Oil tank inspection port
Recently the forum has seen a flurry of activity concerning the cleaning out of UFMs via an inspection port let into the top of the oil tank. As many of you like to make parts I thought that I would put the design of one of these that I came up with several years ago. Originally I wanted two for my own use and local Kent and Sussex Section member Eric Priestly also wanted a couple so, as he has the necessary skills and equipment, he offered to make a few for our own use. These were used on two of my bikes and two of his. Later, another Kent and Sussex Member, Paul Champion, asked if he could have the design to make one for one if his own bikes. The original design meant making the ‘ring’ which has to be fitted into the top of the oil tank robust enough so that when it was welded in it did not weaken the tank in any way. It was 2.5” diameter and 0.5” thick. I designed the internal thread to be the same as that of the exhaust ports and rocker inspection caps. The reasoning behind this was that the welding was likely to cause some distortion of the internal thread and people were likely to have a 1.875 x 20 tpi tap for cleaning up the various threads in the cylinder heads. This proved to be necessary as we found that both brazing or silver soldering still caused enough distortion to require the threads to be cleaned up. It is possible that a modern TIG welder might circumvent this problem. With this experience Paul decided to follow a slightly different route and instead made a large flange to the insert and glued and screwed this to the top of the tank.
Below I will show three drawing which should allow anyone with the skills and equipment to make their own and they can choose which type to produce. Note that the centre of the later design is exactly the same as the earlier design; it is only the flange, which contains four countersunk holes, which is different. It should also be noted that the slot in the top of the screwed plug was designed to take the curved end of either a K1 or K3 spanner for tightening or undoing. Not all these spanners are the same thickness so ensure that you check the thickness of the spanners before finishing the slot.
Here is the drawing for the plug which is the same whichever design is chosen.
Here is the design for the original insert to be fastened into the top of the oil tank. It is 2.5” diameter and 0.5” deep
.
Note that the specification of the four countersunk holes has not been made as one can make these to fit whatever screws are chosen, e.g. self tapping, machine screws in to tapped holes etc. Several types of adhesive could be used. A thickened epoxy would suit if the metal can be guaranteed grease free or one of the modern structural metal to metal mastics, black RTV would be one I would try.
The 'o' ring, which is intended to fit into the groove below the top flange of the plug was a 3mm cross section by 45 mm I.D.
Next page shows four images of Paul Champion’s mod. All pictures due to Paul.
Recently the forum has seen a flurry of activity concerning the cleaning out of UFMs via an inspection port let into the top of the oil tank. As many of you like to make parts I thought that I would put the design of one of these that I came up with several years ago. Originally I wanted two for my own use and local Kent and Sussex Section member Eric Priestly also wanted a couple so, as he has the necessary skills and equipment, he offered to make a few for our own use. These were used on two of my bikes and two of his. Later, another Kent and Sussex Member, Paul Champion, asked if he could have the design to make one for one if his own bikes. The original design meant making the ‘ring’ which has to be fitted into the top of the oil tank robust enough so that when it was welded in it did not weaken the tank in any way. It was 2.5” diameter and 0.5” thick. I designed the internal thread to be the same as that of the exhaust ports and rocker inspection caps. The reasoning behind this was that the welding was likely to cause some distortion of the internal thread and people were likely to have a 1.875 x 20 tpi tap for cleaning up the various threads in the cylinder heads. This proved to be necessary as we found that both brazing or silver soldering still caused enough distortion to require the threads to be cleaned up. It is possible that a modern TIG welder might circumvent this problem. With this experience Paul decided to follow a slightly different route and instead made a large flange to the insert and glued and screwed this to the top of the tank.
Below I will show three drawing which should allow anyone with the skills and equipment to make their own and they can choose which type to produce. Note that the centre of the later design is exactly the same as the earlier design; it is only the flange, which contains four countersunk holes, which is different. It should also be noted that the slot in the top of the screwed plug was designed to take the curved end of either a K1 or K3 spanner for tightening or undoing. Not all these spanners are the same thickness so ensure that you check the thickness of the spanners before finishing the slot.
Here is the drawing for the plug which is the same whichever design is chosen.
Here is the design for the original insert to be fastened into the top of the oil tank. It is 2.5” diameter and 0.5” deep
.
Note that the specification of the four countersunk holes has not been made as one can make these to fit whatever screws are chosen, e.g. self tapping, machine screws in to tapped holes etc. Several types of adhesive could be used. A thickened epoxy would suit if the metal can be guaranteed grease free or one of the modern structural metal to metal mastics, black RTV would be one I would try.
The 'o' ring, which is intended to fit into the groove below the top flange of the plug was a 3mm cross section by 45 mm I.D.
Next page shows four images of Paul Champion’s mod. All pictures due to Paul.
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