1981-1983 Yamaha Virago Carb Rejetting (Includes Test Runs)

Поділитися
Вставка
  • Опубліковано 26 гру 2024

КОМЕНТАРІ • 39

  • @StilwellMotovlogger
    @StilwellMotovlogger 10 місяців тому

    Bought a 82’ virago 920 a little over a month ago. Had been sitting for 12 years. You have the best and most informative videos I’ve come across on these bikes. And because of that I’ll get to take it out for it’s first spin tomorrow

    • @StevesDIYs
      @StevesDIYs  10 місяців тому

      Thanks ! That’s great to hear that the videos helped some to get it back on the road 👍. 12 years is quite a while so I’ll be it took a bit of work for sure. Thanks again and all the best ! Steve

  • @seniorrider9337
    @seniorrider9337 3 роки тому +1

    Steve, Your air cleaners look so nice, I wanted to get rid of my "bug eyes" on my 97 1100. I removed the stock air cleaner, man is that thing restrictive. Inside the air cleaner is a about 1"X 1 and 1/4 " passage where all the air must flow thru. Anyway, I put on a 4" round by 2" thick air cleaner that fits in the place where the stock air cleaner was. The square inches of air cleaner stock is about 26 sq. in. The 4' by 2' round filter gives me about 25 sq. in. Since I put it to replace the stock filter, both carbs pull air thru the one filter and the frame. It runs well and I am presently running a gas mileage test run to check the mileage. Plugs are running great. I did this after having to remove my carbs and rebuild them due to running very rich after being stored for the winter. I found a white corrosion in the float valve cavity and on the o-rings. Thanks for your carb rebuild videos and sync videos, they were a big help. Wish I could post a video showing the installation of the air cleaner and the new air filters I put on the carb vent tubes. Checking the float levels with a gas set up is critical to get the correct float levels in each carb. I set them both with my calipers and still had to adjust one of them to get the fluid level in the clear line at the correct level. I final synced with a single vacuum gauge, going back and forth until they were even and running sweet. Took it for a run after warm up, not a spit or sputter, just pulling from 1500 RPMS like a tractor! Thanks again for all of your videos on Viragos.

    • @StevesDIYs
      @StevesDIYs  3 роки тому

      Thanks man ! Glad the videos have been some help along the way 👍. Yep, over the years I’ve found that once everything is all setup and adjusted right, these old bikes run really well and aren’t bad to maintain (I start mine once a week and let them idle a bit even in the off season to keep fresh fuel in the carbs...I also run non-ethanol fuel since I don’t think ethanol in the fuel was very common back in the ‘80’s). For sure, Yamaha has a very restrictive air intake on all of these it seems. When I switched out to the separate air filters, it would idle, but that was about it, lol. I ended up blocking off and tuning the air opening to get it to where it would pull hard again as there just wasn’t a way to balance the massive amount of air with enough fuel and have a steady acceleration. Thanks again for the compliment and all the best ! Steve

  • @BIGGZ46
    @BIGGZ46 Рік тому +1

    Hey Steve, another great video. I finally got the virago running. Cleaned and rejetted the carbs and perfected float height all thanks to your videos. Question, at 1/8 turn of the throttle the bike pulls , but anything more it starts sputtering, but fortunately no back firing. It doesn’t pull hard at all, almost like a clogged fuel filter. It’s an XV920 I have 140s and 50s for the jets with one shim under the needle. Does this behavior indicate I’m too lean or too rich? Thank you

    • @StevesDIYs
      @StevesDIYs  Рік тому +1

      Hey man, that’s great to hear…congrats as these can be tough to get going again sometimes 👍. For the dead throttle, it sounds like it’s getting too much air for the amount of fuel. An easy way to tell if it’s too much air is to restrict some of the air coming into the carbs to see if it allows it to rev in up. For a quick check, I just put my hand over the carb with my fingers opened up with gaps in between so it’s not restricted, then try to rev it up and slowly close my fingers together to see if it revs on up. If it will rev up, then there’s too much air for the amount of fuel the jets are providing. If you are now running separate air pods, you’ll probably have to block off some of the air flow as these allow way too much air in for the system and the slides won’t lift up without some restricted air very well. An opened up exhaust also changes the air balance, but that can typically be compensated for with bigger jetting or restricting some air flow as well. Hope this helps a bit and all the best ! Steve

  • @mcrand7887
    @mcrand7887 Рік тому +1

    Hi Steve, what are those air filter pods name? Won't rain water penetrate and get sucked in carburetor?

