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Leaks and stuck RPM (high) even with clutch in. 83' xs650 Heritage Special

Discussion in 'The Garage' started by MarieKaramazov, Sep 17, 2020.

  1. gggGary

    gggGary I'm listening, change my mind XS650.com Supporter Top Contributor

    I'm usually with Jim but if you remove the LH cover usually a bad leak will have cleaned off the grunge in an upward pointing ^ the peak of the ^ will be the source of the leak. I'm still betting on clutch pushrod seal, but you will want to also do a head stud retorque soon to very soon.
  2. Raymond

    Raymond XS650 rider, fettler, setting out on a journey XS650.com Supporter Top Contributor

    Hi Marie, well done for taking this on, can be a bit daunting. This side of the pond we call it jumping in with both feet. First thing is not to worry too much - everything mechanical can be fixed. If you make mistakes it will just mean re-doing or at worst if you break something you will need to repair or replace.

    Quite a lot of points in your post, I'll only address one or two just now.

    You mentioned working in the street - do you have a garage/basement/shed/bedroom you can work in? Makes things a lot easier.

    You suggested removing the l/h engine cover. Fairly easy to do and you don't have to worry too much about correct torque settings when you replace the cover screws. Just don't over-tighten them - the steel screw will strip the thread in the softer alloy engine case if you do but you would need to go gorilla on them. A bit of finesse is required.

    Torque settings are more for critical areas such as cylinder head bolts, engine mountings and such like. Makes you feel like a proper mechanic when you use a torque wrench though.

    Good advice from Jim - and the others too - clean the engine and you'll spot where oil is leaking more easily. Run the engine with the old oil to see where it's leaking from. If you need to remove the sump, that's where the forward drain plug is situated, to fix a leak you'll need to drain the oil so it might as well be the old stuff.

    There is enjoyment to be had, it's very satisfying when you've done a job yourself and the sense of involvement when you ride a bike you've worked on is an experience beyond price.
    Last edited: Sep 20, 2020
    MarieKaramazov, Jim and Greyandridin like this.
  3. bikefreakjon

    bikefreakjon XS650 Addict

    Your description of the intermittent hanging idle definitely indicate that you need to either clean the carbs or adjust the mixture better
    MarieKaramazov and Greyandridin like this.
  4. MarieKaramazov

    MarieKaramazov XS650 Enthusiast

    Spark plugs. Judging from the condition pictures I compared these to, they look like they're okay to maybe a bit hot/lean--funny cuz I thought I was going to see a rich condition plug. But then I rode it last night (only 1st & 2nd gear around the block for about 15min--idle didn't get stuck) and then checked the plugs just now-- looks like I'm getting more black. Not wet. Gonna keep looking at diagrams but figured I'd post.
    Below: Yesterday (left)

    just post em yS9e3lEWT8+e5m1zgN6%5g.jpg
    Below: today (left)

    Below: Right cylinder (yesterday)
    Below: right, today
    There was the tiniest touch of oily residue on right one, could have been from pulling it from the grungy area (whole thing needs a clean!). Plugs definitely aren't the same. Bit more of a rose hue on the left one and more black creeping up the center.
    Greyandridin and Raymond like this.
  5. 5twins

    5twins XS650 Guru Top Contributor

    Plugs look OK, about right. That second darker reading you got may be due to cold starting using the choke. That will blacken the plugs up and it takes several miles of riding to burn them clean again. You probably didn't ride long/far enough to do that.
  6. Jan_P

    Jan_P XS650 Addict

    Looks good to me
    Color wise ..but one can see on the part outside that they have been sitting there for a while
    And since spark plugs are cheap ( Where I but them ) 4 or 5 $ a piece and part of normal every year ( more or less ) pre season service.
    I would replace those.
    If I remember it correctly the procedure the experts use checking plugs is a little higher revving engine warm.
    Shutting it off clutch in and let it roll to stop and then watch the plugs
    Never done it myself. Need gloves and tools out on the road. More needed i suppose on more sensitive engines after tuning and re Jetting.
    The carburetor are now not getting stuck and what i meant with getting a few miles on it ( besides the more important things mentioned before re -tightening and clean the tank.)
    The need for tank cleaning perhaps now is over since you ride and things are getting better
    Perhaps the previous owner have info . But it is a risk. Have you looked into the tank with a flashlight ?
  7. Raymond

    Raymond XS650 rider, fettler, setting out on a journey XS650.com Supporter Top Contributor

    Things are looking up. One thing I've learned on this very helpful forum is that these bikes often take a little waking up after a long period of not being used.

    If the bike is happy to run and the idle not getting stuck at 3,000rpm, then IMHO attention should go on cleaning up the engine, seeing where the oil leaks are and giving the bike a service.

    The classic 'plug chop' involves riding the bike hard and killing the engine while under load. But that is a technique appropriate for setting up the fine tuning of carbs and not something you need to worry about just yet. If ever.
    MarieKaramazov, Jim and Greyandridin like this.
  8. On draining the oil,
    A 1/2" drive breaker bar with the proper size socket, a length of steel pipe to go over and extend the length of the breaker bar for more leverage, bike up on service stand and an assistant to hold and keep the bike from falling over as you go King Kong on getting the plugs out..........

    Alright, a bit of hyperbole but if you're doing it solo the thought of an assistant might come to mind, especially on a 'new to you' XS. You'll see.
    lakeview, MarieKaramazov, Jim and 2 others like this.
  9. MarieKaramazov

    MarieKaramazov XS650 Enthusiast

    Thank you as usual everyone.
    Hey Jen, yeah, I bought new plugs the other day just to have on hand and since I figured there were going to be old. I checked in the tank with a light before I ran it or bought it; didn't see any rust. He didn't get rid of the gas that was in there though; he said it smelled fine and then added more. If I find time, I'm thinking I'm going to empty and remove gas tank and put in fresh just in case and i need to remove it to get to some other stuff anyway.
    Is there a specific way to check for rust once it's empty except just poking in with a light the same way? Saw a touch of surface rust inside the cap-- I read apple cider vinegar can be good for rust?

    @Raymond Agreed on the order of attention, except unfortunately the the idle is still sassy and I feel like I should address that first. I took it out today again for about 10min and started out fine--except it really didn't want full choke at any point, I can only go halfway otherwise the RPM shoots right up, and then I back off the choke as it warms/as RPMs go up until I'm at 1.2 no choke. Interestingly though, when I took it out today, and it got stuck around 2.5k-3RPM, if I slowly opened the clutch and feathered it a bit in the friction zone, no throttle, the RPM would drop back down as the gear engages--and I could pull clutch back in completely and it'd stay low. Ride to next stop sign, it'd be stuck up there again by then. Same trick would drop it back down.

    Anyhow, overall, where I"m at right now is trying to learn as much as I can about carbs so I can address the idle issue properly.
    Tried to pull the LH cover yesterday (figured I'd poke in there while waiting on solvent), but it looks like the tool I have doesn't work for it though it seems to fit nothing moves--someone said I need to get metric Allen key instead of inch one. Doing that tomorrow.
    After or while I'm moving towards the idle issue solution I'm going to clean the engine and find the leak, retorque head bolts, and work through routine maintenance and start ordering things I know I need--like new tires--at which point I'll be starting a much more excited build/rebuild thread, and then we can talk about other fun things

    Oh, pulled the air filter out yesterday too. Sponge is all yellowed, and rubber seal looks pretty worn--I'll post a pic tomorrow. I was going to clean with compressed air, but alas, I don't' have any at the moment.
    Greyandridin, Raymond and Jim like this.
  10. Jan_P

    Jan_P XS650 Addict

    Short thoughts ..
    I have not read it fully so I cannot remember what year model and Carburetors you have .
    But in my View it is to early / soon to look after defects in the carburetor .
    3 -5 tanks with full fresh gas through perhaps more. Before doing that if the bike is running reasonably ,well
    And perhaps after use of those cleaning chemicals mentioned before.

    At your post # 19 at 11 o clock in the left upper corner is a small screw with a spring around it.
    That one is the idle rev adjuster Counter clockwise Lower Clockwise Higher

    I do know that on my 1980 if the idle screw is set with to high idle it can have problems falling down to the right idle rpm.
    When letting go of the gas as well as when shifting gears on the road.
    I turn that one screw by hand now and then. Lubrication of wire plays a role. Something that can change after a while on the road.
    The screw is hitting the carburetor arm which you can manually press on with the hand -- if to much friction in wire.
    To be sure it is getting back to the right place.

    It is a slotted screw by the looks of it I have a different one.
    If your idle is high .I would try to turn that one counter clockwise. Count the amount you turn it fex in quarter turns .
    So you can set it back if it does not change to the better.
    I am not sure of the right value 1600 -1800 rpm perhaps Dont remember ;If to low the bike stalls.
    MarieKaramazov and Greyandridin like this.
  11. 5twins

    5twins XS650 Guru Top Contributor

    Stock idle speed spec is 1200 RPM and keeping it in the 1100-1200 RPM range seems to work best. Much higher and the idle speed can hang, much lower and you can get random stalling.

