Help! 1980 xs650

SDcaffinatedXS

SDcaffinatedXS

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Hey guys i have a 1980 xs650 and im having trouble getting her to run. So heres the scoop, the bike has bs34's with heiden tuning needle jet kit with setup to run a free flowing exhaust so the jets that came with it i installed along with the needle installed on the 3rd notch down. Carbs are running xsperformance pod filters. Coil is high output from mikesxs with ngk caps and iridium plugs gapped alittle less than .040. Battery is agm 12v 8amp hour. Carbs set about 4 turns out and exhaust is basically strait pipe. First of all im getting a good spark from the plugs and both are firing at the same time. When i kick start it, it seems like it wants to start but it doesnt want to run. Ill get an occasional poping and a few times it puffed some white smoke and came out from the carbs. I check the plugs theres a little bit of black stuff on it, and since its popping it makes me think its running lean. This is my first build and im almost there, i just want to get her startef so and help or advice will be appreciated. Thanks.
 
Click on "Tech" at the top of the page on this site. The "General XS650 Troubleshooting" section has lots of good info for you to read.

I'm guessing you have carb problems..............are you confident that all passages (and jets) have been cleared?
 
As others have said check your cam chain tension, valve adjustment, timing. Get these right before you start with carbs.
What are the jet sizes you put in? Starting at stock and adjusting the jetting to what your engine likes can be a long process or you might get it the first try.
The stock jets on an 80 are 132.5 mains, 42.5 pilots. With pod filters and open pipes I might try 45 pilot and 137.5 main. The float level needs to be right, 27 mm's.
This www.amckayltd.com/carbguide.pdf is required reading to better understand your carbs. It explains how to clean and tune your carbs. Print it out, read it. Read it till you understand it.
 
Alright ill check it out. Also it was kinda weird when it puffed smoke it only came from 1 carb. When i installed the needle jet kit i cleaned the carbs befor installing them, and a quick question, when i changed out the jets i noticed there was only 1 rubber plug over the pilot jet, i was thinking i lost one since i assumed both carbs would have the rubber plug covering the pilot jet so i made another one and plugged both of them, so are there supposed to be a rubber plug in each carb or no?
 
rubber plug on each pilot passage. I had that problem too. The bike would only start full throttle, full choke. + starter fluid.
took both the carbs back apart, and cleaned the crap outta them. pilot jets plugged prolly
 
alright so im finally home from work. i installed a 145 main jet and 45 idle/pilot jet since thats what the instruction say. the main seem a bit big. im going to try i 135 main jet instead and see how that goes.
 
You need both of those rubber plugs. I will say that 4 turns out on the mix is a little much. That's really pushing the limits of the spring and the screw can back out or turn by itself. I have pods, and Harley exhaust 142.5, but when it was open I ran the 145 and 45 and it worked great.
 
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It doesn't want to start, are you sure you got the choke feed passages in the float bowl clean? They are small, low, and easily clogged. I would have sprayed ether by now but that's me.
By the way thanks for a great run down of your set up!:thumbsup: Half the time we are on page three of posts before we find out it his brother's Sportster we are helping with......
 
Well i just got done cleaning my carbs again. I reset the carb floats to about 27mm. Now all of a sudden im getting no spark. Talk about frustrating.
 
Haha i have plastic floats. Ugh is definately what im feeling right. I just had a spark a second ago but now it gone again. I dont think this bike likes me. :(
 
Check your fuses, shutoff switch by the throttle, connectors and lastly the coil connection. If that fails get the multimeter out and start chasing electrons....
 
If you still have the original 4 position glass fuses:yikes:..................they cause lots of intermittant problems. Replace with automotive blade type fuse holders, and your reliability will increase 200%.
 
Yea i still have the glass fuses. I just bought automotive blade type with holders. I probable replace them tonight and see what happens. Thanks every for your help so far. Keep you guys updated.
 
Alright so i got home from work and i was messing with the bike, i have the clutch case removed and the clutch line disconnected and it was dangling and kinda touching the frame and i turned on the ignition and kinda lightly kicked the kick starter to see if i was getting a spark and i noticed the metal part of the clutch kinda sparking against the frame. So heres the weird part with the ignition on and the clutch line NOT touching the bike when i kick it Doesnt spark. So if i kinda rub the metal part of clutch line against the frame or something the spark plugs will spark with out kicking it. Wtf does that mean????? Im trying to think how that will cause the plugs to spark while totally bypassing engine rotation. I kinda have a feeling somethings wired wrong. Any suggestion?
 
Near certain that you have an issue with ground wiring in the headlight. :doh: Open the headlight and check the black wires. The handle bars are rubber mounted and need to be grounded through a wire. On an 80 the LH switch has a black ground wire that ties to several other black wires in the headlight and those all connect with a black wire in the main harness that grounds to the frame. My advice is inhale slowly and do electrical work for a night or two. Remove and clean all the ground leads you can find. Replace the fuse box with a new blade or glass tube fuse box from the local Radio shack or auto store. It will not hurt to open check and clean every electrical connector you can find. Do it now or do it on the side of the road some night. Just standard old bike stuff!

Odds are with the bike on the center stand turning the bars slowly side to side you will find a strong "center spot" where the handlebars want to be and will actually turn back to that spot. This is bad steering bearings and is possibly related to your ground problem!
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I think one of the first things anyone needs to do when they get a new-to-them bike, especially an old one such as the XS, is go through all the wiring. People always say change the oil, adjust this, check that, but one bad ground can leave you on the side of the road, having no idea what happened. A chain brakes you know it. Engine starts loosing steam you know it. Bad ground......have fun chasing it.
I've mentioned it before that my wiring seemed fine and I had no problems. I went through it after hearing horror stories and found all kinds of messed up stuff. The best was all the dried mud in the harness. I mean packed all around the wires, which in turn made them brittle to the point that the wrapping was the only thing holding them together. gggGary is right, take some time and go through it...all!
 
Here is what i have and do with all the bikes that come in so i know if the electronics are good or not so you don't waist time trying to find a bad ground or bad wire.
I have cheater wires. I made up two different sets of wires for points and for electronic ignition. I unplug what the bike has and only deal with the charging system and spark first. Plug in my wires and check the reg/rec and coil points or Electronic. I pull the plugs hit the starter or kick it and see if i got spark if i do i start motor and check charging system. If alls good i have a good basic start and know that the parts in bike are useable. I have had so many of these harnesses hacked up and spend time trying to figure out what they did. Do the basic first check with a test light and go threw the 12 volts up to the coil. If you have it then back track to the sorce . If its electronic ignition they will give intermittent spark just because of poor ground or its bad. Its tough if you don't have spares to compare it too and you may be over looking something as simple as a faulty ground. I just had a battery drive me crazy . I tightened up ground lights went dim unscrewed it a little lights got bright. I though it was a ground and went over my harness then i swithed battery and all good. Just to see i was not nutz i hooked up test light on battery on bench and tightened ground light went low. NEVER SEEN that before.
 
Hey gggGary does the headlight and handle bars need to be properly grounded in order to start the bike? i was up late last night trying to simplify the wiring, is it possible to just only connect the ignition component and start the bike or do you need to have the head light, tail light and all that stuff hooked up? basically last night i took the whole wiring harness apart, so i can get rid of the wires that i dont need, i kinda tryed to just hook up the essentials that would be required to start the bike just to see if any of my electronics are messed up followed some wiring diagrams and no luck. just going to take it slow and kinda do some trial and error. thanks guys
 

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