Howdy everyone! I've been lurking for a little while now, mostly trying to solve issues on my own. I picked up a 1979 Cb650 in pretty decent shape about a month and a half ago now. I bought it with the impression that it didn't need a ton of work, just some focus on some idling issues. Definitely not the case as I sit here now.
To provide some background, when I bought the bike, cylinders 1 and 4 weren't firing, and the bike wouldn't idle on it's own, even with full choke. I did a basic carb clean and replaced the spark plugs. Cylinder 1 popped back into life and the bike would idle on it's own after a few minutes of warming up. God knows what magic the PO did when he started the bike on two cylinders when showing me, but I still have a hell of a time getting the thing to start regularly sometimes with three.
What's killing me, and what almost led to me putting a 'free' tag on this bike yesterday is that I still have no clue if the timing is set remotely right, the carbs leak even after new gaskets, this bike has run on at most 3 cylinders since I bought it, and the LED turn signals are a purchase I'm beginning to regret.
So, I'll lay out the main issues that have been plaguing me. Help with any/all is profoundly appreciated!!
---#1:Carbs. I'm a professional bicycle mechanic, so I have a pretty solid mechanical aptitude and I understand the fundamentals of carbs, I guess. I've got the PD50A Keihin carbs on this bike. I replaced floats, and needle valves, made sure jets were clear. I picked up a float bowl gasket kit from Dime City and the gaskets are significantly smaller than the old ones. Shape and whatnot matches, and supposedly these are for this bike, but I can't help but be wary of smaller gaskets. The float bowl in carb #1 leaks still.
---#2: Timing. Since this bike isn't running well enough for dynamic timing, I need to set it statically. WHAT MARK EXACTLY DO I SET THE TIMING TO??? I understand 1-4, but there's a hash with a 'T', an 'I', two hashes with an 'F', and an 's'. I've poured over forums, manuals, and common sense yet all seem to come short with an exact mark. This is an exact thing, timing, so why does it seem so difficult to find an exact mark? Reason #1 why I grab that extra beer right here...
---#3: Three cylinders. I've checked electrics, replaced bad ignition coils, spark plugs... I'm getting spark, float bowls all have fuel so assumably the cylinders are getting fuel. I have had each cylinder firing at one point or another, but never all 4 at once. It's killing me.
---#4: LED turn signals... Admittedly a desperate weak point in my abilities is electrics. Normally I'm known for blowing fuses, circuit breakers, and creating fires. So far I'm only down a handful of 10A fuses. I replaced all my turn signals with LED signals, power differentials unbeknownst to me. If I had known I would have kept the old stock signals... SO, I wired everything as per the wiring diagram, pretty stoked on even that. Now my front signals are always on, the rear are always off. When I hit the turn signal switch, the front light on that side will turn off, the rear will turn on. They won't flash. I picked up a number of electronic flasher units at the auto store, but still nothing. Do I need a motorcycle specific one that doesn't have a minimum draw? Do I need resistors? I know I need a beer. Do I need to wire things in some non-stock way?
I understand I have a lot of independent issues going on here, but I figured one big post is better than 4 small ones. That said, I'm on my knees here, appealing to your collective knowledge. Thank you in advance!
p.s. here's a picture of the machine! My plans are sort of scrambler-ish/brat
