Vacuum advance and pluse generator (VACUUM ADVANCE REBUILD)

[danf]

I bought the one from my friend, and it held pressure just with sucking on the hose, the weights stay open, mine would not..I will operate later, I want to figure out how these work... I already have the new one on the bike..Yes.. :music3:

 

[danf]

Surgery went well and the patient is in the recovery room, expecting a full recovery..I carefully cut and removed the halves of the canister [dremel] discovered four small holes in rubber diaphram, used blue silicon gasket sealer to cover the holes and let dry a few hours in a warm place, then I cut some small squares of my latex gloves to make patches to cover again, I covered the patch with more silicon and applied over hole area, let dry a few hours and put the unit back together, placed a welders clamp on to hold together and used jb weld to seal the sides of the halves closed , it now has full vacuum that holds.. I will know more tomorrow when I put it in the unit..It might work better than the one I got from my friend.... Lots of rust inside, man... used brake cleaner again to clean up, If any of you guys out there try this, try to leave a lip on the sides of the halves, and make a note of the position of the hose nipple and the housing so it goes back on just how it came off.. :grin: The screw in the center on the rear is for adjustment of the spring that's inside the can...If these parts can't be bought maybe we can fix them.. :grin: You could also use rubber cement for yor patches..I'm sure..

 

[dan filipi]

That's great beav!.
We don't mind long posts.
Success is what it's all about and we can excited too over these old beast!

 

[Arnold]

I'm interested in following your lead, Little Beaver, and seeing what's inside my vacuum advance. I have a mysterious condition that causes my GL1100 (1981) to misfire as I transition from idle to higher revs. How easy is it to take the vacuum advance lid off once you remove the rear wheel, shocks, and swingarm? Did you take any photos?
I think the previous owner thought there were problems with the vacuum advance, as he placed a small brass jet in the advance hose to restrict flow. I removed that jet and installed a new vacuum hose. :headscratch: It's all very mysterious to me.

 

[danf]

That's great beav!.
We don't mind long posts.
Success is what it's all about and we can excited too over these old beast!

I was just thinking next time I might place some clips or some sort or crimps to the sides before placing the jb weld down, double strong to keep the sides closed tight..

 

[danf]

I'm interested in following your lead, Little Beaver, and seeing what's inside my vacuum advance. I have a mysterious condition that causes my GL1100 (1981) to misfire as I transition from idle to higher revs. How easy is it to take the vacuum advance lid off once you remove the rear wheel, shocks, and swingarm? Did you take any photos?
I think the previous owner thought there were problems with the vacuum advance, as he placed a small brass jet in the advance hose to restrict flow. I removed that jet and installed a new vacuum hose. :headscratch: It's all very mysterious to me.

It's easy access, there's one bolt on the top of the housing case you might need a 1/4 drive and socket[8mm] with a small ratchet and note where the bolts come out from, one doesn't have a washer [lower left] of case for good cause it would hit the weight if it did, it's a good idea to check and see if everything is moving, suck on the hose and watch the baseplate move once you have the cover off, mine didn't move so it came out, If it moves it should hold open while sucking on it, don't touch the center bolt with the plastic shaft on it, no need to it goes to the part inside, the unit comes out strange, you gotta angle it just right to clear everything by the frame bar. It's easy..I would bet there are a lot of these units not functioning on bikes today.. This is my best way to discribe how the advancer unit works like Dan said the more vacuum the more it opens, it's like air under a balloon if you take the pressure off the balloon drops,.I'm no expert so don't go label me one guys...Get you a second one to mess with like I did before you go operating and such... :smilie_happy:

 

[danf]

My air nipple for the hose to the unit what rusted shut when I first started. So make sure it's cleaned out with a firm small wire first thing..Wow I wonder how my bikes gonna run now..I'll take photo's the next time around and I will post them if that's ok.. :grin:

 

[joedrum]

beaver it started out me teaching you guidedense .....now you taught me something ......great thread beaver .....this is one thing we havnt realy went from a-z with....the rebuild of the vacume and the scew adjustment is big to me .....from the common beleif that the timing is unadjustable to theres all kinds of adjustment and very preceice to ....... :good: k: :headscratch: :mrgreen:

 

[AApple]

:clapping: :clapping: :clapping:
Yes indeedy!! Very informative thread here! Thanks for sharing, and taking the time to do the leg work, littlebeaver!!! k: :hi:

 

[dan filipi]

..I'll take photo's the next time around and I will post them if that's ok.. :grin:

Oh abolutely! Photo's make all the difference.
Post photos of what you've done already in the gallery also.

 

[danf]

:clapping: :clapping: :clapping:
Yes indeedy!! Very informative thread here! Thanks for sharing, and taking the time to do the leg work, littlebeaver!!! k: :hi:

Thanks guys, I'd use the special heavy duty cut off wheel sold at Home depot or lowes for dremels, it's my favorite cut off tool . I put unit back in the housing this morning, put the pump on it and it goes full open and bleeds off, if you suck constantly on the hose it stays in the open position, Yes...Now I hope the silicon and patch holds well and the jb weld looks great that sucker is sealed.. :yahoo:

 

[Arnold]

Question: Was it necessary to remove the gas tank to access the vacuum advance system?
:read:

 

[danf]

Question: Was it necessary to remove the gas tank to access the vacuum advance system?
:read:

No reason to remove tank, only swingarm.

 

[danf]

Here's a question for you guys out in the World of Honda, does the air advance unit on the older cars like [80's] honda's have a vacuum advance mechanism like this one with the same size arm attachment, if so you might be able to use the good diaphram out of it using this procedure, if your diaphram has 4 holes in it like mine did you might investigate other avenues..But i'm Mr. El Cheapo dude and like to try fixing things..If Honda does have another diaphram that fits this, then that itself would be a break thru..

 

[danf]

Here are a few photo's but not of the insides, I am not going to reopen it now it's been sealed shut, but take my word to heart it's repaired now. :grin:View attachment 3View attachment 2View attachment 1 Rock on dudes

 

[dan filipi]

It definitely looks sealed.
Now if the rubber repair holds up it's a done deal.
Nice :music:

 

[joedrum]

beaver you woulnt beieave how timely this thread was for me ......you did all the leg work on things i wasnt sure of yet and now i dont have to everything done :clapping: :good: :headscratch: :yahoo: :mrgreen:

 

[danf]

beaver you woulnt beieave how timely this thread was for me ......you did all the leg work on things i wasnt sure of yet and now i dont have to everything done :clapping: :good: :headscratch: :yahoo: :mrgreen:

Joe I have a few more idea's up my sleeve for other fixes.. :yahoo:

 

[danf]

It definitely looks sealed.
Now if the rubber repair holds up it's a done deal.
Nice :music:

Dan when I started this I thought that the hand pump would pump up and hold everything and not bleed off, I read that somewhere, that's not the case because the unit is supposed to bleed off that's why that hole is on the back, however if you suck on the hose and keep suction on it and it stays open then your good..Here's what I'm gonna do, I have my friends on the bike now, I'm gonna start the bike with his attached then take off the hose and place it on the one I repaired and hold it in my hand to watch and see if it stays open or what it does..How's that for a test.. :grin: The hand pump is good for one thing, that's checking to see if it's opening up fully at 3.9hg as specs. say other wise you don't need that silly toy..Mine opens to specs. now..[mitty vac] is the pump I used..

 

[danf]

If I'm you guy's I'd love to see the insides of the canister, so this is just for you guys.View attachment 1 I hope this helps someone who may have been curious about it. I put a full layer because I don't want to worry about it not holding I will put a layer on the inside too.. I think it will work. :smilie_happy: