Rebuilding Petcocks & Carbs

[sail4free]

Oh, and running inline fuel filters on these bikes is a really good idea ... the petcock tower filters just aren't enough, IMO.

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I agree -- seems like many others do too -- perhaps a bigger improvement over the OEM setup than we realize? It just doesn't seem to take much at all to plug these '79 carbs -- they have been a constant battle. So I'm newly committed to running fuel stabilizer 24/7/365 *and* making sure this girl NEVER sits more than a week(!) without running her for a while.
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I've lost all trust even in the OFF position . . . I worry any day I don't ride that fuel is slowly dripping into the crankcase . . . plotting to make my life suck. Even with a new rebuild kit, how long can we trust these petcocks to actually DO what they say they're doing?
JIM P. ~ BOISE, ID
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[DiverRay]

IF the "O" ring with the four holes in each are in good shape, you should NOT have a leak. Specials DO have an OFF position that the standard does not have.

[sail4free]

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Interesting . . . so the Standard is 100% dependent on the octy to stop fuel flow? Like the newer bikes where the vacuum diaphragm is built into the petcock? We're putting new rebuild kits ($31/32 a pop!) into the petcocks (ordering them online tomorrow). Tyler sent me a pic of my freshly rebuilt carbs -- looking good! He replaced the Phillips screws with stainless steel allen-head bolts. He has a spare tank he can use for a test fire . . . reminds me . . . how critical is a cooling fan when tuning this time of year? When it's still relatively cool out? He set up close on the bench and has the set of four vacuum gauges for the sync.
JIM P. ~ BOISE, ID
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[IanDMacDonald]

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Interesting . . . so the Standard is 100% dependent on the octy to stop fuel flow? Like the newer bikes where the vacuum diaphragm is built into the petcock? We're putting new rebuild kits ($31/32 a pop!) into the petcocks (ordering them online tomorrow). Tyler sent me a pic of my freshly rebuilt carbs -- looking good! He replaced the Phillips screws with stainless steel allen-head bolts. He has a spare tank he can use for a test fire . . . reminds me . . . how critical is a cooling fan when tuning this time of year? When it's still relatively cool out? He set up close on the bench and has the set of four vacuum gauges for the sync.
JIM P. ~ BOISE, ID
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You may be adding/confusing words on accident, but the Standard is solely relying on the "petcock", and the vacuum of the engine to stop the flow of fuel (contingent upon clean & functioning carbs).

[DiverRay]

how critical is a cooling fan when tuning this time of year? When it's still relatively cool out? He set up close on the bench and has the set of four vacuum gauges for the sync.

Your mechanic WILL need a cooling fan. The engine can overheat quickly, even when cool outside. Sitting still, it's all convection, and the fins are 90 degrees out for working well with that. Figure 4 minutes to warm up the engine, and about 10 to 12 minutes to sync. These engines have problems after about five minutes without airflow.

[sail4free]

Thanks!

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I'll be sure to let him (Tyler) know. I should be able to borrow a fan of some kind from work
JIM P. ~ BOISE, ID
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[DiverRay]

I use a cheap 20" box fan. Put it on medium speed, on a box to elevate it, and off to one side of the front forks. Also works well to cool down the house if it gets too warm.

[sail4free]

Thanks Again!

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I'll let him know that too )
JIM P. ~ BOISE, ID
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[ViperRon]

When doing the petcocks clean and polish the surfaces clean and the kit will seal better. Sometimes the parts that screw together can suffer from warping which can be checked with a straight edge. If a plate is warped you can gently sand it flat again. Make sure the little hole behind the diaphragm is clear it allows the diaphragm to restore. There are picture illustrations here on the site you just have to search for them.

I do not wait for my petcock to leak I take it apart during the winter each year and clean it rubbing a thin film of grease on the rubber to clean it. Not a lot of grease just get the white film off and make it all shinny again. Helps everything seal good and is very minimal contamination to gas. This ethanol takes a toll on all plastic and rubber so one good cleaning a year insures I am not at a rally dealing with petcock issues.

[cmpnbd2]

petcocks universal

will universal petcocks with 34mm adapter from partsnmore work on my 80 xs1100 lg mns?

[sail4free]

Petcock Rebuild Kits Ordered!

When doing the petcocks clean and polish the surfaces clean and the kit will seal better. Sometimes the parts that screw together can suffer from warping which can be checked with a straight edge. If a plate is warped you can gently sand it flat again. Make sure the little hole behind the diaphragm is clear it allows the diaphragm to restore. There are picture illustrations here on the site you just have to search for them.

I do not wait for my petcock to leak I take it apart during the winter each year and clean it rubbing a thin film of grease on the rubber to clean it. Not a lot of grease just get the white film off and make it all shinny again. Helps everything seal good and is very minimal contamination to gas. This ethanol takes a toll on all plastic and rubber so one good cleaning a year insures I am not at a rally dealing with petcock issues.

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That sounds like a good approach -- a little diligence once a year can save a LOT of grief later. If one can avoid ethanol completely, even better. I just ordered these kits -- hope they're the right one!
http://tinyurl.com/no8xj9r
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I'll share your technique with Tyler (my mechanic). I believe that on my '79 Special, there is no diaphragm in the petcock to worry about -- though a new one comes with each kit ) Are there other preventive maintenance things that we should do once a year to minimize grief? Thanks for your help!
JIM P. ~ BOISE, ID
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[Prisoner6]

I just ordered these kits -- hope they're the right one!
http://tinyurl.com/no8xj9r
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I'll share your technique with Tyler (my mechanic). I believe that on my '79 Special, there is no diaphragm in the petcock to worry about -- though a new one comes with each kit )

Hey, Jim -

The kit in your link is for the Standard petcocks. The kit you need for the Special petcocks is this one:

XS1100 Special Petcock Rebuild Kit

The kit comes with everything you need to rebuild both petcocks. The diaphragm included in the Special kit is for the Octy ...

But since you are deleting the Octy, you won't be using the diaphragm.

[DiverRay]

If you just order them, send a PM to the seller and tell him what you need the kits for. He will be able to send the proper one out, before the wrong ones get sent with any luck! He IS in Florida, so he's 3 hours ahead of me.

[sail4free]

Thanks! Crap!

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Thanks Prisoner6 and DiverRay -- Crap! -- You'd think I'd know enough to check with you guys *first* -- next time! . . . (could've saved myself some money too!). I sent georgefix a message and a link to the right ones:
http://www.ebay.com/itm/XJ1100J-XS11...item541c6669af
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With his 99.8% approval rating (99,000+ transactions), pretty sure we'll be able to work it out
JIM PETERSON ~ BOISE, ID
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[DiverRay]

He's a good guy. I get almost all my fuel related stuff from his ebay store.