Desmog or not?

[joker]

Since I am going to have the fuel tank and the air cleaner box out this winter, what are the benefits if any to desmogging the Valkyrie? What I’m facing right now is several cracked dry rotted vacuum tubes.

[John Schmidt]

Well, you sorta answered your own question when you stated you're facing cracked tubing. Desmogging doesn't boost performance of the Valk, but it does do away with future vacuum leaks due to degraded tubing. With the tank and airbox removed, that's the time to do it. Just keep one of the vacuum ports available for the petcock if you're running a vacuum operated unit such as the OEM.

[hubcapsc]

I desmogged. And I helped Stanley Steamer replace his vacuum lines.

I'd not desmog if I had it to do over... there's no going back...

-Mike

[joker]

Mike, why would you not do it over again? Just curious

[hubcapsc]

Mike, why would you not do it over again? Just curious

It doesn't make your bike run any different or better... having both desmogged
and replaced vacuum lines, I'd just rather go with the vacuum lines if I
could do it again. Pretty much the only way to get the chrome air tubes
off is to destroy them... there's still a vacuum line and some other carb
vent lines in there, so on the plus side of desmogging, there's more room
to get your hands in there when you need to check/replace them. You have
to pop the intake runners off every now and then to replace the Orings, that's
easier too...



-Mike

[Tfrank59]

I haven't desmogged yet, though I have the kit and I guess the know-how.   If I ever I see a change in engine performance that I can attribute to a vacuum leak or whatever (my engine runs perfectly at 66k) I'll do the desmog.  I got too many other matters to attend to, and then there's bike maintenance for two bikes--life's too short

[98valk]

100lbs less lbs =  1/10 in the 1/4.

desmog lessens chance of hose failure/vacuum leak and/or pair valve failure on the road.
losses 3lbs and one can do the math for faster 1/4.

with other weight reductions I've done, 3 lbs is a nice reduction.

[old2soon]

desmog done and if I git another Valkyrie I'd do er again-desmog.  RIDE SAFE.

[Roidfingers]

No going back ????? Just plug the chrome lines. No need to cut. Then if you want to go back you can.

[sdv003]

Just finished a desmog a month ago.  There's lots more room, I only had to destroy the one tube, and the smog related vacuum issues are gone.  I also added a dan-marc valve and made the petcock manual to get rid of that last vacuum line.  I don't think the dan-marc would have fit without desmogging, but I could be wrong.  Simpler is better in my book, and having none of the desmog parts makes it simpler, especially since I don't think Nevada will be checking for 20 year old MC smog equipment any time soon.

[Houdini]

I desmogged both of mine.  The first one, my IS, I destroyed the front right tube, on my Standard I just capped it so I can re-smog if I so desired.  I doubt I'll ever put any of it back on, but I can....

[Jess from VA]

Short of some nitwit Govt inspection that required OE everything emissions-wise (and they'd never do it on our old bikes now), why would anyone want to ever install all that crap again?

But it's not like a desmog means you never have to worry about vacuum leaks again.  I've blown off (or in two) several of those caps on the inside intake nipples, and man, talk about a huge backfire.  People thought I was shooting at them.     

[Fazer]

I did the whole desmog thing when installing the Dan Marc fuel shut off.  Taking out the chrome lines is easy if you are not worried about destroying them, and as Jess said, who would ever want to put that crap back in???  Plugging the holes is easy with 14mm freeze plugs.  I made a couple of alum covers for the bottom connections and did have to loosen the left side exhaust to gain access, but with the correct wrenches even that may not be necessary.  I think the whole engine look is enhanced without all those chrome tubes running everywhere.   The process is well described in shop talk and once you start, is very intuitive.

BonS used to sell really nice vacuum caps with his digisync.  You could buy the caps separately.  I am sure you can find him on the board and he may still have some.

[98valk]

for the top cylinder head holes I filled them with some steel epoxy and then used a shortened 9/16" course thd bolt. tapped the hole.  painted bolt top engine silver.  made aluminum plates for the bottom holes reused the gaskets.  after 40k miles zero leaks or problems.