Help with ignition troubleshooting

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hobbes28

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I am working on my 77 xs650, trying to get it running and have come to the point where I have ordered the next round of parts and thought I would make sure that I am not barking up the wrong tree. First I'll give you guys the information on where I am and see if I am making the right conclusions. I'm having to learn this all as I go so there is no telling where my mind pulls ideas from.

I got the bike from a friend and it had sat with gas in the tank for 2-3 years. There was rust in the tank and the carbs were seized. I pulled the tank and carbs and blasted the tank and coated it. I replaced the battery and spark plugs and air filters and tried to keep all of that as authentic as I can. I replaced the oil filters and did a good check up of everything that I have read in the manual as things that fail. I replaced the gaskets on the side covers. I am about to get the new petcocks for the tank and have just made a temporary gas box to supply fuel while I work on getting it running. I have adjusted the valves. The starter turns the motor and it acts like it wants to crank but there isn't ever any fire. Every once and a while, it will backfire through the exhaust. The first thing I thought was timing. I checked the gap on the points and the condition and they seemed good. Still no start so I went back to the carbs thinking it was something I had done. When I have the plug out and grounded I get some spark but wasn't really watching to see the timing. I can smell gas on the plugs but it isn't as strong as I'm used to from working on cars. They aren't sopping wet but definitely smell of fuel. Then again, I am in the garage and most things smell like fuel as far as I'm concerned. On a hunch, I decided to test the points to see if the timing was just way off or if there was something else I was missing. I hooked up my multimeter to the points and it looks like I am getting a charge for spark through about 80% of the rotation. It starts reading 14.3 when the F line is around 180 degrees away and stays at that voltage until about 1.5 inches after it passes. It does this on both sides. After this discovery, I tested to see what the voltage was at the plug and it tells the same story: the spark plug is charged for long enough to make the spark plug spark randomly. Now, this is all just my assumption because I don't really know how all this works, just what I read in books. I'm a machinist by trade so this is a whole new level of troubleshooting for me. :)

On the way here on Wednesday, I have two new points, two new ignitions, new wires, new boots, new condenser pack and new lead wires just in case they are shorting out the whole system. The advancing side looks to be in good order from what I can tell.

I guess the question through all of this garble is: Is this the appropriate train of thought or is there something else that I am missing? The bike was very well taken care of until the owner bought a new bike and let this one sit for too long. I would just like to get it running without replacing all of the parts I don't need to.

Thanks
 
Two sets of points, good.
Two ignitions ?
New wires, good.
New Boots? plug caps?
New condenser pack, good.
New lead wires? Wires from harness to points? Good.
Once you set the points gap you need to check the timing.
Your Manual explians the how to.
If your old points are dirty, even the oil on the feeler gauge is enough to keep things from working. Get some electrical contact cleaner and plain white paper, like business cards are made of.
Hold the points open, spray liberally. Now dampen a piece of the paper with the cleaner, insert into the points, close the points, draw the paper out, repeat the paper part till it comes out clean.
Leo
 
Whew!
I meant to write coils, I think?
Whew!
Plug caps if those are the rubber things that go over the top of the plug. (terminology isn't my strong suit)
Whew!
Yes, those are the ones, Whew!

I figured I would have to buck up and buy the timing light this time. On the rotor for my suburban, I could just twist it while it ran and listen for the spark jumping to time it right. Don't figure I could get out that easy here. I have been reading and learning as much as I can from the manual in the down time while I wait for new parts to come in the mail but still spend a lot of time feeling like I am just taking a huge guess when I go to buy replacement parts.

I cleaned out my points first because I read somewhere on here that dirty points can cause all types of problems but it didn't change any once they were clean. When my new stuff gets here, I will pull the rod and clean everything in the whole system, just in case. Hopefully, this is the last part before I can get this thing on the road and find out just how much more it's going to take to get moving up the road.

