throttle body vacuum caps

[woodgeek]

Sorry for the stupid question. What size are the vacuum caps on the K100 throttle body? I'm at work ordering various rubber bits for the K and don't have anything handy to measure. I also don't want to pay 2.73 each for BMW vacuum caps. They look like they're made from rubber which should last about a year before hardening.

[alabrew]

Don't know the size, but I did find a pack of various sized vacuum caps at auto zone and it had a few that fit plus I now have Murphy's Law that I'll never need another since I have replacements on hand =-}.

[Laitch]

They look like they're made from rubber which should last about a year before hardening.

On a well-maintained bike not left out unprotected in the elements, the originals can last a couple decades before hardening.

[woodgeek]

On a well-maintained bike not left out unprotected in the elements, the originals can last a couple decades before hardening.

Are you hinting that I should pony up for genuine bits from the mothership?  :2thumbup:

[Laitch]

Are you hinting that I should pony up for genuine bits from the mothership?  :2thumbup:

Nope.

[Martin]

Virtually all of the auto stores have those Champion in OZ rotatable stands with small packets of bolts, nuts, washers and various other small parts. They can be found on these stands.
Regards Martin.

[woodgeek]

[emoji106]

[RobP]

My expeditious solution was to use a 1/2" length of silicon rubber hose with a dab of black RTV at the end.

[woodgeek]

My expeditious solution was to use a 1/2" length of silicon rubber hose with a dab of black RTV at the end.

I've done that before too.  :2thumbup:

[K1300S]

Don't know the size, but I did find a pack of various sized vacuum caps at auto zone and it had a few that fit plus I now have Murphy's Law that I'll never need another since I have replacements on hand =-}.

this.  any chain autoparts store carries vacuum caps.  cheap.

[Chaos]

my bike has vacuum caps? 

[woodgeek]

my bike has vacuum caps?

[emoji23]

[Chaos]

I know the Ural has them.  I once kick started it and it backfired, blowing one of the carbs off it's perch and launching it's vacuum cap into near earth orbit. Popped the carb back on and improvised a temporary cap out of duct tape.  Always an adventure with that rig, the beemer is downright boring.  :eek:

[woodgeek]

I know the Ural has them.  I once kick started it and it backfired, blowing one of the carbs off it's perch and launching it's vacuum cap into near earth orbit. Popped the carb back on and improvised a temporary cap out of duct tape.  Always an adventure with that rig, the beemer is downright boring.  :eek:

The Ural looks like fun. Do they all have chairs? The K’s vacuum caps are on the throttle body, in case you weren’t being facetious. [emoji6][emoji106]

[Chaos]

amazingly, in 32 years and over 200,000 miles I have never messed with any part of the fuel system other than the filter.  I assumed the caps were for some tuning function the wizards in Germany performed and set for life.

[Chaos]

there are solo Urals but they are rare, discontinued a couple years ago.  the model that comes with a telescopic fork makes a decent road bike with the tub off, the models with leading link forks not so much.

[woodgeek]

I assumed the caps were for some tuning function the wizards in Germany performed and set for life.

You pull off the vacuum caps and hook up some vacuum gauges to sync the individual throttle bodies—a process that’s not much fun. [emoji23]
Luckily you only need to sync if you’ve messed with something, like installed new throttle body boots, etc.

[woodgeek]

there are solo Urals but they are rare, discontinued a couple years ago.  the model that comes with a telescopic fork makes a decent road bike with the tub off, the models with leading link forks not so much.

A neighbor of ours had a sidecar Ural. Looked really cool—sort of like a two person Willy’s JEEP.


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[wally.fisher]

4mm or 5/32", look on fleabay for silicone caps they also come in colours.


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[jay1622]

This post brought back a memory I never would’ve revisited if it weren’t for it.   You know those little white end caps you put over the sharp metal ends of closet shelving? Years back I ended up using one of these in a pinch, and it worked so well I never bothered replacing it. It did get a coat of black permanent marker though. Not sure if the OP ever made a decision, but considering how darn touchy these things get when you experience a vacuum leak, I’d get the OEM ones if ya can’t find something that fits just right.

[woodgeek]

This post brought back a memory I never would’ve revisited if it weren’t for it.   You know those little white end caps you put over the sharp metal ends of closet shelving? Years back I ended up using one of these in a pinch, and it worked so well I never bothered replacing it. It did get a coat of black permanent marker though. Not sure if the OP ever made a decision, but considering how darn touchy these things get when you experience a vacuum leak, I’d get the OEM ones if ya can’t find something that fits just right.

Thanks for the tip. I'm going to pick up some silicone caps from Amazon or eBay but using the closetmaid closet shelving caps is genius! :yow :2thumbup:

[Martin]

The caps on the thick plastic coated coat hangers might also fit.
Regards Martin.

[K1300S]

You pull off the vacuum caps and hook up some vacuum gauges to sync the individual throttle bodies—a process that’s not much fun. [emoji23]
Luckily you only need to sync if you’ve messed with something, like installed new throttle body boots, etc.

actually, the synch process is super easy.  takes about 5 mins.  i do my K75s's at least once a season.....and at least one of the TB's usually needs a little tweak.  this is not a set and forget item.  it is part of the normal maint routine.

[woodgeek]

actually, the synch process is super easy.  takes about 5 mins.  i do my K75s's at least once a season.....and at least one of the TB's usually needs a little tweak.  this is not a set and forget item.  it is part of the normal maint routine.

Good to know, thanks! Glad I kept my CarbTune.  :2thumbup:

[K1300S]

Good to know, thanks! Glad I kept my CarbTune.  :2thumbup:

yep, carbtune is where it is at.  hang it upside down for better readings...