearing from the seals between the two fly wheels. On the far side there is a horizontal hole that goes from the bottom of this oil way to the near side. Is this how it should be? The reason being, I think this would allow each cylinder to loose compression in the sump. Also I can’t see how the outside second oil seal would get any of the oil from this hole. Does this matter? As the oil is in the petrol, and so all bearings and seals are lubricated when the bike is running, which seems to make this oil way redundant?
In trying to trace the problem with lack of compression, I have pressurised the sump and used soapy water around the joints. I have also tried a smoke test. Nothing showed up with either test. When taking the cylinder heads off, the near side cylinder head gasket appeared to have been leaking slightly. I had originally torqued up the heads using the 18 Ft. Lbs reading I found on this sight. This appears to be very low to me, as my torque wrench starts at 20 Ft. Lbs. I then tightened up the heads to 30 Ft. Lbs and used Wellseal on the gasket to try and make doubly sure that the heads were not leaking. Before stripping it down I tightened down the heads by hand and checking the result with the torque wrench. This was 40 Ft. Lbs. The heads were machined flat at the time of the rebore, and they do appear to be O.K. now.
Finally. When the bike stops, it appears to me to have run out of petrol? There is plenty in the tank, and the little hole in the petrol cap is nice and clear, and I have made sure that the seat does not block it. I have now purchased another carburettor off EBay, and have used this one to compare. This made no difference.
In the strip down I have removed the exhaust pipes and stood them vertically in the corner of the garage, there is now quite a large black puddle of petrol/oil under them. Would this be quite normal as the bike is not working properly?
Any help or suggestions for me to try would be much appreciated.
John