    Sounds like you need to "tool up" a little bit, lol. As you've no doubt discovered, you're going to need metric tools. If you have a HF nearby, you can get started with some stuff from them. They have the metric Allen key sets at a good price, also Allen sockets. You'll want some metric wrenches and sockets too. For the size range, try to get sets that cover from 10 to 19mm. There are a few larger individual sockets or wrenches you may want to invest in too. Probably most important will be a 27mm size. This fits your oil drain plugs, the lock nut on the cam chain adjuster, and your rear axle. A 22mm size will fit your front axle nut and the cover nut on your cam chain adjuster.
  12. MarieKaramazov

    MarieKaramazov XS650 Enthusiast

    @Jan_P @5twins
    Yeah, thing is that when I start it and am warming it up, it idles fine around the 1200 mark once warm (1min) and choke is off. But perhaps the reason it doesn't want full choke when starting (I can only put it on 50% choke and then I back it down as idle settles) is that it's too high to begin with and then as I ride it (now with choke off) and it warms even more, the idle shows itself as too high?...if that makes sense. RPM increases as I ride it and the longer it idles.
    I'll turn it down today and see if I get anywhere and get to changing the gas out. Side note: I saw a post about high octane... I don't have that on hand nearby, and someone else told me to do super unleaded instead of regular. Any thoughts on regular v super for this pass?
    And, yes, "tooling up" is definitely in order! haha. Thanks for those size references!
    Greyandridin likes this.
  13. 5twins

    5twins XS650 Guru Top Contributor

    Well, the bike will run on regular gas, but it will run better on the premium. It's also less prone to ping with the Super. It's not like you have to fill a 20 or 30 gallon tank, it's only 3 or 4 gallons at a time, so I doubt the higher cost is going to put you in the poor house, lol.

    If your idle speed adjustment screw was set too high, I don't think you'd be able to knock the RPMs down the way you've been doing by partially letting the clutch out in gear and have it stay. Sure, that would drag the RPMs down, but I think they'd just promptly return to the higher setting when you pulled the clutch back in or sat there in neutral. Main cause of the hanging idle is usually a lean condition, like a minor air leak somewhere. But there can be other causes like bad carb adjustments. The mix screws may be off or their settings mismatched, or the sync may be off.
    Greyandridin and MarieKaramazov like this.
  14. Jan_P

    Jan_P XS650 Addict

    Hmmmmm ..mm

    Oh, pulled the air filter out yesterday too. Sponge is all yellowed, and rubber seal looks pretty worn--I'll post a pic tomorrow.

    And as 5 twins says

    Main cause of the hanging idle is usually a lean condition, like a minor air leak somewhere.

    So perhaps the air filter and rubber seal is something to look into first.
    I do believe that professional Mechanics would remove those dodgy filters entirely for a short test.
    No ride just on the yard.
    Trying to start and see what changes .How throttle response and so.
    But air filters Need to be right. And more miles .. Before adjustments besides idle is done.
    Was there a breather tube not in place .. ?
    I don't see any major problems yet since the spark plugs looks OK.
    I would check the air filters perhaps glue on other rubber gaskets or replace filters but they are expensive I believe.
    And tightening the intake ..screws ..so nothing is loose.

    I dont think I ever had an idle under 1500 if my rev counter is showing right.
    But I have seen on the Internet that US bikes have a better idle than mine
    I wonder if that is one difference between European and US models
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  15. Raymond

    Raymond XS650 rider, fettler, setting out on a journey XS650.com Supporter Top Contributor

    Leaky air filters unlikely to cause the high tick-over. Though badly blocked (dirty) air filters can cause a rich mixture.

    5T is probably thinking about an air leak down stream of the carbs, for example, the vacuum take-off tubes on the inlet rubbers (not all models have these) or the rubbers not fitting hermetically to the head or even cracks in the inlet rubbers themselves. Have a search on this forum for simple tests for leaks in this area.
    MarieKaramazov likes this.
  16. Jan_P

    Jan_P XS650 Addict

    Yes Sir leakage test ... The basic things is simple to do...spraying chemicals outside listening for increase in rev.
    But come to think of it I have had that to .The times I have had that the engine misfired a bit. Once it was the petcock vacuum hose that was cracked.
    Making it misfire on one side only --- Poff ... at idle on left side.
    Madam K has not mentioned any misfiring yet or at one side only.. if I read good enough. --- But leakage test and tightening up as well as filter service Yes Yes Yes
    gggGary likes this.
  17. gggGary

    gggGary I'm listening, change my mind XS650.com Supporter Top Contributor

    Does your idle screw extend about this far below the bracket?
    idle screw.jpg
    It will not be less than this, but if it is screwed in much further, it's a sign that something is not right in engine or carbs. A hanging idle (what you describe) is often a sign of poor throttle sync, while the sync is easy to adjust it's hard to get right without vacuum or sync gauges.
    MarieKaramazov likes this.
  18. Jan_P

