cegan09

Everything I found was your standard regurgitation of the press spec sheet from when it was released. Basic engine info, tires sizes, overall dimensions, stuff like that. Thanks for pointing me to that page, seems to have everything. Now I can start researching parts to move forward with.

Your google power must exceed mine. Every site I found with specs didn't have those numbers. Thanks.

I'm looking for specs on the front end of the XS500. Namely the rake angle and trail. Technically I can work out trail if I know rake angle thanks to basic trig. I'm back at work on my bike finally, and I want to convert the front end to modern suspension. But I want to try and keep it close-ish to stock dimensions if I can. I just don't have the stock numbers to start. If anyone has been through this with the XS500 i'd love to see what was done, but my searching has turned up nothing for this bike. The tripple guys (750 and 850) seem to do this often enough.

what carbs does yours use? My 500 has Mikuni carbs, which if my memory is working correctly (often not the case), are CV carbs. My friend's KZ400 has Keihin carbs, and for whatever reason those accepted pod filters with no problems. Mine was suffering from hanging revs, constantly running lean, insanely hard to start, and an inability to idle. Most of these seem to have been fixed with what i've done. I'm not too worried about that. the foam i'm using is from a pair of filters that was nothing but foam. It's flexible, in good health (not dried up), and was meant for this use anyway. I just need to secure it inside the pod filter a little better (not that it could ever cause damage. it can't make it through the carb, it would stop at the slide).

So i'm finally getting serious about getting this bike back to good condition. Issue number one was wiring. fixed that by just making a new custom stripped harness. Issue number two was the fact that i'm running pod filters. I've upped the jets and upped the jets, but it was still just not running right, and frankly it was running dangerously lean (i came close to overheating it the other day). from my reading, my theory is that without the restriction and resulting slight vacuum from the stock airbox, the carbs don't pull fuel through like they should. In addition the slides won't respond correctly. The pod filters offer little to no resistance (usually a great thing for performance), and as such the bike won't run right (as many have much experience with) so here is what i've done. Since i have no interest in getting the stock airbox i've been trying to imitate it. My first attempt was to tape off half the filters, but that really didn't do anything. Then i looked at the filters that came on my second bike. They were foam cylinders with large springs inside to keep their shape. I pulled out the springs, cut them down, and fit the trimmed pieces inside the pod filter. This seems to have helped. temps at the top of the engine are a good 40 degrees cooler than the other day when it was close to dangerously overheating. Pops are about eliminated from the exhaust. Biggest problem was the vacuum from the engine starting to pull the foam into the carb opening. This blocks the air slot to the top of the carb, and kills that cylinder. A little superglue should solve that problem. So, anything blatant i've overlooked? Have others already figured this out and i'm just late to the game?

Sigh. i should really check things before giving them up for broken. I had adjusted the carb balance screw too far in one direction, and yes, it was running on one cylinder at idle. Had to take the carbs off to see it. Figured out timing too. The advance mechanism had gotten stuck open. Pulled the assembly out, and re-seated it, it moves freely now. Just waiting for the battery to charge back up and i'll re-set the timing and get the balance back where it needs to be.

Ah, i missread what you were saying. Yes, that adjusted in the middle is what i was trying to set. Guess i'll pull the carbs first and see if they look really out of whack.

I'll try and address these points today. These carbs have only one throttle cable, so both butterfly valves are opening at the same time. The idle adjustment screw is actually backed out as far as it will go, so the throttle stop arm isn't even touching it at full closed. I believe the engine is running rather lean at idle, something i'm trying to address as well. I just wanted to get them close to synced before i went changing things in the carbs again. My diaphrams are brand new, so there shouldn't be any holes, but i can check them again. Valve clearances were set less than 1000 miles ago, but i suppose it can't hurt to check them again. I'll look at the points gaps and see about adjusting them as well. I'm still learning this stuff, so i appreciate the assistance with the learning curve. One other question. On the piece in the picture above, the shaft that protrudes from the center has a collar on it that is what the points actually slide along. That collar has a section that is thinner than the rest, making it basically a cam shaft. The collar can be removed, and can actually be installed 2 ways. Now i don't think I've messed with the one on the bike, but i've messed with one from the spare engine, and turned it around before noticing it was cam shaped. Am i correct in saying that it is important to have that on the correct way, and how do i know which way is correct? There is no indication on the parts themselves, and i didn't see anything in the shop manual.

OK, still working on the bike, turns out i don't have as much free time as i thought. I have a few things i'm trying to diagnose so i can fix them. 1. Timing. I went and checked it the other day, spot on, tightened the screws on the plate, still spot on. I take a spin around the block to see how it's riding, then check again, way advanced (this is all at idle when i'm checking, so the advance cam shouldn't be on). I adjust, and have the plate rotated as far as it can go, and it's still not quite where it needs to be. It's running much better now, but i'm concerned that it's as far turned as it can get, and is still not right. picture below shows where the mark is with it in this position. 2. Carb sync. I built a simple sync tool, and i'm getting conflicting results. At dead idle (throttle as closed as it will go, the left cylinder pulls significantly more. As soon as you ease into just a little throttle the right side pulls significantly more. How do I remedy this? I'm not even sure what would cause it. I do think one cylinder is running richer than the other, so i'm thinking that is playing a part in it, but i'm not sure what i should set for, closed throttle, or open.

If you have the drawings done, any chance you'd share? When i got around to it i was going to do the same thing, but if you have it done i'd love to have a local shop make one for me as well. PM me if you're willing to share the drawings.

