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First XS650 Build, What to Look For

Discussion in 'The Garage' started by SlowMaintenance, Oct 5, 2015.

  1. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Great! You're doing well.

    There's a phenomenon that's common with carburetors that experience high temperatures.

    For your next puzzle, do Google searches on:

    "Gasoline boiling point"
    "Reid vapor pressure"
    "Heat soak"
    "Evaporative emissions"

    And, tell us what you think...
     
  2. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    Good keywords! Sounds like it may be unavoidable given the heat it's likely to experience, as that heat will cause the gas to expand and flood onto the ground. Though those keywords did lead me to some good reads about workarounds and how shutting the gas off a quarter mile before you reach your destination can at times be helpful. It also made me feel grateful that I have an XS650 and not a Toyota supra with a supercharger as it's nothing but Supra forums that come up when you search for heat soak lol. Those guys must love it.

    The main learning though is that this is fairly normal, and I plan to not stress about it as my bike sits in a parking lot and not a pristine floor that I would be concerned about having gas on.

    Thanks!
     
    Last edited: May 23, 2017
    TwoManyXS1Bs likes this.
  3. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Yew betcha, SlowMaintenance. I'm on stoopidphone, can't write a book, but can show you the watering holes.

    While riding, even tho' the carbs are in the heat blast behind the engine, there's still enuff airflow to keep them from getting too hot. Plus, the greatest remover of heat from the carbs is the gasoline's "latent heat of vaporization". Vaporizing the fuel in the carb throat cools them.

    But, upon shutdown and parking, those cooling actions disappear. And the carbs now absorb heat from the adjacent +230°F engine...
     
  4. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    Makes total sense. Once this bike is out of my parents garage it will never be an issue, but I'm glad to know it's not a bad sign.

    On another front, I went in to get the timing squared away last night. Had to do some tweaking to get it to idle at 1,200. Some research also showed that next time I'm with the bike I should break out the multimeter to make sure I'm getting between 12.9 and 14.5 volts at the battery when the idle is at that range as I've heard voltage issues can cause a problem with that. Also, should probably toss in new plugs as my old ones were black last I checked them from the oversized pilot jet.

    That being said, I did get it down to that range and the timing light showed it was hitting right on the FIRE line with a nice twist of the throttle advancing it out to the ADVANCE mark just as it should. Thanks to Pamcopete for the PAMCO and the e-advancer which seem to be working beautifully. I even tested these with just a capacitor (to see if I could limp it home on one if needed) and same thing. Works just as it should.

    Enough with the good stuff though, gotta be something that still needs doing right? Of course there is. I discovered a nice leak from my left side breaker cover, pictured below. (See bottom of cover for oil residue)

    [​IMG]

    Some quick forum searching brought me to this thread, describing the same problem. http://www.xs650.com/threads/oil-leak-cam-cover.20857/

    Findings are that if the oil is IN the breaker cover, the camshaft oil seal is the culprit. Advice appears to be that I should pull the breaker cover off, take a scotchbrite pad to the cam end, and reapply the oil seal, ensuring it sits flush with the back of the breaker cover, flat side pointing AWAY from the engine.

    I can't remember if I saw the spring on the back of the oil seal, if not, that's an easy enough thing to fix. Just need to find where they sell them. If the spring is there though, I'll have to see what I can do with the reapplication. I'll also check whether or not the PO had used sealant on the install. Advice seems to be not to use it. If I remember correctly I couldn't even get this seal out when I was doing the initial disassembly, so I'm thinking there is sealant in there.

    Other thing is that I remember not being able to get the gasket AND the o ring behind the breaker cover and still make it seat right. I believe I just used the gasket. That wouldn't explain the oil inside the cover though.

    More work ahead, I'll let you know how it goes.
     
  5. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    Pulled the cam cover off to check the oring. Seems to be in tact.

    As for the cam bearings, I still have the photos from when I installed them and I made sure they were as inboard as I could get them.

    Here's one of the advance side (which doesn't leak)

    [​IMG]

    And one of the ignition side

    [​IMG]

    They look about the same to me which is why I feel like this isn't the issue.

    I should note that I originally had it installed with the gasket first, then the oring, then the cover. I believed that was the issue but I installed it the other way around and the leak persists.

    Not sure what to do from here. Retorque the head bolts maybe? I've heard of some people cutting the little metal spring around the seal and stretching it to make it grip tighter. Maybe that would help?

    I also noticed that my starter blockoff plug has come loose and is leaking, and also I have drips forming on both drain plugs. I ordered new copper washers for those and will retorque the starter blockoff plug with some more loctite.

    Can't catch a break here at the end it seems.

    Here's a nice glamour shot of her looking good though. Looking forward to seeing you all at the chopoff after I sort out these leaks. Also my mini battery doesn't seem to want to charge over 6V. The list goes on...motivation is a struggle right now.

    [​IMG]
     
  6. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    Alright folks, good news and bad news.

    Good news is that I replaced the cam cover oil seal with a quality replacement from boats.net and the leak is gone! One problem off the list.