Thank you for the help!!
Aubrey
 
Plug caps are the things that attach to the plug wires and hook to the plugs. The ones most commonly used on the XS650 are a Phenolic body with rubber ends to help seall them to the wire and plug. On the points the non resister type are reccomended.
On the electronic ignitions a 5k ohm cap is reccomended.
New coils is a good idea too. The stock points coils are a 10kv output. The plugs take around 6-8 kv to fire. If your voltage to the coils gets much below 13 volts the output drops of and the plugs don't fire as well.
Your old coils have lost some of the output just because they are old.
Upgrading to hotter coils will improve running.
I have upgraded to a Pamco, just because points are more maintainance intensive. I also run a very hot coil, The green monster, output of over 75kv. Using this coil I can open the plug gap to get a bigger longer lasting spark.
This improves performance from starting, idle and all the way to WOT.
On yours putting in all the new parts and setting the gaps and timing the points will give you a definite improvement.
On reading the book, that's good but once you get your hands into the task the understanding will come to you.
Good luck.
Leo
 
Hey, I have the same problem as you man, and I'm sorry I don't mean to hijack any thread at all. I had rebuilt my carbs, replaced the pionts, new sparks. I did not replace brushes or coil. I am pretty new to all of this, I have no background in mechanics so I am here lurking a lot of the time. I got my bike running only because my friend was gaping the points by eye mind you, while I was kicking it. It started! He stated that I had to time it because it was backfiring even when it ran for a brief period of time, so I turned it off and tried to gap it appropriately and what do you know it didn't fire. I'm switching over to pamco... Anyways sorry for the rant, but I am on the same boat, rusted tank and what not.
 
Those are the ones I got. I wondered what the difference was and just took a guess. I won't plan on being that lucky again. My coils are putting out about 3kv average with some spikes over 7kv but pretty sporadically. I just started ordering all new everything because the lag time for shipping is killing me when I find I need more than I got.

When I first started this project and couldn't get the thing to fire because my floats were stuck and the jets clogged, I got so pissed off that I was just ready to quit and walk away, which I never do. It was crazy frustrating to not know how something worked so that I could fix it compounded with not even knowing how to find out what was wrong. There was a chemistry professor I had back in the day that used to beat the three things you need to have a fire, fuel, air and an ignition source. He said that at least seven times a day and could relate it to anything. Those are the things that have gotten me to this place. I've worked out two of the three and this should be the last (I hope).

I think I'll be switching to a Pamco some time in the near future. I have the budget of a father of seven kids because, well, I'm the father of seven kids. This year I want to get it running. Later on down the road, I want to chop it up some and make it a bit more custom. I would say over the winter but those seem to only last a week or so lately around here. :)

No worries about hijacking the thread. It's how ideas come about. Maybe we can even bounce ideas and issues off each other since we're starting with the same foundation.

Thanks everyone for your input.
 
I think my carbs were working fine... But I wasn't sure, I checked compression too but I mean when I checked it, it was from kickstart so I had to give it a few kicks to see. Again new to everything. I had a friend that was helping me, and he's used to working on harley's so he gave up after two sessions. Now everything is going to be all on me. So I am hoping the electrical ignition gets the bike going. I bought the bike from this grumpy old guy who said he never heard it start.
Here's a video of the first time running, you can hear it backfire a lot. At least I know it runs so it's all about diagnosing things here and there and spending money..

I hope yours starts, it's always a good feeling hearing it run. Good luck!
 
Both you guys need to learn how to properly set your timing. Do that and I think both bikes will run. I guess what you don't realize is that when you change the points gap, you change the timing. Any gap adjustment should be followed by a timing check and adjustment if needed. The Pamco is a nice upgrade but that needs to be timed when installed too. If you can't set the timing now, how are you going to set it later with the Pamco? You say you don't want to spend money needlessly because the budget is tight yet you're ready to drop hundreds on new parts, half of which you probably don't even need. The knowledge you need is here and all over the internet - and it's free. Read this over and maybe you'll learn enough to time those bikes. At the very least, you'll get a better understanding of which adjustment does what when trying to set the timing .....

