1. Hello Guest. You have limited privileges and you can't "SEARCH" the forums. Please "Log In" or "Sign Up" for additional functionality. Click HERE to proceed.

82' 750 Resurrection

Discussion in 'XJ Technical Chat' started by Brandon Spencer, Oct 8, 2019.

  1. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

    Messages:
    19,613
    Likes Received:
    6,703
    Trophy Points:
    113
    Location:
    The City of Seven Hills
    Idle speed is 1,100 RPM (minimum), but they tend to idle better closer to 1,500 RPM (which also makes cold starts easier). Set idle speed when she's fully warmed. You may need to adjust it a tad during a ride, but don't lower it too much or you'll have it set too low when cold.
     
    Brandon Spencer and hogfiddles like this.
  2. Brandon Spencer

    Brandon Spencer Member

    Messages:
    98
    Likes Received:
    50
    Trophy Points:
    18
    Location:
    Delaware
    Been a few days since an update, was waiting on my Colortune and worked on my exhaust...also got a new toy...

    Bike was pretty loud and I figured it may be time to re-pack the mufflers...turns out there was no packing left which then made sense.

    Ordered 2 "MuffPack's" off eBay which includes steel mesh, steel wool and fiberglass layers.

    20200808_182936.jpg

    Pretty straight forward to perform the repacking. This bike came with aftermarket slip on's which are Cobra F1R's.

    Removed each side from the collector and separated at the clamp. Tapped out the baffle with a wooden dowel, these were pretty rusted in there (little heat helps).

    20200731_121757.jpg 20200731_121809.jpg

    There was some left over packing on one of the baffles (like one fiberglass chunk), that was it....cleaned them up on the wire wheel and removed rust present on the inside of the muffler where the baffle sits.

    Onto the packing. First was the steel mesh wrap, followed by the steel wool. This was then bound together with provided metal wire. Final step was adding the fiberglass. Layers of steel wool and fiberglass needed to be trimmed to fit the length of the baffle and leave enough space for the baffle taper to fit.

    20200808_183600.jpg 20200808_183927.jpg

    Everything was pushed back into the muffler carefully and aligned/tapped back into place. Back on the bike they went and WOW what a difference! Just by the sound in the garage it cut the noise down by almost half.

    Now it doesn't sound like I am crazy revving it up even when it's just at idol.

    Alright, onto Colortune and another round of carb syncing. All carbs set to 2.5 turns out and were tested. At idol all are burning that nice Bunsen blue. Blipped the throttle and saw it flashed yellow and a gradual increase remained blue.

    Given first time doing that I believe that is all correct...left all of them at ~2.5 turns out.

    Back to carb syncing, I dialed in each gauge on one cylinder first to make sure they were all reading the same. Hooked all 4 up and 1 and 4 where off a little. So synced 1 and 2, 3 and 4 and then 2 to 3. All 4 are now pulling same vacuum at idol and when revving up to above 2k.

    Took her out for a spin and I think I still need to adjust my idol speed a little higher, she bogs down until you give a good amount of throttle. Response at 1500k is wayyyy better and she just want to go. I'll mess with it more this week and keep riding around.


    New toy added to the garage this past weekend as my buddy and I finally got our lift! Harbor Freight 1000 lb lift with the Pittsburgh wheel chock mod. Wish I had this thing a while ago.

    (On the bench is the XV750 Virago engine which has compression and electrical issues. Need to buy a used front cylinder head unfortunately, bolt snapped off and we have been unable to remove it. Ebay it is! )

    20200810_112851.jpg 20200808_161858.jpg
     
  3. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

    Messages:
    14,626
    Likes Received:
    5,008
    Trophy Points:
    113
    Location:
    near utica, new york
    And after you do that, then you can do the starter repair.........the first time of many———
     
  4. Brandon Spencer

    Brandon Spencer Member

    Messages:
    98
    Likes Received:
    50
    Trophy Points:
    18
    Location:
    Delaware
    Yes the XV is a Box O Rocks for sure. Even though its the "newer" gen starter
     
  5. Brandon Spencer

    Brandon Spencer Member

    Messages:
    98
    Likes Received:
    50
    Trophy Points:
    18
    Location:
    Delaware
    Well, solved my issue getting her tuned in....

    Broken spark plug...I have no idea how but during another colortune session cyl No.3 ran a whole lot better with the colortune plug in it. Looking at the spark plug I noticed powder falling from the insulator and then it literally separated from the bottom part of the plug..