    • @StevesDIYs
      @StevesDIYs  Рік тому +1

      Hello, they are the intakes from a Volkswagen Karmann Ghia. They are the foam filter type and actually allow so much air in that I had to put thin aluminum blocking strips covering about 3/4 of the filter surface to get the motor to tune properly (even with bigger jets). I blocked the fronts of the pods off so the air can only come in at the rear…that way rain water doesn’t get pulled in 👍.

  • @zackgoolsby2444
    @zackgoolsby2444 3 місяці тому +1

    Where you get those bags. I can’t find bags for my bobber anywhere

    • @StevesDIYs
      @StevesDIYs  3 місяці тому

      Hey man ! The ones I put on are called Swing arm bags vs. side bags I believe. I didn’t mount them in the swing arm though…I added a piece of aluminum (from an old road sign lol) inside and bolted them to the frame so my battery is in one and all of the wiring is in the other.

  • @MarkGrinevich
    @MarkGrinevich 10 місяців тому +1

    Hi Steve! Thank you so much for your videos. You helped alot!
    I have some questions.
    1.
    I have an 83 Midnight Virago. My main jets are both 122. Should I put something biggger for the rear?
    2.
    The old emulsion tubes got destroyed by the previous owners. I ordered used OEM (good condition) I can't figure out which one go where. 1 tube has 3 holes, the other has 4 holes. Which one goes where?
    3.
    1 carb has a wrong pilot air jet inside. Book says it needs to be 185, I have a 180 sitting in there.
    Will that cause concern?
    Thank you VERY much! 😊

    • @StevesDIYs
      @StevesDIYs  10 місяців тому

      Thanks and glad the videos have helped some 👍. I’ve had several over the years that have 122 jets on both front and back from the factory and they do fine with stock air filters and stock exhaust…seems Yamaha played a bit with different jets and some had both 122 size while others had a 122 and a 123.
      For the emulsion tubes, it seems the 4 hole ones have always been for the rear cylinder, but there again, one of mine only has 3 hole levels for both and I was the first to ever take it apart. I don’t think it makes a huge difference from what I’ve seen.
      For the air jets up top, I’ve only seen 50 for the main and 185 for the pilot, but since the mix needle is adjustable it might be fine with a 180 jet. If it wants to stumble when coming off the idle circuit to the acceleration main jet circuit, stepping up to the 185 may help a bit since you can adjust the mix needle out for more fuel.
      Hope this helps a bit and all the best ! Steve

    • @MarkGrinevich
      @MarkGrinevich 10 місяців тому +1

      @StevesDIYs thank you so much, the parts finally came in. I'll be putting the carbs back together soon.
      The bike kept running rich on one of the cylinders. The float level is ok, I'm suspecting it was the emulsion tubes because they were destroyed with a screw driver, and there wasn't a proper seal with the needle.
      After I rebuild the carbs and the cylinder still runs rich, what's something I can check next on these 1st gen xv750s?
      Can it be coils or valve adjustments?
      It does have a ticking sound when it warms up.

    • @StevesDIYs
      @StevesDIYs  10 місяців тому

      @@MarkGrinevich hey again ! If, after setting up the carbs with the new parts, it still is running rich on a cylinder, I’d check to be sure you have good compression on that one compared to the other. That might indicate that a valve is not seating (gap or just dirty) or that the head gasket or rings may be bad. If the compression is low, the fuel won’t completely burn and it will foul the plug.
      You mentioned a tapping noise once warm…sometimes that’s the cams, but it can also make the same tapping sound if the head gasket are bypassing I’ve found (there’s actually a video on the channel under the 1st Gen playlist where I ran into that a few years ago. Checking the compression when cold, and then again when warmed up should help to determine if the head gasket has gone bad.
      Hope this helps a bit and let me know how it goes 👍. All the best !

    • @MarkGrinevich
      @MarkGrinevich 10 місяців тому

      @StevesDIYs I'll definitely check it all out. Currently, the compression sits at 100 PSI on both. That's with the carburetors completely removed in a cold garage. I'm also at a high altitude of 5,300 ft.

  • @specialse
    @specialse 4 роки тому +1

    Very interesting , just found your videos , ive had a stock first gen 750se and rigid frame chopper with first gen motor since .......1989 !! stock bike has always had noisy starter , ive tried every possible cure suggested ( and there has been a few ) at last some one who understands the machine and how it works..the modern endoscope fitment has opened up a hole new world ..im going to carry out your mods to the letter ( i have my own lathe etc ) and many spares. my question is this , do Hitachi carburettor jets have a different thread size to others ? ie Mikuni Keihin etc ? im still on standard jets but from a TR1 1000 and......on the chopper ive been running 1970,s mini copper S pancake air filters restricted in the same fashion as yours ... but with the opening to the front ( its never run right ) i never thought about just turning them round !! :-/