Thanks again Drewpy, line to the right seems to make sense. I just wanted to check before i screwed up the timing too bad.

Thanks Drewpy. Just to clarify, which line do those go with. there are two lines on either side of FR and FL. I just need to know which line it should be lining up with. The book shows much fewer lines.

I'm trying to reset everything on my bike, but i'm having some issues with the timing. I've got a timing light, but i'm having issues with the markings on the rotor. The markings don't match what the factory manual shows. can someone point out which markings are which on this rotor?

well i guess this is why i posed the question. In my head it would simplify the whole electrical system. But back to the original question. If i were to split the bike into two systems, one for running the bike and one for lights, gauges, etc, how big of a battery is needed to run the bike?

1. Since the plan was to have different voltages in the two systems, charging them both would require some complicated wiring, and i'm trying to reduce complication. 2. Why not? Modern LEDs have advanced so far that i see no problem with it. Just use an array of them in the housing to get the right light dispersal. Then you look at the fact that they are using so little power. I've seen harley guys with secondary lights mounted where the fork attaches to the wheel, all LED, and i think they throw more light than the normal headlight.

Projects are back on hold for a bit, and i suspect that over the winter i'll be finishing both 500s. I'm curious about batteries, and how small i can go. My specific idea at the moment is to create two separate systems for the cafe bike. There would be one system for running the engine, and one to run the lights and gages. so for running the engine, how small of a battery would be acceptable? Obviously 12V, but what amp/hr rating. No electric start, just kick start. Recharge system obviously will be retained. My logic here is to then convert every light on the bike to LED and be able to run a lower voltage system for all lights and gages, and just have to recharge the lighting system battery between rides. Since i'll be riding this bike less often than the other 500 i'm ok with this.

this whole old vehicle thing is such a learning process. Chatted with my agent today. It's being entered as a 650, then paperwork to correct it. Works for me. I just think it's funny that no one things there is an XS500 in 1976.

I've tried with progressive, Gieco, and I'm insured through Liberty Mutual now. Neither of them have it in their system. Progressive told me my VIN was invalid. I'm hoping the agent can enter it as a 500 manually.

I'm trying to set up insurance, and no one seems to believe that yamaha made a 500 in 1976. Has anyone else encountered this? Their systems just don't have a 500 in them. I can just tell them screw it and make it a 650 or 400, but i don't want that coming back to bite me later. Anyone successfully insure a 500 as a 500?

Negative terminal on the left, positive on the right. I don't have any info in front of me, but that model number looks right.

the problem might have been the same. The issue i had was that it was stuck to one side of the frame, and not the other. So every time i hit it, it would move a little on the nut side, and just flex the frame a bit without giving on the other. the solution was finally to tilt the frame on it's side, put a block of wood between the ground and frame, then hit. This forced all the energy into the bolt, and it came out. also that bolt was so corroded and pitted that i was never going to use it again, so i didn't really care if it was damaged.

figured i'd give an update. My project is slow moving. The bike is together, and running. I'm working on getting the tuning right, and am getting closer. I did almost overheat the engine in traffic the other day, and need to investigate that i didn't damage anything, but i think it's fine. The kick start started to die, it's now very stiff, so i need to investigate that. I purchased a second xs500 off another forum member today. With this purchase i now have 3 engines, and enough other parts to build 2 bikes. My plan is to build up two rock solid engines and 2 bikes. One will be the one in this thread, which will stay largely in the form it is in now. The second will be the one i bought today, and will be fully done up in cafe racer form. I will start a new thread later this year when i start on that project. My hope is to have one bike to use normally, and one to take to shows and ride on weekend rides. pictures will come soon once i sort out the kick start.

thanks drewpy. The starter has been slow forever, it finally died on me, just completely dead, i think because it was being spun by the engine at one point without me knowing it. I put a spare one in, and same slow crank, just chalked it up to being a 34 year old starter that was wearing out. I'll go and check all the grounds. Battery should be fine, it's almost new, but i can check it again. I should probably put new plugs in, but even those are under 5000 miles old, probably less. Thanks for the tips. I'm stuck on this idea that it's all in the carbs. It's getting better, and i'm starting to learn the bike and what changes do what, which is rewarding.

So i'm still having issues getting the bike to start nicely. I've got brand new carbs (well, cleaned up to perfection), jetting is finally close to right for the pod filters, sync is almost perfect, and it runs really well. Idle is between 1000 and 1500 (my idle stop adjust screw wont' stay put and moves with vibration. need to loctite it.) But it won't start easily. If it's been off for 12 hours or more, even with a topped off battery, choke on or off, i can step on it for 10 minutes or so and nothing. If it's been running in the past few hours then it's easy. A step or two with the run switch in the off position, then a good step with it in Run and it's started. If i give it a quick spray of starting fluid, even just .5 second spray or less to one side, then kick, it starts right up, so my thought is it still can't draw enough fuel through the start circuit to get going after it's been sitting. Any suggestions on things to tweak next? I'm still fine tuning it at this point, so i'm just looking for the one thing i'm missing for this issue. I don't use the electric start for 2 reasons. 1. i have issues with my button grounding, and the starter refuses to disengage, so i've disconnected it. 2. It cranks so slowly on the electric starter it never has a chance of starting anyway.

Keep both. My Buddy's Kawi KZ400 only has one petcock, by design, and it will run out of fuel before the tank is empty since gas can't pass from one side to the other when it gets below a certain level. I think we tested it and there was a good .75 of a gallon that didn't make it to the side with the petcock. Maybe the Yamaha tank is better.