I visited the other site, but couldn't find the answer for this question.
Outline, I have one of these bikes in the shop right now, lean on the needle, so I will shim them up. It is a 1982 XV920.

But, there are two different needles in this set of carbs, one is identified with a Y-24, the other is Y-25.

Which one is for which carb? I would think the rig=cher one would be for the rear carb, leaner for the front, to help cool the rear cylinder. I called my favorite parts person in Carson City, and we went through all years of Vertigo's, but the parts info says all had the same needle, not different for front and rear. These two needles are about a millimeter difference in length from each other.

Which one is the richer one, which one goes in what carb???

Any ideas??

This is a common question.

Each carb has it own parts. Even some have different number of holes in the emulsion tube for the main jet. Always best to keep parts seprate.

But yea the rear cylinder should be richer but some run it backwards n say it runs fine. but logic says no.

What kind of carbs?

Do they have the pressed in pilot jet tubes or does
it have a normal removable pilot jet?



Virago's came factory set real lean and all the mags back then figure out you need to drill the stock pilot jet to a .50 #76 drill bit size to fix the problems.

Also the MVC mixture control valve hooked into vacuum lines is a bugger part. If it can be removed do so. Almost always cured the pop n decel problems.


But myself my bike was never better till after I did the pilot jet mod. Even with a stage 1 jet kit that mod made the most difference. I also have the bigger needle and jet in rear cylinder.


Only folks who need to shim the needles are ones with pressed in brass pilot jet tubes as ya can't bore them out easy.


Orings on the pilot jet screw also get bad n leak easy. Folks tend to bugger the tips to when they seat them to hard.

Other typical problem is pin holes in vacuum control petcocks and gas flows right into engine via the vacumm lines making it run rich.


Allot of the 750 info is the same as 920, so Ill just list a bunch of junk to browse through.



http://viragotech.com/improvingthevirago.html

http://viragotech.com/vitalizingthevirago.html


http://viragotech.com/XV750/750viragotechinfo.html

http://viragotech.com/XV920/920viragotechinfo.html

http://viragotech.com/phpBB/viewtopic.php?t=2082

http://viragotech.com/phpBB/viewtopic.php?t=6906

http://viragotech.com/phpBB/viewforum.php?f=75

Ok by the book the 920 has a #126 rear cylinder main jet, and a #124 front cylinder jet and the needle is a Y22 for both


The 750 has both #122 main jets but a Y23 in the rear and a Y22 in the front.

someone was playing with out knowing much I bet.
shimin the needle or going larger isn't the problem with the stock carbs it the to small pilot jet.


also could be 1000-1100 carbs or????
Not sure on their specs I can look it up.

Folks tend to just buy used carbs when they can't do them their self. Which isn't a good idea.

We got a guy making a single carb intakes for like $85 just a FYI

This thing is a 20,000 mile dead stocker, carbs are from the original bike. I could see where some dealer would want to change thigns if a customer complained.

I already went up on the pilots, idles nice, is OK off idle to 2,500, then falls flat on its face. I raised both needles the equivalent of one clip distance. Just took the needles out and thought these were both the same, not staggered.

I'll try the 24 in the front carb, the 25 in the rear, with shimming, and see what happens. Once you get the sequence down, taking the carbs on and off isn't that big a deal.

Thanks, Matthew.

check the vent tubs for the top of the carbs. The big hoses run down the frame, they got kinda of filter in the line and bugs lile to make homes in there. Screwing things up.

That the biggest problem. dealer don't know squat how to fix or tune a Virago right.

I never suggest anyone take their Virago to a dealer, gotta do your own work.

They just have their own quirks that you must open a book and read. Dealers think they know everything and some wont even touch a Virago as they can't tune them right.

Well it not the bike but them. Which is why so many of us get real low miles ones for cheap.

Only thing I did with the dealer was check what needles should be where, and their parts fiche said both needles should be the same.

I am aware of the vent and emissions stuff and how lean they were back then to comply, but lately, I have seen some really lean stuff here, and we are 4,400 feet altitude.

This bike is very clean, very nice, no regular disasters you find usually, just lean city. I guessed at the drill size for the pilots, from experience, and hit your number drill above. I replaced the O-rings on the fuel screws already. I do a LOT of carbs for people that had them done some place else, and wrong, and for people that just parked their bikes years ago, because nobody could get them running right.

I repair stuff that comes from dealers all the time. They let it fly, I fix it. The largest dealer in Carson City recommends me for their bikes 2000 and earlier, and they just gell the customers to get in touch with me, and leave it, I'll get it dialed correctly. Usually, I have to redo all the idiot stuff others have done previously to "fix a problem" that isn't the real cause of the problem, then, diagnose the real trouble, and fix it.

I just had a DR350 leave that was in 7 shops in this area over the last 4 years, never did run good. I had to adjust the valves nobody did before, reset the float level off the bowl floor that someone tried to fix a fuel leak with, was corroded needle seat, then, it ran poorly. It decided to die completely just down the street, no spark. So, I checked resistance in the stator and magnetic pickup, pickup was open. I pulled the side cover off, and found one pickup wire out of its holder, and strands broken inside the wire. I fixed it, and it ran a lot better, then, it just wouldn't start easily, so, I checked the resistance cap for the plug, died as well, so...a $5.00 new spark plug cap, and it runs like a top. Just goes to show, diagnosing problems are sometimes harder when others think they are fixing the real problem with wrong settings.