    • @StevesDIYs
      @StevesDIYs  4 роки тому

      Hey man ! That’s cool that you’ve had Gen 1’s since they were only a few years old 👍. I got my stock ‘81 xv750 a long time ago as well and it was the only bike I had from my 20’s that survived the abuse from my younger years, lol. The bobber and the other two Gen 1’s I’m planning to build back into bikes this winter are more recent additions to my apparent addiction 🤣. For the jet question, I think each carb manufacturer has a slightly different style on the threads. I went to a web site called “Jets R Us” to get mine for the bobber...seems like they have Jets for most carb makes and nice little pictures so they can be compared. Yep, when I first built the bobber and put the individual air filters on I couldn’t even get the rpms about about 2000. The restricter plates I made were just on the outside so when I went down the road it would ram air into the carbs and lean them out so bad it was like hitting a rev limiter. Once I put them on the inside and outside of the filter to create the more laminar air flow it took right off...then just had to play with the opening size to be restricted enough to allow the revs to go up, but still give the nice torque on the low rpms. All the best ! Steve

    • @specialse
      @specialse 4 роки тому +1

      @@StevesDIYs yup had exactly the same prob years ago , and actually rode it like that for a long time , it wasnt until reading BSH (back street heros ) UK chopper mag that i found out about restricting the air flow . it was like the clouds opening and the sun shine through the day it reved out fairly clean ...i couldnt have been more happy .And all those years ago VERY pre internet i flew to the US with my brother and bought a fire damaged XV and shipped it home myself !!!! it was the only way back then . the mass container loads of ex USA bikes hadnt starting arriving yet , that didnt happen till years later .But even then the XV was a rare bike. im glad i collected all the stuff back than as i couldnt afford it now ,,,apparently they are classic bikes !!

  • @nucl900430
    @nucl900430 4 роки тому +1

    Which sizes will you try later?
    125 and 43?

    • @StevesDIYs
      @StevesDIYs  4 роки тому +1

      Hey man ! It’s doing pretty good with the 128 and 43 so I’ve left it like this for the season. I may try a 125 on the main and leave the 43 pilot to see if I can get rid of the slight backfire I get, but so far it’s riding good with the 128. All the best ! Steve

  • @JimmyShagoury
    @JimmyShagoury 4 роки тому +1

    I have a 82 xv750 bobber project, I just pulled the carbs for a rebuild. It looks like I’m gonna be running this same jet sizing thanks for the video! Do you not recommend the rear cylinder to be larger jet? That’s what the book says to do but I couldn’t find much info on it.

    • @StevesDIYs
      @StevesDIYs  4 роки тому +2

      Thanks man...glad the video helped some 👍. For the bobber (‘82 xv750 ), it had the same sized jets originally, but has different emulsion tubes for the front and rear (one has more holes). My manual shows two different sized jets as well and they are different for my ‘81 xv750, but the emulsion tubes are the same so I think they must have made a few changes along the way for the Gen 1’s. Once you open them up (if you haven’t already), you might check to see if the emulsion tubes are the same or if the jets are the same. They may have even put different jets and different tubes in some (hard to get solid info after so many years). If yours are different, the back one may need to go up a number when rejetting 👍. All the best ! Steve

    • @JimmyShagoury
      @JimmyShagoury 4 роки тому +1

      @@StevesDIYs ok awesome! I haven’t gone into them yet so I will definitely check it out and see what the deal is with this set and go from there. Im also going to probably be doing the bendix clip clamp for the starter on this bad boy too. Thanks so much!

    • @JimmyShagoury
      @JimmyShagoury 4 роки тому

      @Steve’s DIYs Hey steve, I’m going to need to order some main and pilot air jets, the ones under the choke tube, and I can’t find them anywhere, any idea where I can get them? Everywhere I look just has the main and pilot jets themselves but these have a smaller head. Thanks

    • @StevesDIYs
      @StevesDIYs  4 роки тому

      Hey man, for some reason UA-cam is not letting multiple comments post....I saw you had posted an additional comment, but it went away and is not longer visible. If it was a question you can email me at stevesdiys@gmail.com. All the best, Steve

    • @StevesDIYs
      @StevesDIYs  4 роки тому

      @@JimmyShagoury , hey man ! Sorry for the delay in replying...looks like UA-cam got the comments working again 👍. Yep, I’ve never been able to find the upper jets under the choke crossover tube anywhere either unfortunately. I thought about making a few if folks needed some so I may do that. I’ll let you know if I make some if you haven’t been able to find any by then. All the best ! Steve

  • @wiilybadboy8954
    @wiilybadboy8954 Рік тому

    I think your fuel filters are in the wrong direction there is an arrow in the direction of flow

  • @williamhart2344
    @williamhart2344 4 роки тому +1

    Hey Steve! I have a first gen, stock XV750. I just rebuilt the carbs and bench synched them up. The bike will start but idles very slow and almost dies out without some throttle. This happens even with the idle screw maxed out. However, it sounds great cruising around in 1st gear. I have the pilot jets turned 2 times from a soft seat like you suggested. I'm going to adjust them one cylinder at a time tomorrow as you explained and hopefully achieve optimal rpm. Do you think that's most likely the fix for the problem or could there be something else going on?

