Spark then No Spark... within minuites

andrewdell19

andrewdell19

Active Member
Enginedoctor said:
andrewdell i'm at 7000 ft, usually riding upwards of 8 or 9 k, sometimes climbing to 10. If you're at seven, i'd go ONE size leaner on the main jet. the idle you might not even need to change. i'd try using the screw to lean it out. the carb might very well be a mess. rebuild instructions here. you might have to go 2 sizes leaner, but i think that's extreme. the altitude knobs i've only ever seen on a 90. i'm sure there's others with it. if i remember correctly, pull the knob 6500 feet or above, and it leans the main. i don't know how, i haven't been in one. Regardless, if the baseline tuning on the carb is good to 6500 feet (on the 90's anyway) then you might be able to do your tuning with the carb throttle needle/ metering rod. BTW the original 90's and 110's are BEASTS and will climb anything at a crawling speed/


someone has definitely 'hacked' a little bit on this bike. possibly not too bad (can you post an entire bike pic?), but like racerx said, WTF on that ground strap. it seems your previous owner was chasing an electrical gremlin. maybe it was intermittent spark (ha!) i don't know what he would want to ground the cylinder head and intake for… maybe the coil has a bad ground. maybe the ground to the points is bad. maybe it's shorted. this is where electrical stuff gets confusing, but i bet cleaning and gapping the points (or replacing and gapping) will do you a world of good. these bikes are generally very reliable. make sure you have a good connection at the battery connector. the two black wires there must have good contact or you won't get spark. If you hold the wire and it zaps you, you're close at least. if you have a multimeter, check for good ground at the coil, if you can reach in there, and the engine.

let us know where that gets you. i bet the bike will run really well when you sort those issues out.
Click to expand...

Sure what specifically do you want me to focus on for the pics?

The more I think about it and look at the bike, I think the PO use to race it. The headlight is out of it, and so is the tail light. And it looks like it has sticker on it that has number. So I think he use to race it a while back.

That ground strap is is a little bit split in the middle. Would that be causing any ground issues? I would think as long as most of it is in tack it wouldnt cause anything to go wrong if he had it on there for a reason. I have a new points coming, and once I get the flywheel puller I will know for sure if the the ground to points is ok or not.

At the battery, it is a pigtail connector, and as far as I can tell on both sides of that it is good. However, should I clean it out with a little bit of WD40 electrical connector spray?
 
Enginedoctor

Enginedoctor

Well-Known Member
doesn't look terrible… the numbers on the front fender confuse me.

so here's the deal it's a 6v electrical system, but the coil has it's own circuit, so for simplicity, pretend there's no battery. The ground to the coil is completed by the points. sortof. if that makes sense. so the points need a good ground (when closed). when the points open, a current builds up in the coil, then the plug goes spark. For this reason, the points, coil, and engine must all share a 'common' ground. since they're all made of metal (engine, steel section of coil, points, etc) all they have to do is 'touch' each other in a clean union, and then you should have a good ground. if the frame was painted (looks like it may have been) the ground could be broken, but it's unlikely. essentially, half the electrical system is grounded, on all cars and bikes you see everywhere. some exceptions, pretend they don't exist.

let me know if that explanation helps.
 
cormy

cormy

Member
Those of us who have gone through this feel for you..!

My problem was a shorting wire in the stator assembly ( under the flywheel).

Pay close attention to the wiring that is crammed under the flywheel..not a lot of room to work with.
 
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