    Jan_P XS650 Addict

    Can be seen in post #19
    I would still wait if possible ..Since the plugs looks good.... getting more miles ...
    Usually things change after a while. Hoses in place and tightening screws and clean tight filters first.
    at post # 19 it appears as if there is no Hose clamp at all on the intake
    pos 20


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  19. MarieKaramazov

    MarieKaramazov XS650 Enthusiast

    @Jan_P As for miles and products like the Berryman B-12--I heard good things about using that to clear out things in a sitting bike before going deeper. Thing is I need to run it at high speed and go through 2 tanks to try that fully and I have to get new tires before that happens--I have a 40 year old tire on the front (looks stock!) and an 11year old on the back. I was going to do those trial today when I double checked the age dates...So can't go far or too fast till I get new ones on there. Trying to choose and order those today, that is if life feels like being nice and I can find ones I can afford and that aren't the worst in look and function. Really like the look of this Cheng Shin tire on the front. I was also concerned about upsetting the engine by running the bike with the RPM that high every stop and without it actually propelling the bike anywhere... Also, which screws are you talking about? sorry if you already mentioned, I May have lost track

    Here's pics of what I'm looking at re: idle screw position, air cleaner, and hoses I can see. Figured I'd post in case you guys spot something out of order I don't see. I noticed that the hose connecting to the petcock leans against the cylinder head cover, and there's a slight mark where it's been heating up that hose...tried to move it so it doesn't lean on it, but feel like it's going to just flap back when I'm riding; may need to re-maneuver that later.

    @gggGary I imagine you mean the bracket into which it's screwed, and if so, it looks like mine is at the same level.

    Here's some reference photos of the air filter/cleaner current condition and wear on gasket in there. Manual says to just blow air through and out of the air cleaner, which was going to do...but the gaskets look beat up, especially on the left, so I feel like I should replace. They're both dry but both smell like gas, as I imagine they would given their location/purpose.



    Also looks like the gasket connecting carb to the cylinder intake has some cracks.. one connecting carb and air filter doesn't look to young either--especially true of left side. Air leak potential there?


    Air Leak @Raymond @5twins
    I just found a good thread. Looking like my options are to spray either carb cleaner/accelerant/soapy water...but where exactly? Some say spray accelerant or carb cleaner "around" that area--so am I just literally spraying into the air next to the carbs and looking for an RPM burst? Onto the carb seams? Or am I spraying it where the carb connects to the cylinder/inlet valve and/or to the joint connecting the air cleaner and carb? Or just everywhere in that general area? Apologies if that sounds silly--juwt making sure whether it's anywhere air can get in (basically any seam in that area) or if you're thinking just intake/carb connections or carb/cylinder connection points. Side note--if it was an air leak causing a lean condition, wouldn't I have seen that in the spark plugs?

    Re: oil leak. Tooled up a bit and mineral spirits just arrived. To be crystal clear--is there anything I should NOT spray/wipe/soak with the mineral spirits, or keep away from? Besides obviously anything electrical. Hoping to go through and clean as much as I can so I can see things better. Trying to solve/try one thing at a time so I know what the answer/issue was, but I think I should be fine cleaning and taking a look as the high hanging idle and oil issues seem unrelated

    Soo for now, big picture= get new tires, try to find air leak while I wait on those (as well as clean engine/assess oil again, carb research). One day, one day I'll be able to do things.

    Attached Files:

    Greyandridin likes this.
  20. 5twins

    5twins XS650 Guru Top Contributor

    Your intake boots (last pic) do look pretty bad, lots of cracks. They could very well be the source of air leaks and that could be the cause of your hanging RPMs. Good news is the BS34 intake manifolds are still readily available and the cheapest, compared to manifolds for the earlier BS38 carbs. The best ones come from the original supplier, ARS. You can often find them on eBay for a good price. The rubber fittings on the air fiter side aren't as important. Air flows in that end anyway so some small leaks won't hurt anything.

    The foam in the filters is naturally yellow like that so as long as they're not torn or deteriorating, they're probably OK. Just gently blow them clean (from inside to outside).

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