71, spark, fuel, no go.

angus67

angus67

Welder's penetrate deeper!!
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hi!! got a friends 71 that hasnt ran in years. he overheated it at 90 mph, and it locked up. he let it cool off. and it started, but smoked, so he gave it a ring job, and honed it, put it back together, and it wouldnt start.
13 years later, he hands it over to me to see what I could do.
cleaned out carbs,(early 38's) new plugs, 95/110 comp. with poormans leak down shown good. cam chain checked valves set at .004"/.006" (thanks 5twins), checked pionts gap. the plug wires looked iffy, so I replaced with some old ones I had from my '80. showed improvement. nice spark on rite side, faint spark on left. battery at 12.56 volts. floatbowls are full of fresh gas. I gave it a new condenser.
turn the key to the first detent, have power to points, give asquirt of either, choke, give half throttle, and start kicking.
got a couple pops, and even a few vrooms, but something isnt rite. could be reg or rec?those are my next guesse. how am I doing trouble shooting? tomorow i'll put in new points
nice bike too. his dad bought it new in 71 with 300 miles.
Photo100215021-vi.jpg

Photo100215011-vi.jpg
 
Since he had the top end all apart and it won't start since, are you sure the advance rod is assembled correctly and not 180° off?
 
how do I check that? would it still try to fire occasionally with the advance rod 180? can I just pull it out, and turn it 180 and lock it back in?
 
after reading a few search threads, im inclind to think the backing plate is off. its locked all the way forward
could someone snap a pic of thier backing plate on a bike that runs?
 
After the wonderful job you did on that 1st bike, this one should be cake. It has nothing to do with the backing plate, it's the cam thingies on the ends of the advance rod. If you don't align them, the timing will be off .....

AdvanceRod.jpg


The locating pins on both sides must face in the same direction, if not your timing will be 180° off.
 
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i notice the advance wieghts dont snap back like they should. could that effect it? going straight advance before it even starts?
 
If you have 200 to spend get a pamco and a new coil and it'll take care of all those problems for good! My 71 would never run consistently well with the points... but the pamco ignition did it up really nice!
 
dont have 200. i cant charge this guy. small stuff, cleaners lube and adjusting things are cheap, and so is labor for a friend. Ide love to convert my '80 to pamco, but then theres that 200$ thing again.
 
Your advance rod appears to be correct. You don't have to check it at TDC, you can check it in any position. If the advance isn't snapping back as it should, you probably need to service the rod (clean and grease). If the ignition is stuck at full advance, it could cause problems like you're having. Remove the disc from the advance side of the rod. Pull the rod out from the points side, the points cam can remain installed. Clean and grease the bushings in the cam ends that the rod turns in. Lightly grease the entire rod length and reinstall. Coating the rod is mostly for corrosion protection. The main source of lube will be from the grease you packed into the outer bushings. Clean and grease the pivot posts for the weights as well.

The top set of points should be connected to the right cylinder coil, the bottom set to the left.
 
i pulled the rod last night, and was greased up, so should be good there. will see if pionts are connented in wrong cylinders in a few. thanx. I will also take a coil out of the advance springs.
 
Mod one spring only to start. That's sometimes enough. You don't want the springs too strong or the advance may not function as it should.
 
i swithced the coils around to no avail. then started looking at the connections, and resoldered were the condenser plugs into the coil with the power feed. all loose. electrical tape is just a bandaid to get you home, people!!
so, a little cleanup, allittle solder, looks good.
i focus in on the points, and figure out wich coil goes were. 5twins says the upper points go to the rite coil, and they do. piont wires comming out of the housing are intact and not shorting.
I had mentiond i was going to put new pionts , on, so I got out the new pionts and compared the 'meat' on the new verses old, and um....yeah. old ones shot.
so, confident with fresh solder, new pionts, topped off battery, turned the key, and choked and started kicking. (the bike, not me).
first kick poped back thru carbs. feeling assuerd the next kik would be golden, I gave it a mighty kick, and ........nothing. kick,kick,kick,kick,nothing.
time for a beer.
 
When you cleaned the carbs, are you sure you cleared the choke jets? If they're plugged, the chokes won't function and the bike will be hard to start when cold.

If you still have a weak spark on that one side, that coil may be bad. You could try switching them side to side and see if the weak spark follows.
 
well, i thought i cleaned it good.
ran for a minute to get it to idle by itself with the choke on. grabbed my screwdriver to adj the idle screws, and it blew the 20 amp fuseand died. this was the original glass fuse, so i wired in a blade 20.
now, when i start it, it revs up, and the fuse pops. could the regulator be be sending a huge spike to the battery blow the fuse?
i'll prolly build the chrysler reg. if thats the case. can i test the reg?
so close, but yet so far
 
so, update.
went and got a fist full of 20 fuses. unfortunately, the package lied to me, and they are 30's. only one was a twenty.
took out the head lite, looked for arc spots,none, hunted all over the wires for bare wires, nothing. tested the regulator as per the original xs1-b service manual, seems good.
ok....put the fuse in, full battery, turn the key, and start kicking. three kicks in, it puts, then the next kick, it started. give a few revs, and the fuse popped.
could the rectfier not be rectifying? the manual is vague on testing it. ive been searching for more specific threads, but am confused.
maybe i'm not useing my multi-meter corectly. for ohms testing i have it set to 20k ohms, with the probes black=ground, red=V(ohm symbol)mA
 

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