    20200817_145818.jpg

    So there's that. New plugs all around and I will keep the other ones as spares. I take it cyl No.3 was running intermittently since it couldn't produce constant spark.

    Dialed in the tune to have the mixture screws to 2.25 turns out. After riding around I think I will lean them in a 1/4 more since idle wants to rise up still (even after adjusting during ride).

    My choke actually works properly now on a cold start and when warm causes idle to rise vs bogging it down.

    Only able to cruise around at about 30 mph (in neighborhood) but good throttle response and in 3rd gear I can quiet her down a bit to just about 1k RPM.

    Added a new key chain because why not. Pretty proud of this build as it's my first and have more plans ahead!

    20200817_161230.jpg
     
  6. hogfiddles

    hogfiddles XJ-Wizard, Host-Central NY Carb Clinic Moderator Premium Member

    Messages:
    14,626
    Likes Received:
    5,008
    Trophy Points:
    113
    Location:
    near utica, new york
    I would not adjust them leaner. It may take awhile of fine tuning the idle speed. As it get warmer outside, it may tend to raise the idle, so back it off in ever tiny amounts til you’re happy. As colder weather approaches you may have to ever so minutely bump it up a bit. I keep mine right where it idles how I want it in the 75-85 temp range if it real hot it may go up a bit, in cold weather as it drops lower than I like — I just keep a very slight load on the throttle.

    Sounds like you’re getting sorted though!!
     
    Brandon Spencer likes this.
  7. Polock

    Polock Well-Known Member

    Messages:
    9,751
    Likes Received:
    2,093
    Trophy Points:
    113
    Location:
    Beaver Falls, PA
    i concern myself with the idle speed for exactly how long the red light lasts
     
  8. Brandon Spencer

    Brandon Spencer Member

    Messages:
    98
    Likes Received:
    50
    Trophy Points:
    18
    Location:
    Delaware
    Been a while since I've posted but here is a video link to taking her out for a short ride!



    Trying to figure out my cheap speedo's gas gauge. Settings are either 2 wires or 3 wires, which this bike only has 2. On setting 2 it reads nothing, but with 3 it reads half tank when empty. So added 2 gallons and it shows roughly 3/4 full.

    A little annoying since now half tank is technically empty and I am not sure if adding resistors would help. Reading 145 ohms with 2 gal in, which is accurate. Thoughts?

    Eventually going to swap this one out for a Acewell but would like to get this one more accurate for now.
     
  9. Polock

    Polock Well-Known Member

    Messages:
    9,751
    Likes Received:
    2,093
    Trophy Points:
    113
    Location:
    Beaver Falls, PA
    maybe add your own ground wire then flip flop wires
     
  10. Brandon Spencer

    Brandon Spencer Member

    Messages:
    98
    Likes Received:
    50
    Trophy Points:
    18
    Location:
    Delaware
    Ok figured it out with some trial and error using resistors.

    By setting the speedometer fuel sensor setting to "2" on this particular unit and adding a 120 ohm resistor I was able to finally get proper fuel level readings. Added about 2 gallons and got half tank reading, emptied tank until reserve is needed which leaves 1 bar. If the gauge starts flashing it means your reserve is low.

    I take it this gauge reads a lower ohm threshold than the stock 25-300 ohm unit sends.

    20200917_190453.jpg
    20200917_191557.jpg

    In addition poking around on some more info on this gauge, even though I have it set for a 4 cyl engine, the reading can be off. Switching it back to 2 cyl my RPM's read much better and actually it was off by about 500.

    So now my warm idle reads about 1200 RPM where before it was reading under 1K and I kept bumping it up to get to the 1100-1500 range where it really was sitting close to 2k (LOUD).

    Working on my buddies helmet cam set up but I will get another ride posted to where you can actually hear the engine without wind noise.
     
  11. Timbox

    Timbox Well-Known Member

    Messages:
    2,278
    Likes Received:
    748
    Trophy Points:
    113
    Location:
    Wisconsin, Tomah
    Thanks for the ohm resister information, I am doing the same thing to a Seca. I guess I can do that as well, but I was going to just use the trip mileage gauge. As far as the RPM's going , that gauge looks to be the same as mine, off Amazon. It is not very responsive and I do not think it is very accurate. Again, thanks for the great info and good luck with the rest of your project.
     