    Bad news is that after getting her running and the timing set, I went to take her for a test ride to find a new issue. Bike dies when I shift it into first. This is unusual because I had her running before and haven't been in the clutch side of the engine since. I did make some modifications to the foot clutch setup, but the range of motion on the clutch is not different now than it was then. And even if I manually manipulate the clutch actuator arm beyond where the foot pedal could, it doesn't change the situation. I even bent the foot pedal from stepping on it so damn hard. I don't think the problem lies within the foot controls, but I didn't miss an opportunity to create extra work for myself lol.

    This was before

    [​IMG]

    And this is after, this time around I'll put a hollow rod over the threaded portion (Though to be fair, I'd never be stepping on the clutch pedal this hard in an actual riding situation)

    [​IMG]

    From here, I think I'll try pulling the clutch in and kicking the engine over to see if maybe the plates are stuck. Is that the best way to check that? If I pull the clutch and can't kick it through, then the plates are stuck?

    I'd love to avoid doing another oil change if possible, I heard some say you can lay the bike on it's left side and pull the right cover to check on this without having to change oil. Maybe I can try that.

    Any advice (including requests for me to try certain things that would help pinpoint the problem) would be greatly appreciated, thanks everyone!
     
  7. fredintoon

    fredintoon Fred Hill, S'toon. Top Contributor

    Hi SlowMaintenance,
    it's when you CAN kick it over with the clutch pulled that the plates are stuck.
    I'd say you'll run less risk of an oil spill if you drain the engine before you open up the clutch case.
    The ol' "tip the bike over to save draining the oil" trick ain't as easy to do as it is to read about.
    And "Oh My, what big boots you have, Grandmama!"
    I'd suggest that your threaded pretzel is best replaced by a length of hexagonal bar with tapped ends.
     
  8. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    Ah, I see. I'll give that a try and see if it kicks through with the clutch pulled. I know that it wouldn't roll freely on the ground with the clutch pulled but I also didn't really push it hard because I wasn't aware of the stuck plates concept at the time.
     
  9. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    Alright guys, I had a chance to check some things out on the bike last night and here's what I found.

    If I put it in first gear, and pull in the clutch, I can't rock the bike back and forth. If I try to kick it in first with the clutch in, the bike moves forward.

    This makes it seem like the clutch is not disengaging. However, when I pull the clutch in, I can hear it on the clutch side of the engine. I have a video that shows this but I don't know of any way to get it onto this forum. If someone is interested in taking a look, text me at 860-670-2871 and I can send it your way. It's very audibly coming from the right side of the bike so SOMETHING is happening on that side.

    I pulled the cover to ensure that the ball bearing is still behind the clutch pushrod (two piece on this bike) and it is indeed still there.

    I'm at a loss guys, I tried rocking it with the clutch pulled to break the clutch free and no luck. I tried adjusting the foot controls to increase travel, I tried adjusting the clutch at the worm gear itself but can't seem to get anywhere with that either.

    I've done everything but pull the right side case, so I guess I'm doing another oil change because I can't think of anything else to do and I'm just frustrated. My rear brake setup doesn't have enough travel either so it isn't braking very well. One thing at a time though.
     
  10. robinc

    robinc Member of the 'yellow meter gang' Top Contributor

    Re: the video.
    Create a You Tube account, upload it there, and then copy and paste the link into a post here.
    Video will then show up here.
     
  11. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper



    Shot this in vertical cause I'm trash
     
    robinc likes this.
  12. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Yup, that right cover has to come off.

    Follered by a bunch of finger-pointing at various important things...
     
  13. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    Alright guys, I come bearing photos and videos of the situation! I can see that there's a problem, but I'm not sure why the problem is occurring. That's where I need your help and advice.

    Let's start with the videos, seeing as they tell the majority of the story here.

    Here's what's happening under that right side cover after I removed it (this is before I did anything to the clutch)



    I watched some other videos on youtube which showed the plates moving WITH the basket. Obviously mine aren't doing that. I decided to remove the plates (I have 7 plates and 6 metal spacers) and see what was up with the basket. This video shows what's going on there. Slight play side to side, I'm assuming that's the problem here?



    Because my commute is so long and I can only work during daylight hours, I was already running out of time to work on the bike so I decided to put all the plates and spacers back in before leaving for the night. Before doing so, I dipped them in oil before reinstalling. I put them all back and torqued the bolts to 7ft/lbs. This video shows the difference in action between when I first pulled the cover and after oiling the plates. Sometimes some of them move, sometimes none of them move, but they never ALL move. What's happening?



    That wraps it up for the videos, but I did want to do some additional photo-based finger pointing to key items that I felt you guys might have questions about.

    For starters, the spring to the left of the clutch basket (the one that's often missing causing a first gear slip) is indeed there and it's in great shape.

    [​IMG]

    Next, the shift shaft spring is also in place and in good condition, this is above the clutch basket.