http://xs650temp.proboards.com/index.cgi?board=ID&action=display&thread=7984
 
Pay attention to what 5Twins said. Before you buy anything take the time to learn how a Kettering Ignition works. Your xs650 actually came with 2 complete ignitions to fire the engine. 2 sets of points, 2 condensers and 2 coils. The 2 sets of points are mounted on a single plate, in a relationship to each other. They are operated by a single points cam and in turn fire the coils, generating the spark. Point gap, dwell and timing are all interrelated. Not trying to be harsh here but if your way of timing the Suburban was twisting the distributor
you better go back to basic practices 101. BTW original Yamaha coils, for bikes with points, are notorious for being weak.
 
Not being harsh at all, I haven't bought anything. I will go and do more reading for sure, I pretty appreciative of the information, found some more stuff too. I'm a visual learner so I have been trying to find some visual or videos too, the manual that I printed is a bit dark but thanks guys
 
That wasn't harsh at all. That's what I have been doing, getting back to the basics. The suburban was very forgiving and permitted me to make adjustments to my timing without having to get a timing light nor did it have as many components that made so much of a difference to how it runs. I surely don't expect to just twist on the point plate and get it timed perfectly at all. My original post here was just that "oh crap" moment when I realize I just bought a bunch of stuff without being perfectly clear if I needed all of them. I checked and rechecked all of my multimeter readings and even checked one more time after I posted the original time to make sure my readings were off from what it says on the guide here and in the manual. I am excited to learn how to fine tune the timing and sync the carbs and adjust them because that is the stuff I can really get perfectionist with. I just need it to light up the gas in my cylinder with some sort of regularity before I can get started.

cobrasneverdie, I went round and round about buying a repair manual for this bike and finally bucked up and had one printed from the yamahapubs site for $96 about two days after joining this forum. The only regret I have is waiting so long to actually buy one. That thing has more information than I even know what to do with.

Thanks again for everyone's help.
 
If you have a multimeter and really can't afford a timing light, there is a way to set the timing using the meter. It's called static setting (meaning engine not running) and it will be very close, close enough to get you running. This is for engines with points, not solid state ignitions. This really can be done with nothing more than a 12volt bulb and a pigtail. You have to understand the system but it can be done.
 
Purplezinger - interesting I'll look into this, imnot ileterate with tool, but somewhat when it comes to engines and electrical. Or I guess the whole aspect of bikes haha but I want to learn and this is good.
 
Purplezinger said:
If you have a multimeter and really can't afford a timing light, there is a way to set the timing using the meter. It's called static setting (meaning engine not running) and it will be very close, close enough to get you running. This is for engines with points, not solid state ignitions. This really can be done with nothing more than a 12volt bulb and a pigtail. You have to understand the system but it can be done.
Click to expand...

ok so I poked around and this is what I'm trying to figure out, help me out if I am wrong



06.jpg

i know it's not an xs650, but it shows how to do the static timing. Ok so with that said, and looking at the points, to adjust the right cylinder this is marked "R" on the plate, does this mean the big screw top left and bottom right? So the left cylinder is adjusted by those two smaller screws in the middle (kind of)?
 
Check the adjustment of the cam chain before doing any ignition adjustments.
Ignition adjustments:
Check and adjust the point gap first. This is done with the points rubbing block setting on the highest spot of the points cam. .012" to .018" is ok with .016" preferred. Do this with each set of points. Be aware that point gap is related to dwell and to timing. Once this is done, set the timing of the right cylinder (gray wire). The right side points are mounted directly to the base plate. The base plate is held in place by 2 large screws at the outer rim. Located at 11:00 and 5:00. Adjust the baseplate for timing the right cylinder.
Now set the timing of the left cylinder(orange wire). Note, the left cylinder points are mounted to a subplate that is in turn mounted to the baseplate. The sub plate is mounted with screws that will allow adjustment separate from the baseplate.
Make any timing adjustments to the left cylinder at this subplate only. Do not disturb the baseplate when adjusting the left cylinder.
With careful observation you can determine how these all relate to each other.
 

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