    Brandon Spencer likes this.
  12. Brandon Spencer

    Brandon Spencer Member

    Messages:
    98
    Likes Received:
    50
    Trophy Points:
    18
    Location:
    Delaware
    Try setting menu 3 back to 2. It's actually the number of coils not cylinders as I found in my research. My tac is pretty responsive and with what my idol is set to now the bike runs very well. Still dialing in the tire circumference setting as my speed jumps all over the place and so far it has not been able to read over say 45mph.. Circumference of the 100/90-19 tire is 2081.62, I just reset it to this number and need to go for a ride. True tuning will be with a GPS for speed and adjusting up or down.
     
  13. Polock

    Polock Well-Known Member

    Messages:
    9,751
    Likes Received:
    2,093
    Trophy Points:
    113
    Location:
    Beaver Falls, PA
    the magnet has to pass over either end of the pickup, not the middle. the closer the better, i'd say 5mm max
     
  14. Timbox

    Timbox Well-Known Member

    Messages:
    2,278
    Likes Received:
    748
    Trophy Points:
    113
    Location:
    Wisconsin, Tomah
    For the speedo I did the mark the tire and floor measurement. Mark the side of the tire and mark the floor, roll the bike until the tire makes one full turn. Measure that distance, change it to metric and put that in the speedo. Worked great for my BMW project, it was right on.

    I will swap that over to the coil number instead and see if that makes the change. Thanks for the info.
     
  15. Simmy

    Simmy Well-Known Member

    Messages:
    2,261
    Likes Received:
    1,126
    Trophy Points:
    113
    Location:
    Waterloo Ontario Canada
    I have a magnet triggered speedo on my KTM. Best way is to put a dollop of mustard on the tire and roll the bike through a revolution.
    Then measure the distance between the mustard spots. Ketchup looks too much like another grease spot, yellow mustard is best LOL!
     
    chacal, Brandon Spencer and Polock like this.
  16. 50gary

    50gary Active Member

    Messages:
    343
    Likes Received:
    128
    Trophy Points:
    43
    Location:
    Saginaw, Mi. USA
    Nice flag.
    Cheers, 50gary
     
    Brandon Spencer likes this.
  17. Brandon Spencer

    Brandon Spencer Member

    Messages:
    98
    Likes Received:
    50
    Trophy Points:
    18
    Location:
    Delaware
    Hey guys! Been a while since I've posted but here is a first ride video of this build!

    She's a little boggy on the low end in 1st gear, my sync is not perfect and waiting on a YICS tool to come in for assistance with that. Overall she ran great!

     
  18. Rooster53

    Rooster53 Well-Known Member Premium Member

    Messages:
    1,852
    Likes Received:
    723
    Trophy Points:
    113
    Location:
    North, FL
    Hey you didn't tell us it was "R" rated - stupid bridge :)
     
    Brandon Spencer likes this.
  19. Yammaat

    Yammaat Active Member

    Messages:
    213
    Likes Received:
    55
    Trophy Points:
    28
    Location:
    Netherlands
    Only straight roads??
     
  20. Brandon Spencer

    Brandon Spencer Member

    Messages:
    98
    Likes Received:
    50
    Trophy Points:
    18
    Location:
    Delaware
    Warmer weather is upon us!

    Took the bike out a few times and back on the lift for further work. First was oil change and now onto final phases.

    Tires need to go along with what I assume are the stock bearings...fully stripped the wheels as they will be going for sandblasting and powder coating.

    Bearing puller made easy work as well as a tire changing kit.

    IMG_0471.jpg IMG_0472.jpg IMG_0473.jpg IMG_0474.jpg IMG_0475.jpg IMG_0476.jpg

    New Dunlop 404 tires from 2Wheel.com. Got them to me the next day.

    (Virago 750 motor was rebuilt over the winter, fixed compression issue in front cyl and she now runs. That bike is going to be a large project which I will eventually make a new post about.)

    IMG_0477.jpg

    New wheel bearing kit for front and rear which I'll install after power coating.

    IMG_0478.jpg IMG_0479.jpg

    Among my list of to-do's is strip and paint my front fender to match new paint color and replace the OEM shocks.

    IMG_0480.jpg IMG_0481.jpg

    Also need to order a new front MC (TC Bros) due to the cheap one I originally got does not handle dual brakes really well. I've bleed the brakes at least 5 times and can never get firm pressure. Overnight zip tie method didn't help much. Brakes do work but not where they should be.

    Looking forward to riding in warm weather for once!
     
    k-moe likes this.

Share This Page