    • @StevesDIYs
      @StevesDIYs  4 роки тому

      William Hart , hey man ! I would definitely start with the idle mix needles to see if turning them in or out a little more will bring the rpms up. Either too rich or too lean on the idle will cause the rpms to be lower. You’ll hear the motor pick up on the idle rpms (and smoothness) when you get the idle mix needle dialed in. The exact amount of turns (and partial turns) varies from carb to carb so each carb should be slightly different. Once I get them close so it’s idling and pulling good, I run it around for a week or so and then tweak them again till they are stable. For example, after a couple of weeks after doing the video, I ended up turning the rear cylinder carb needle out another 1/8 turn as I was getting a slight pop coming from the pod until the engine warmed up indicating I was just a tad lean. I’ll bet you’ll have it dialed in in no time 👍. Let me know how it goes, Steve

    • @williamhart2344
      @williamhart2344 4 роки тому

      @@StevesDIYs Hi Steve, I think there may be an issue with the linkage between my two carbs. I've noticed there is a decently sized dead zone of responsiveness with the left carb. When I open the throttle, the right side will move immediately and the left takes quite a bit more of a turn to start opening up. A forum I read referred to this as "slop" and said its from age and wear. What's your recommendation for fixing this?

    • @StevesDIYs
      @StevesDIYs  4 роки тому

      @@williamhart2344 , hey man ! Yep they do wear over the years in the linkage, but the bench sync usually takes most of that out (as long as all of the linkage components are all there (the slide roller, the screw spring, link washers, etc). There’s a video on the channel for how the link goes together were I rebuilt some carbs. If you lift the right side arm where the throttle cable connects, it should immediately lift the left side arm if the linkage screw is set right from the bench sync...even with a lot of wear in the linkage. The link screw is set so that it takes the looseness out when the carbs open up. As long as the center linkage adjustment screw is not fully bottomed out it should be able to be adjusted to get them to lift at the same time. The looseness is then only for when the arms are lowered, but that is accommodated by having the idle stop positions on the arms (the one in the right with the knob used to raise/lower the idle and also the one on the left that keeps the left carb from closing completely due to the linkage looseness. If you’ve watched the bench sync video on the channel, you start buy setting the gap on the right carb with the idle adjustment knob (I used a piece of paper), then when you switch to the left carb, you have to first back the small screw down that holds the left carbs arm up before getting the gap the same by adjusting the center link. Once it’s set, you then adjust the small left arm’s screw up to get a base position for the idle on the left carb. If your center link is maxed out on the adjustment, the linkage is probably too worn though to get them to sync, but if it’s not bottomed out, they should still sync up. Sorry for the very long reply, but hope it helps some, Steve

    • @williamhart2344
      @williamhart2344 4 роки тому +1

      @@StevesDIYs I think I finally, got the synching of the butterfly valve understood. However, I was still not able to get the rear cylinder to idle without full choke. I removed the pilot screw and noticed that the needle tip is bent slightly off to one side. I assume this happen from it being seated too far/hard. Could the tiny bend in the needle be the cause of my problems?

    • @StevesDIYs
      @StevesDIYs  4 роки тому

      @@williamhart2344 , hey man. Yep, for sure a bend in the tip of the mix needle will throw the amount of fuel that is pulled up. Also, if you pull both of them and compare the tip lengths, they should be identical. If the bent one is shorter the end of the thin tip may actually be broken off in the hole in the carb body as well. You would have to get a thin wire and push it back out. If they are still the same length, but the one is just bent, you could try to carefully straighten it and see if it improves the fuel amount. If it does improve, but still isn’t exactly right after adjusting, it might need a new needle. The adjustment is very sensitive on these needles...just a quarter turn of the thread will go from good to too rich or too lean.

  • @doktormoney
    @doktormoney 4 роки тому +1

    Nevermind, found it. Haha

    • @StevesDIYs
      @StevesDIYs  4 роки тому +1

      Hey man ! Yep, you found the video I was gonna send a link to 👍. It does change the air / fuel quite a bit to open the air flow up for sure. All the best ! Steve.