    [​IMG]

    Often people will remind folks to ensure their clutch basket alignment hole is matched with the notch on the basket. Indeed they are

    [​IMG]

    Moving outward to the cover, you can see here that the basket is hitting the case, note the circular skuff marks.

    [​IMG]

    I'm thinking those skuff marks and that case contact are responsible for the shavings I'm seeing here in the filter

    [​IMG]

    Here's a quick shot of the plates themselves, they're certainly not new, but the meat on them is within spec

    [​IMG]

    Last but not least, here's a shot of the middle of the clutch basket, in the event that anything looks off about it.

    [​IMG]

    Please take a look through all this documentation and let me know if anything seems immediately off to you. Again, I know that the plates shouldn't sometimes move and sometimes not move, but I don't know WHY that's happening or how to correct it.

    Thank you!
     
  14. fredintoon

    fredintoon Fred Hill, S'toon. Top Contributor

    Hi SM,
    impressive video skills. Where's the one that shows you trying to kick the engine over with the clutch pulled in?
     
  15. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    How many arms and legs do you think I have? What is this, twister? lol
     
    robinc likes this.
  16. 5twins

    5twins XS650 Guru Top Contributor

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    Your clutch appears to be functioning normally. You won't see all the plates move every time. They just naturally separate on their own when you release the pressure on them. If the shaft was spinning, the steel plates attached to the inner hub would spin between the fiber plates attached to the outer hub with the pressure plate moved out.

    A problem I do see is your foot pedal contraption is moving the pressure plate too far or too much. That's why it's hitting the inside of the cover and scraping. There is a very limited amount of space under the cover there, only like 2 or 3mm between the pressure plate and the inside of the cover. You have to figure out a way to limit the foot pedal travel and/or the amount it's pushing the pressure plate out.

    I'm not sure about the in-out play on the clutch hub. Maybe it's normal but maybe the spacer washer sequence on the hub assembly isn't right. Maybe some of the spacer washers are in the wrong spot or maybe one is missing. The drawings in the older factory shop manuals do omit one and aren't correct.
     
  17. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    Yes, I agree that it's moving it out too much. I have an idea for how to adjust it so that it doesn't push the plate out so far. I'll try that out next time I'm back with the bike. Is there a measurement I can use to ensure I've got it correct? Total distance between the edge of the basket and the inside of the clutch face plate at full extension?

    With regard to the clutch assembly sequence, the one benefit to the painfully slow process of building this bike is that it's allowed me to keep extensive records and photos of all the steps I'm taking. Here's the photo showing all the pieces AND the order in which they were installed. Items on the right hand side go on first, in order, all the way through to the left.

    [​IMG]
     
    figure8 likes this.
  18. 5twins

    5twins XS650 Guru Top Contributor

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    I did a bunch of measuring a few years back when I was switching to a newer oil sight glass cover. These values may not exactly match what you've got but could probably be used as a basic guideline. To know for sure exactly what you're dealing with, you'll need to measure your bike. I kinda think these all differ a little bit. Anyway, here's what I found on mine .....

    The depth of my old original cover was 68mm. The new oil sight glass cover was 70mm, deeper by 2mm. This alone may help you. Switching to a newer cover may give you the added clearance you need.

    My clutch pack, measured to the top of the pressure plate, sat 64.6mm above the gasket surface on the engine. This gave me about 3.4mm of clearance between the pressure plate and the old cover, 5.4mm on the new cover. The addition of the gasket could add about another MM to that.

    With the stock worm gear set-up and adjusted tight, the best I could get for pressure plate movement was just a little over 1.5mm. This is an inherent problem with the 650 clutch - the pressure plate movement is barely enough. It's enough when cold but when hot and parts have expanded, that movement is less. You can start to experience clutch drag and that hard-to-find-neutral problem rears it's ugly head.

    So, finding a way to increase the amount of pressure plate movement would be a good thing, you just can't overdo it because of the limited space under the cover, as you've discovered. From watching your video, I'll bet you have 4 or 5mm of pressure plate movement at least. I'm thinking doubling it over stock, to about 3mm, might be ideal. But like I said, maybe a newer oil sight glass cover may fix the rubbing problem for you too.
     
  19. 5twins

    5twins XS650 Guru Top Contributor

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    If you mount the linkage on your foot pedal assembly to the holes higher up on both brackets, farther away from the rotation point, that will lessen the amount of pressure plate travel. Try to get it down to around 3mm.
     
  20. SlowMaintenance

    SlowMaintenance '76 XS650 Chopper

    That's a good tip, I'll do some digging for those covers and see if I can find one as it could help the situation a bit. I also think that reducing the travel distance via the clutch adjustment could be helpful. There is an adjustment knob on the clutch side, I'll shoot for that 3mm mark. The good news is that I can put the engine cover back on and test if it hits BEFORE filling it with oil again. So that's good news.

    Here's what I'm not getting though. If my clutch is moving MORE than the stock travel distance, and the plates are acting as they ought to, why is it dying when i shift it into gear?

    I don't understand what's causing the problem here. If anything, the increased travel distance should make it even easier for the bike to shift into gear without engaging the clutch.
     

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