chop almost done, question on vacuum for special tank on standarad

[lostsoul74]

well, this old beater started off as a 78 standard full dresser. Picked it up for 300 bucks, mechanically sound, a bit ugly. Stripped her naked, chopped the rear, solo seat, drag bars, 5 1/2 harley light, etc. Just painted yesturday and wetsanded this morning, came out decent, but i wouldnt recomend ebay (trinity) paint again. The special tank i had came with everything, petcocks, cap, etc.
Went to install just now, the shorter front hose just barely reaches the front of the petcock on the special, and a bit small, have to force it on. But cant get it running right, appears to be gas coming out of hte carbs. I'm also assuming i no longer need the vent hose either. I've searched here, and see something about vacuum difference between the two. I see lots of stuff about a standard tank on a special frame, but not much versa. Can you guys save me the time of guesswork and tell me exactly what i;ve got to do, what hoses go where? do i need to extend hte shorter smaller hose to go on the back of the petcock. thanks in advance gents.
All thats left now really, is to slap some red cherry bomb mufflers on (as you can see, mine broke the other day), and paint the rear rim red with a wide whitewall.



http://a670.ac-images.myspacecdn.com...876b5e5595.jpg

[psycoreefer]

Special petcocks are "manual" ie no vacuum control like the standard petcocks. From memory the rear port flows gas in the ON/Reserve position and the front port flows gas in the Prime position. Neither should flow gas when in the Off position. You'll likely need to pick up some new/longer fuel hoses also.

What you need to do is plug off the vacuum hose that went to your old petcocks, you don't need it anymore and if you don't plug it its a vacuum leak. You'll also be plugging off the line that comes from the front port on both petcocks, you won't need that either.


Take the lower hose from each pair of carbs and hook it to the rear port of the petcocks. You can hook left carbs to left petcock or left to right, then hook the other pair of carbs to the other petcocks rear port, or pick up some T's and hook them all into the same line It doesn't matter.

Then remember to always shut the gas off when your done riding. Use On/Reserve as you normally would and You'll never use Prime, it would essentially be just like off.

If you do a search on removing the special octopus your doing almost the same thing, just you didn't have an octi to start with.

[psycoreefer]

Oh, and your vent hose, the upper hose from each pair of carbs. Make sure you don't plug it off, assuming you don't have a stock air box just put a little breather filter on the end of it and route it someplace out of the way. If you do have a stock airbox, hook them up where there supposed to be.

[lostsoul74]

thanks, got her all set. much appreciated, she runs fine, in any position, but doesnt leak. Admin, please go ahead and close/delete this post, as i've cleaned her all up ready for pics and want to create a seperate thread about hte bike in general. (dont want to spam the postings)

[badbrown]

That bike looks great. Only thing is you should do a molded seat instead of the solo. That's a nice seat but its a tad out of place. Do one flat to the frame for a more finished look IMO. nice job though.

[lostsoul74]

I'm 50/50 on the seat, it looked good with the standard tank on it, gave it a streetfighter look, i still like it with the special tank, it follows the contours well. definately dont want a big double seat like what was on it, i threw that thing out. but i do have a wide altima seat that i've put on there before, it's 14x14 where as this one is 9x13. the wife says she likes the wider one better, but i'm still undecided. i get more of a crotch rocket feel with that seat, expecially with my knees in without forward controls (for now), and i'm a bit of a wild rider who rides it like a rocket. live fast