danf
Well-known member
I found something out today with my friends oem vacuum advance canister, if you pump it[mitty vac] up it bleeds off until it gets to the 3.2 hg's[it was actually at 2.2] area then stops there at that point.. The freakin thing is designed to bleed off down to the correct settings..However my friends first still leaked down after that mark really slowly, I found the leak came from the seal on the rear of the cannister where you set the adjusting screw inside the unit..Problem solved on the leak.. Once I pump it up it bled down to 2.2hg and I thought, I will just cover the end with my thumb and try it again, bingo. it stopped the gauge or stop the leak..Now I learned what the adjuster screw in the can is for, it adjusts the hg number when the air bleeds down, if you screw it in the readings will go up, so screw it in down some and pump it up, now the reading will be higher on the pumps gauge like maybe 4.0 hg , if you back it out it will drop it. it's supposed to be 3.2 hg[Mine is now] for 81's on up and 3.9hg for 80's so that's something I learned today[ The Adjusting Screw]..The rear set screw must be sealed good to avoid leaks in the future once set correctly..My aftermarket one doesn't bleed off air at all period, while attached to the pump.. If you pump it hard to 6.0hg or even 10hg it will stay there you shouldn't ever get that much vacuum on this bike I wouldn't think, I put the new canister on the bike today, It Fits... Yeh,, I was worried about that..No problem.. So now I have two good canisters...Yes.. and I educated myself too..I just want to help the next guy..The guy that doesn't know or is unsure.. I sure didn't know when I started messing with this, but now I know more about it..I'm gonna bet I feel the difference once the bike is reassembled..cool.. later :grin: