The left one was white. Almost clean looking. There was no oil, no residue on it at all. The piston looked dry as there is no oil in it at all. Does this mean there's no gas going to to? I unscrewed the oil bolt underneath the left piston and oil did seep out of it. The middle cylinder was the best one. Had a little oil, looks like it's firing properly. The right cylinder was completely black and covered with carbon and oil. The ring around the spark plug hole was pretty oily and the spark plug was pretty black. Also the top of the piston seems covered in carbon. I'm gonna post a pic of all this it a little later when I get to a computer.
This is interesting because when it was running the left tail pipe had a decent amount of blue smoke coming out of it. When the bike heated up, the bike really started smoking hard. I'm wondering if it's from the piston or the oil that seeped out is burning on the block? It seemed and maybe in my quick reaction it looked like the smoke was coming from the left cylinder that looked dry from the spark plug hole.
The sudden increase in revs could just be that it was warmed up or it could be an air leak allowing it to run lean. That might explain the white plug on that side.
Oil smoke on the left side is probably oil from the right side coming via the SRIS pipe.
My desktop prediction would be that the left cylinder carb float was adjusted to where it wasnt getting fuel (or enough) and starved. If the idle climbed thats usually an indication of running out of gas on a 2-stroke as it leans out.
Haha Alan! I though I could sprinkle some ferry dust and she would run like new. I bet this guy just had the bike parked and looked at it all day. At least I don't have to do much to make it look nice.
Here's a pic of the plugs in order of cylinders. Left, middle, right.
So I worked on fixing. Lot of lose wires last night and now the left cylinder isn't sparking and either the coil or contact breaker is messed up. The other coils work and throw a decent spark. Should I try switching two of the coils to see if it fires? What's the best way to test the contact breakers?
Close then open the left point set with ignition and Run switch set to On. If you don't get a spark at the left plug, my bet is a bad plug cap or bad plug wire. Try trimming 3mm off the end of the plug wire and swapping to a known good cap.
Cheers,
Mike
ps: if the left was running, it must be wired correctly. On coils, I've had more than a dozen and not had one fail. Its always been 'something else', for me at least!
What a day of detective work...I finally got the bike started. finally. It was was comforting knowing that I figured out the spark issue and now we have an even more interesting issue that i'm thinking has something to do with the carbs? As the bike warmed up the RPM's once again started to raise quickly on their own. Ive attached the videos that progressively show the bike getting worse and worse. It came to a point where I shut the power/and or kill switch to the battery, kept running and raising RPM's. I then shut off the petcock and gas and it STILL kept running and raising the RPM's even more. It was only when i bliped the throttle that the bike shut off. And as if the night couldnt get any better..haha the SRIS valves were all messed up. the right cylinder worked fine, the middle cylinder would let me blow air past in both directions for a second and then would close completely and the left cylinder would only let air pass back into the crank case. Should I just block these off or is it worth repairing? the non existing filters are in good shape though! thanks Coyote for the heads up because they are very fragile. Lastly, as i was looking at the contact breakers and i was turning the camshaft with a wrench, i heard a weird sound in that far left cylinder that i'm not sure what it could be...I have a feeling that something is broken and I dont want to start digging that deep. When cranked, it sounds to the effect of the story of someone dropping a wedding ring down the sink drain. Thats the last video. I appreciate you all checking this out and helping me actually get this awesome bike started! Hopefully soon, i can take it for a ride and appreciate it!
It sounds like it runs quite well. The speeding up does look like lean / air leak to me. Two places worth exploring for that: the intake tubes that sit between the carbs and motor have cracks. They don't often leak, but they might be. The absent gooey boots on the carbs allows air into the slides.
At idle the motor doesn't sound particularly rattly for an old bus. But that clink as you turn it over sounds like a broken something, possibly a ring? can you take off the left pipe and inspect?
Runaway revving didn't look fun at all but you got on top of it.
I think you need to line out the SRIS or eliminate it. One way or the other. Was everything hooked up when it over revved? I agree with Mike about the air leak. Remember, if you pull the lines off, the remaining hole MUST be blocked off. On the crankcase it's easy. Just replace the valves with short bolts and re-use the sealing washers. On the top, there are several ways to block them off. 2 simple ways are to cap them with tight fitting vacuum line caps or use 3 short pieces of SRIS line with plugs in them.
The carb top boots are expensive, but they are necessary. You don't want air going in there either. If I can find the thread, there was a guy that made his own boots by cutting fingers off a rubber blasting glove. It wasn't pretty, but it worked. He just poked a hole in the cut off fingers for the rod and cinched them on with zip ties.
I was born with nothing and still have most of it left.
I would start by cleaning the carbs out and setting float levels.
Then clean out the petcock and fuel lines
Then fit new plugs and set points gap and ignition timing
Then test the kill switch to see if it stops sparks ie make sure it works. The PO may have messed with the wiring and jumped that switch.
Which crankshaft bolt did you use to turn it over - left side or right side? One is through the alternator and the other is on the ignition gear which is made of plastic and breaks if you turn the motor with it.
tz375 wrote:I would start by cleaning the carbs out and setting float levels.
Then clean out the petcock and fuel lines
Then fit new plugs and set points gap and ignition timing
Then test the kill switch to see if it stops sparks ie make sure it works. The PO may have messed with the wiring and jumped that switch.
Which crankshaft bolt did you use to turn it over - left side or right side? One is through the alternator and the other is on the ignition gear which is made of plastic and breaks if you turn the motor with it.
Uhh ohhh. I cranked the one on the points side. Or right side...the sound is very pronounced in the far left cylinder though. Was that the wrong one?
No worries, the 550 points cam is mounted directly on the crank so I'm pretty sure you can use the crank nuts at either end. It's only the 380 that has the nylon intermediate gear that drives the points cam.
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
2017 SV650 AL7 - naked and unashamed
That's good to know. I thought it was both small triples. Learn something every day.
And with clicking on the left side, it's the left side cover I'd remove first and then the head and then the left barrel - going only as far as I need to. If it's blown left side crank seals and a shot rod, all bets are off.
