An Adventure in Firsts: '83 XS650 Heritage Special Build/Rebuild

@Machine you mentioned the dipstick to check if gas is in oil--you mean just pulling it and doing a smell test?

I'm going to read up on carbs tomorrow as I have no idea how to empty bowls or do a dang thing with those
If gasoline is accumulating in the crankcase oil your dip stick should visibly show the overfill condition. The gasoline is both clearer and lighter (in color too) than oil so the dip stick reading must be looked at closely.
Yes, figure out how to drain those carbs, test the petcock with the float bowl drains open even to see that the fuel does stop flowing in both "on" and "res" positions with the engine off.
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Petcock didn’t leak when I took fuel lines off when removing tank, but I imagine I’ll need to check again.
No, if it didn't leak, you're good. Not sure what checking again would accomplish? It didn't leak... let it be. In order for fuel to get into the engine, you'll need.... 1. a petcock leak. 2. one (or both) float valves leaking. 3. the bike parked on a downhill slope. You've eliminated condition 1, so it's doubtful you're getting fuel into the engine. Moving on.....
Looks like we have a fuel problem: leak, overflow, something. I just had a borderline empty tank when—unless this bike eats gas at a crazy rate, though my last was EFI—I haven’t even ridden enough to justify it being so low since refilling; I’ll do the math of rides v mpg. Started on reserve, got a bit of gas and made it back.
Sounds to me like you ran out of gas. We've all been there. If I had a nickel for every time I went on RES, filled up and forgot to switch back to ON... then ran the tank dry thinking I still had RES... I could go out and get drunk. :sneaky:
Somewhere in here you said you had a 4 gal tank. Marty (I think) corrected that it's a 3 gal tank. Add in all the times you've ran the bike working through your problems and I'm guessin' there's no problem here.
Who was it who said, never underestimate the ability of the electrics to fool you into thinking you have a carb problem?

That'd be me. One of my mentors back in the 70's was fond of saying "never underestimate your ignition systems ability to fool you into blaming the carbs."
He'd also give you a good ass chewin' If he caught you tearing into the carbs before you verified the ignition was working normally. I made the offer earlier to loan you a TCI box so we could eliminate that as a source of problems.... that offer still stands. In fact, I'll sweeten the pot. If it fixes your idle problem, I'll work it out so you keep the box.
RE the gas smell. If it's not overwhelming and or obvious, I'd suggest putting miles on the bike and see if it dissipates over time... or not. I don't see it as an immediate concern.
 
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I should have added that it's still entirely possible that, as 5twins points out, one of (or both) the float valves are leaking, overfilling the bowl and causing the low idle problem. That would also account for the lower gas milage than you were expecting.... and the smell.
If it were me, I'd just as soon eliminate the iggy sys first, but you could disassemble the air filter boxes enough to see the overflows on the carbs, then start the bike and let it idle. If one is leaking, you'll see fuel coming out the overflows about the same time the idle starts acting up.

Edit: Another way to check.... easier too. No need to disassemble the air boxes. With the bike shut off, just turn the petcock to the PR (prime) position. This bypasses the vacuum shutoff and allows fuel to flow into the carbs. If one of the float valves is sticking, you'll get fuel flowing out the back of the carb and dripping out of the air box in short order. If you don't see any evidence of fuel in about 10 min, I'd say it's not leaking. If you do, we'll cross that bridge then.
 
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made the offer earlier to loan you a TCI box so we could eliminate that as a source of problems.... that offer still stands. In fact, I'll sweeten the pot. If it fixes your idle problem, I'll work it out so you keep the box
:rolleyes: do that ! Great offer.
I still am disappointed that the carbs drains haven't been utilized so far? Its a very easy and reassuring check.
Every time a fuel line is disconnected and reconnected there is potential for debris and even small rubber bits to flow and lodge right into the carburetor needle/seat and bowl.
Been there.
BTW, how did the oil filter and gaskets fix work out?
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I still am disappointed that the carbs drains haven't been utilized so far? Its a very easy and reassuring check.
Every time a fuel line is disconnected and reconnected there is potential for debris and even small rubber bits to flow and lodge right into the carburetor needle/seat and bowl.
Yeah, it certainly wouldn't hurt to look and see if debris comes out, but.... On the BS34's, there's a tiny screen on the inlet side of the float valve. Any debris is likely stuck there and not in the bowls or the valve itself. .
 