Anyway, I'll go put the carbs back on and it should be OK on both the pilots and needles.

So your doing bikes and stuff now?

Whats your contact info for that. We always got folks from all over who don't feel comfy doing everything themselves.



Oh how are the intake boots? They crack bad n only suck when running sometimes. Squish n squeeze n man handle them around n see how bad they are cracked.

Mine only had/has less then 7000 but the intake manofilds were cracked bad. Didn't look like any of them went 100% through but coving the sucker in goop made it run better. First time I spent a while opening up each crack and filling with superglue. 2nd year all new cracks showed where it wasn't glued. So it got covered with seal-all till I got new ones.

Inlet manifolds are mint, no cracks, no warping, O-rings in great shape. I seal all of them anyway, always have, use Three-Bond 1104. I did so to a CX500 yesterday, the turd pile.

The new bike place is a take off on both me, and the bikes, pre-2000 Japanese bikes. THE OLD MOTORCYCLE MECHANIC. The hook is, only an old geezer can properly work on older bikes, because I worked on them when they were NEW, at the factories!

My neighbor's kid's FZR600 has leaky inlet manifolds, and NOHTING will seal them, because he put real silicone liquid on them, and they are done. New ones are a mere $104.90 EACH.

If you have a later model bike, and need an online parts pic, try these sites, they are both online dealers with parts fiche uploaded:

bikebandit.com
worldofpowersports.com

Nothing better than a parts exploded view in most cases. Bikebandit helped recently with a series of views of the engine for a 1959 CA95 Benly Touring 150cc bike I have in the shop right now, along with a new float for the carb, from my local dealer parts manager guy, same guy I asked about the needles (he's the younger guy that recommends all the older bikes to me).

Two weeks ago, this coming Sunday, I was at Willow Springs, near Rosamond, Ca. (Edwards AFB area), at an AHRMA vintage road race. An old Kawasaki Team rider my age, and a couple of new ones and I, raced old A1R's, an F9R, 3 H1R's, 4 H2R's, and a KR750, all Factory road racers from the 1960's and 1970's. I worked for Yvon DuHamel at Team Hansen and Team Kawasaki Road Racing for 4-1/2 years in the early 1970's.

The three street bikes I ride now are:
1980 KZ1300 6 that has been GPZ'd and hopped up
1985 hopped up RZ500 two stroke 4 cylinder, modified
1971 Bridgestone GTR 350 two stroke twin, certified, one of the last 10 ever made

What........you thought I was only a car mechanic??

Well, I found some nylon washers that raised the needles .020, one half a needle clip groove. That works good.

The #76 (.020 inch) sizing of the pilot....doesn't. So, tomorrow, I pull 'em again, and size the pilots down to .018. Stock 41 is .0164 inch.

sorrt off kileter here but it made me think of it so ILl share.

but I built a set of 750 carbs once for a guy using 920 slides n springs, with rest of 750 guts.

Ya know the rubber part stuck on top of slides?

Well I had notice the 920 was a tad shorter with a softer spring, where the 750 was a tad longer with a stiffer spring or something like that. Both were different.

Well The 750 slides I had, the rubbed were bad, So I used the 920 ones n spring, did piot jet mod n put rest of 750 guts back in. Dude was thrilled with results.

Only problem now is, erratic idle with too large pilots that cannot be corrected with fuel screw settings. .020 os just too big for this altitude (4,400 feet). I will modify pilots to take a 4-40 Allen set screw in their middles, drill my own passages at .018.

I ended up with a .017 hole in the pilot jets, now, rock steady idle speed at 1,000 rpms, no hesitation, just runs golden. Altitude here is 4,400 feet.

I tossed this together, would the info be correct?

same contact numbers?

http://viragotech.com/dray.jpg

Fax number has been nuked, Verizon couldn't make the phone lines work for faxes, put up just before Noah finished the Arc, won't handle it. Verizon, an equal opportunity useless predatory company.

I just want to stay regional, as I already have too much work to do, Reno and Northern California areas only.

Thank you very much for the effort and thought, though.

wouldn't you mean southern cal???

maybe my geography needs work?

It do! Gegagrafics is not my strong suit as well, but LAS VEGAS is somewhat aligned with So. Cal., (Los Angeles), RENO is aligned with No.Cal., (Sac-a-tamatos, Sam Francisa-deli Sandwich).

Already set one your way, new guy in SF who doesn't feel comfy doing his own work on his Virago.

Oh, no, not another Vertigo with issues. ONE is enough. In fact, one is a lot MORE than enough.

Wanna have a lot of fun, take the rear master cylinder off a Honda GL1500 6. So far, I am at the removal of the entire exhaust system, all the lower covers, heat shields, battery box and cylinder head guards, and I STILL can't get to the compression fitting for the inner brake hard line. I have half my shop filled with parts off this one pile of mule dung, and I am still not at the darned thing. The other line is easy, banjo fitting, but, there is a support bar in place on the frame, that blocks the master, and it is a WELDED IN part of the frame, when it should be a BOLT IN REMOVABLE ONE.

Leave it to Honda to engineer the thing to be a giant pile of CACA.