Post by ap951 on Jan 28, 2012 13:09:22 GMT -5
I want to share a fix that I came up with last spring. After many attempts I could not repair the vacuum leak internal to my petcock & when parked it would always weep gas into the carb. I decided that I no longer wanted the vacuum-open/spring-closed action of the stock unit. I really wanted it to work like the petcocks on my other old bikes. The stock Re5 petcock has 3 settings: Prime-Open-Reserve. I came up with a fix that converts this to: Closed-Open-Reserve.
I removed the plate in the back & used it as a template to fabricate a brass plate that I used to replace the sock plastic unit. For this I purchased a piece of .062" thick brass plate from my local hobby store. You can use other materials/thicknesses however I chose this because I'm partial to brass & it was easy for me to work with. I used a sharpening stone to lap all of the surfaces flat. I also purchased some good quality gasket material & fabricated two gaskets. (again using the stock plate as a template)
I used a small wire brush on my Dremel to thoroughly clean out the cavities on the backside of the control knob. I used JB weld (a little lean on the hardener to keep it more fluid and resist air bubbles) to fill the cavity that is shaped as the radius. Again I used a sharp file to remove the access and then lapped the surface to a smooth flat finish. I replaced the seal behind the knob with a new one and put a very light coating of anti-seize compound on all of it's surfaces. This will make the knob turn smooth & easy.
I reassembled the unit leaving out the stock plastic plate with it's diaphragms & spring. The petcock now works like a conventional unit: Closed-On-Reserve. I still run my vacuum line so the bike looks completely original. An added bonus is that the fuel flows much better as the stock diaphragm internals are restricting to the fuel flow & as many here know Re5's are thirsty. After a year I took it apart to inspect & the JB weld has not changed at all. When this is turned to the closed position it does not leak one bit.
I removed the plate in the back & used it as a template to fabricate a brass plate that I used to replace the sock plastic unit. For this I purchased a piece of .062" thick brass plate from my local hobby store. You can use other materials/thicknesses however I chose this because I'm partial to brass & it was easy for me to work with. I used a sharpening stone to lap all of the surfaces flat. I also purchased some good quality gasket material & fabricated two gaskets. (again using the stock plate as a template)
I used a small wire brush on my Dremel to thoroughly clean out the cavities on the backside of the control knob. I used JB weld (a little lean on the hardener to keep it more fluid and resist air bubbles) to fill the cavity that is shaped as the radius. Again I used a sharp file to remove the access and then lapped the surface to a smooth flat finish. I replaced the seal behind the knob with a new one and put a very light coating of anti-seize compound on all of it's surfaces. This will make the knob turn smooth & easy.
I reassembled the unit leaving out the stock plastic plate with it's diaphragms & spring. The petcock now works like a conventional unit: Closed-On-Reserve. I still run my vacuum line so the bike looks completely original. An added bonus is that the fuel flows much better as the stock diaphragm internals are restricting to the fuel flow & as many here know Re5's are thirsty. After a year I took it apart to inspect & the JB weld has not changed at all. When this is turned to the closed position it does not leak one bit.