Got it.;)
I tend to not answer BS34 carbureation questions simply because I have only owned 77-79 BS38 equipped XS's.
But the principal of seeing clean fuel come out of the drains onto a white paper towel is comforting
 
Unfortunately, many of these bikes need a good carb cleaning when you get one. I know you said at the beginning of this thread that the P.O. told you he cleaned the carbs just before you got the bike, but the question is, did he do a good enough job? If you're not familiar with carbs, and these carbs in particular, there are a few small spots or areas that often get overlooked. One in particular is the choke feed jet. It supplies the gas to the choke when you turn the choke on. If it's plugged or partially plugged, the chokes won't work very well, maybe not at all. Yours seem to be at least partially working since there's a difference in the way it runs with them on or off, but maybe they're not fully working. Usually, you can't leave them on for too long or the bike will die. And usually, it's not that long until that happens, only a minute or two at most. You shouldn't be able to run the bike for 10 minutes or more with the chokes on like you said you did.

The choke jet is located off to the side at the bottom of the bowl. If there's any gunk laying in there, when you turn the choke on and it sucks fuel in, that jet is one of the first things to get plugged .....

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The jet is pressed in place so you can't remove it for cleaning. You have to spray carb cleaner through it, or better yet, blow it through with compressed air. Here's how you can check to see if it's clear .....

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You needn't pull the carbs off to do this. You can just remove the bowls using a stubby screwdriver.

Yes, do drain the bowls to see if any junk comes out. I like to use a light colored container to catch the gas. It's easier to see any junk in there. Once drained and the fuel that came out is checked, dump it, place the container back under the carb and put the petcock on "Prime" for a few seconds. This bypasses the vacuum petcock function and fuel will flow out just like on a normal old fashioned petcock. This can flush the float needle and seat area clean if there happens to be some dirt stuck in it.

And yes, check the battery charging. You do want to eliminate that as a possible issue before getting into the carbs.
 
Just noticed this.... looks like the rotor is rubbing on the stator. That indicates that the rotor might not be running true. Are those rub marks as they look Marie? If so, are there corresponding rub marks on the rotor?

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Wow certainly some cross posts with different views on how to do the same thing different ways

Here is what i would do........condensed

1; You have been talking about a battery for a while....Cost vs need........get a Lead acid or Sealed battery. ..........Cheap and will last a couple of years or more....................money saved now can go towards other needed parts or tools, needed to get the bike reliable...................and by then you will have sorted the bike, and be onto the changes you are thinking about and had a chance to save a bit, also learn some, then get a Lithiam battery if wanted.........they are expensive.

New battery may sort the rough idle and associated engine running..............

2; My post #357 is a diagnostic without having to do any dismantling, saves time..........doing this also relates to your wanting to understand how things work and is an easy way to check the petcock and Float valve functions without removing fuel lines or tank which can dislodge fine bits of grit and block the carbs.........will also help to diagnose that fuel smell without having to remove filters............If the fuel smell persisted check all fuel lines for cracks or leaks at the fittings and any signs of fuel, will leave a brown stain on alloy, leaking.....................If your still smelling fuel then remove the filters and do as Jim suggests in post # 363

As 5Twins states that choke jet is a notorious problem...........Draining the bowls will help to indicate the condition, (lol dirt is dirt), of dirt in the the bowls and in turn the chances the choke jet could be partially blocked.......................At some point you would be advised to work on the carbs for your own sake of mind and as a maintenance issue that makes for a good running bike........be surprised how simple they are to work on after a time or 2
 
Yes, I couldn't agree more on the battery making it seem like there's a carb (or EFI/gas) problem. I saw the battery on my last bike take a full charge and read as charged on tender, but it seems it would not keep it as the idle would drop at stops. Got a new battery and problem was solved. I just figured this one was okay (at least for a bit longer) since when I did the the sitting test, the rev test, and the load test about 1-2 months ago, it passed. But at this point it's still a dangling question and getting a new one is the only way to know for sure.
And as several of you have noted, I agree that it doesn't mean I may not also (or even exclusively) have leaking float valves. There is the gas smell, and I'm still a bit suspicious of the rate of gas consumption, but it could certainly just be my bad.

Sounds to me like you ran out of gas. We've all been there. If I had a nickel for every time I went on RES, filled up and forgot to switch back to ON... then ran the tank dry thinking I still had RES... I could go out and get drunk. :sneaky:
Thanks for that, haha. I felt like quite the dullard seeing that I was low/out of gas--still just doesn't seem to add up that it went quite that fast but perhaps I wasn't paying close enough attention to it, and yeah, I've been having to run/idle it for a long time and with a fair amount of choke, which is hard to account for how much gas that takes. Been used to having a fuel gauge. Certainly will be checking it more often now!

No, if it didn't leak, you're good. Not sure what checking again would accomplish? It didn't leak... let it be. In order for fuel to get into the engine, you'll need.... 1. a petcock leak. 2. one (or both) float valves leaking. 3. the bike parked on a downhill slope. You've eliminated condition 1, so it's doubtful you're getting fuel into the engine. Moving on.....
Got it. Thanks for the recap. I'd figured perhaps I put the hoses on poorly so it wasn't the petcock leaking but the hose not being sealed enough; but again I haven't seen any drips from there either. Just questioning my work and eyes I suppose

BTW, how did the oil filter and gaskets fix work out?
Ordering those today too. The filter went in. I haven't taken cover off since, nothing oozing out of it so hopefully I'm fine riding it (when I get it to again) until the new one(s) arrive.

SO, PLAN:
--look up batteries tonight and (hopefully) choose and buy one
-- @Jim Re the TCI box. That's an awesome and very generous offer, thank you! Sorry I didn't respond to it sooner, just been trying to sort my head from my ass and then what to do with it and all this information when I have limited knowledge to even assess which to choose first. I'm definitely up for it, but to save you the hassle of sending something, it seems it's wisest for me to FIRST try the battery once I get it and it arrives, and to try what you suggest below, and take a closer read at @5twins suggested in #367 and what @650Skull suggested in #357 and try those too
Another way to check.... easier too. No need to disassemble the air boxes. With the bike shut off, just turn the petcock to the PR (prime) position. This bypasses the vacuum shutoff and allows fuel to flow into the carbs. If one of the float valves is sticking, you'll get fuel flowing out the back of the carb and dripping out of the air box in short order. If you don't see any evidence of fuel in about 10 min, I'd say it's not leaking. If you do, we'll cross that bridge then.
To be clear, you mean I just look to see if it's dripping from air box in that time? Probably remove to see if they're wet at all?

Thanks as always everyone. Sorry if it's slow over here, I just ask you keep in mind that while many of these solutions or checks are simple to you guys, this is all first time stuff for me, so anything I do, i have to stop and figure out which suggestion I'm taking and why, what the parts are, where it is, how to handle it, what tools and supplies I need, then go get them and where, and IF there's time why and how they work together. And clearly there's been several things going on at once between idle and electric and oil filter and gaskets and valves and washers and and and almighty time and life waits for no one :eek: Carbs are daunting but I'm actually excited to get into it a bit as I know I'll need to and it seems interesting, and yes I'll finally be able to start to understand how they work more. So anyway, thanks for your patience and thanks for all the diagrams and steps and specifics you guys have just provided.

You shouldn't be able to run the bike for 10 minutes or more with the chokes on like you said you did.
Ahaaa. This being clogged would also seem to explain why it needs more than usual and why it's so sensitive to me backing it off just a touch when it's been on for a while already..

Just noticed this.... looks like the rotor is rubbing on the stator. That indicates that the rotor might not be running true. Are those rub marks as they look Marie? If so, are there corresponding rub marks on the rotor?

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I'll check that out today!
 
The next time you go to work on the bike, check the bottoms of the carbs first thing. Look at them and run a hand over them to see if they're wet with fuel at all. If they are, that would most likely indicate the bowls are slowly over-filling as the bike sits. Even if the petcock is working properly and not leaking, the fuel in the lines can drain into the carbs and that is often enough to over-fill them. You won't get a huge leak from this, a giant puddle of gas under the bike, but it's wasteful of fuel and might explain you going through that full tank so quickly.
 
Just noticed this.... looks like the rotor is rubbing on the stator. That indicates that the rotor might not be running true. Are those rub marks as they look Marie? If so, are there corresponding rub marks on the rotor?

View attachment 182604
So I checked it out. Those marks on the stator do seem to be some kind of scrape. I did not however find any definitive corresponding marks on the rotor. What I did discover when I tried to put the stator back on was a little broken off piece from one of the teeth like things that secure the stator. I have no idea how it broke and certainly couldn't be responsible for making marks on inside of the stator.
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The stator is usually a little fiddly to get back on to seat properly, but tonight I couldn't get it to go back on all the way--yet again, it was dark and I was hangry. I can look tomorrow.
Little confused as to what's doing this but wondering whether the uneven wear in the brushes is also indicative of some kind of instability/untrueness in stator or rotor.

Just to make sure I didn't miss anything, I'll note what else I saw. Did notice that in one spot the sealant or whatever that yellow sealer on there is has chipped off, and the areas with the divot (right arrow) have a sort of worn looking metal piece but I sense that's how they're meant to look--not to mention these divots are equally spaced around rotor so it wouldn't make the marks I saw.
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Some wear in one spot but not enough I'd think to make those marks
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sorry pics aren't the best, light escaped)

I tried this as well today:
Edit: Another way to check.... easier too. No need to disassemble the air boxes. With the bike shut off, just turn the petcock to the PR (prime) position. This bypasses the vacuum shutoff and allows fuel to flow into the carbs. If one of the float valves is sticking, you'll get fuel flowing out the back of the carb and dripping out of the air box in short order. If you don't see any evidence of fuel in about 10 min, I'd say it's not leaking. If you do, we'll cross that bridge then.

Test done with bike on side stand--didn't have anyone around to do the center stand assist. No fuel came out into air filter as far as I could tell; waited in excess of 10min. It may be worth noting I still don't have a full tank--so if that's needed to try this properly, let me know. It's not empty of course, but it's about a 1/2 gallon or a bit less, what I got from 1/2 canister to get home. Before and after the test the filters smelt like gas. Both dry to the touch before, but if I'm being really precise, when compressing the sponge around filter with my finger, I get a tiiiny bit of oily residue on my finger. Same state on all fronts after test.
This is what the left carb opening looked like before prime test. There's a tiny amount of fuel where the arrow is pointing. Looked the same after the test.
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I imagine I should still go ahead and do the other tests. Going to try to get at them tomorrow if I have time after finding a battery etc

Just saw your last post 5Twins as I was posting
The next time you go to work on the bike, check the bottoms of the carbs first thing. Look at them and run a hand over them to see if they're wet with fuel at all. If they are, that would most likely indicate the bowls are slowly over-filling as the bike sits. Even if the petcock is working properly and not leaking, the fuel in the lines can drain into the carbs and that is often enough to over-fill them. You won't get a huge leak from this, a giant puddle of gas under the bike, but it's wasteful of fuel and might explain you going through that full tank so quickly.
Thanks, I'll check this out tomorrow
 
It's normal for the outer brush to wear more and faster than the inner brush because it covers more distance with every revolution of the rotor. You can swap the brush locations every now and then to even out this wear if you like. You might want to start watching eBay for some replacements. You can usually find originals for about the same price, sometimes even less than aftermarket ones. I prefer originals, I think they're made better and last longer. This is what you're looking for, same brush fits inner or outer position .....

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So I checked it out. Those marks on the stator do seem to be some kind of scrape. I did not however find any definitive corresponding marks on the rotor. What I did discover when I tried to put the stator back on was a little broken off piece from one of the teeth like things that secure the stator. I have no idea how it broke and certainly couldn't be responsible for making marks on inside of the stator.
That broke "finger" is one of 8 that makes an alignment cage for the stator. Although broken pieces are seldom good, you still have 7 left... should be plenty to hold it in place. Makes me question all the more whether the rotor's running true. Perhaps the impact of the rotor touching the stator broke it? Dunno. Are the majority of scrape marks on the stator in the area of that finger? This is gonna be a pain, but what I'd suggest is taking a big fat black or blue magic marker and color over the scrape marks in the stator and any suspect areas on the rotor. Put it all together and run the engine 'till warm, take it all back apart and see if the marker's rubbed off in any spots on the stator and rotor. If it is, it's gonna need fixin' before you break another finger.... along with whatever other mayhem that might cause. One big reason I'm concerned is I've had 2 of those rewound rotors you have with the yellow epoxy just glooped on..... both were bent during the rewind. Yours would make it 3 for 3.

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The stator is usually a little fiddly to get back on to seat properly, but tonight I couldn't get it to go back on all the way--yet again, it was dark and I was hangry. I can look tomorrow.
Most likely you did notice a small alignment pin down around the 6:30 position underneath the rotor? The Stator has a corresponding slot which does fit fairly precisely on that pin.. That Stator does need to go in aligned correctly.
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About that rotor, Jim is aware of possible "runout" happening there. He is the GoTo for the best rotor replacement but, I do have this old 82 rotor which is still basic ohm testing good if a temporary fix rotor is needed.
-R
 

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Just went back over the pics and the scrape marks (if that's what they are) definitely look to be in the area where that finger broke. I'm getting wildly speculative here... but a dragging rotor... were it that bad, could also drop the idle when warmed up due to the drag. Again.... wildly speculative at this point.... but it needs investigating.
 
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