[Geo Smith]

Just to put a thought in your mind, if the bike is misfiring that means the fuel is not being ignited, so that air/fuel charge will be expelled on the next exhaust stroke. It will smell like fuel. That doesn't necessarily mean it has a AFR issue (like rich or lean) just that there is fuel not being burned.

That's a good point GC. Meaning it's not necessarily ignition. But the smell of unburnt fuel is all the time, not just when it misfires. Once it starts misfiring, it's cooked. It's going to die soon, and it is not going to fire up again unless I change the oil, or clean the carbs, or change the plugs, or some other shit. Maybe it will restart if I add air to the tires. Who knows.

 

[Geo Smith]

Okay, I just tried starting it. It would not start. Simply spinning the engine with a few fires here and there. For grins I shot some starting fluid in the airbox (filter removed), and the bike started. It ran very roughly, SV325ish, but it started. Scared the crap out of me because it's loud as hell without the filter in. Nevertheless, this is the first time I was able to start it in all three times it crapped out, without changing something (oil, plugs, carb, etc.).

If anything, it is progress. This seems to narrow it down to a fuel, rather than ignition issue. Thanks golden chicken, straticus, TeeRiver, Mad8V, JayV, and all others for your advice.

Oh shit! I just realized the rear plug is still out. I took it out this morning to look at it, and did not put it back in. I just started my f--king bike without the rear plug in. No wonder it was so f--king loud. No wonder it sounded like it was missing a cylinder. This is hilarious, but sad. Something tells me I should leave mechanic-ing to the professionals.

Anyway, I think it is progress. I've got to get back to work. But, this evening after my wife and I walk the dogs, and open a bottle of wine, I'm going to see if it will start again with the starting fluid (and with the rear spark plug installed). I'll call it drunk wrenching.

 

[golden chicken]

Something tells me I should leave mechanic-ing to the professionals.

As a professional, let me be the first to admit stuff like that happens all the time. We just fix it and move on after we realize we screwed up.

 

[Straticus]

We have a saying in the Aircraft Painting game.

" It's not how you F**K up, it's how good you are at Un-F**king up ;-)

 

[Geo Smith]

I started it last night, with the help of some starting fluid squirted into the carbs. It popped and sputtered, and while it was warming up on choke the front carb would pop, releasing a puff of vapor. It did these single, distinctive pops about every five seconds. And it was only the front carb. After it had warmed I released the choke and the popping pattern stopped. But the motor still ran very rough. Here's what it sounded like.

The pattern that it has followed is it will run like this for a minute or two, then it will start loosing a cylinder, then it dies. Then it will not start, except for this time where I was able to get it started with starting fluid.

 

[Straticus]

Something we've not mentioned are the, "Choke Plungers". These are a known cause of this kind of problem especially the front one. I had to left hand drill out the JIS screw in mine as it had become seized and then clear corrosion and debris off the mechanism so they both operated correctly.

How to check choke plungers? - SV650.org - SV650 & Gladius 650 Forum

How to check choke plungers? SV Talk, Tuning & Tweaking

forums.sv650.org

Different bike but same principle,

 

[Geo Smith]

Something we've not mentioned are the, "Choke Plungers". These are a known cause of this kind of problem especially the front one. I had to left hand drill out the JIS screw in mine as it had become seized and then clear corrosion and debris off the mechanism so they both operated correctly.

How to check choke plungers? - SV650.org - SV650 & Gladius 650 Forum

How to check choke plungers? SV Talk, Tuning & Tweaking

forums.sv650.org

Different bike but same principle,

Aha! That is very interesting. The choke cable is one of the things I have on my list to replace. Here is a pic of the POS.

The cable and the slides are one thing I paid little attention to when I had it apart. The choke works, but it is very hard to actuate. Maybe one of them is sticking. If so, it runs rich, fouls the plugs, then does not start. I hope it is my solution. Thank you!

 

[Straticus]

I use this down all my cables and on gear/clutch/brake levers and joints,

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way better than crappy WD40 that many use. Also if I'm lazy a light spray on the drive chain does a decent lube job as I've used it for years on my Bicycle chain/s. I believe in PTFE as lube as I do in Molybdenum DiSulphide products.

I also use it on/in external locks/padlocks and door hinges etc and as a re-water proofer for my Riding Gloves/boots and jacket but do that outside as it's smell can be pervasive until it dissipates.

 

[Geo Smith]

I wanted to wrap my arms around the pattern the bike follows, runs...dies...fix something...runs. So I put together a timeline to get things straight in my head.

The pattern is clear. But why would it start running fine after I changed the oil on 4/18/21? Very strange. Straticus raised a very good point. It may be one of the chokes sticking and making it run rich. Logically, this could foul a plug, and make the bike run like crap. Considering the bike is running right now (but like crap), this afternoon I'm going to change the plugs again. If it runs great, it will be a strong clue that this is all caused by plugs fouling, and that it's probably in the carbs.

 

[Straticus]

If at all possible get a 2nd pair of eyes on it from some one you know who knows Motorcycles. Sometimes it can be something obvious that we miss. As I'm sure you appreciate it's hard to help sometimes from a remote location

 

[Geo Smith]

I use this down all my cables and on gear/clutch/brake levers and joints,

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way better than crappy WD40 that many use. Also if I'm lazy a light spray on the drive chain does a decent lube job as I've used it for years on my Bicycle chain/s. I believe in PTFE as lube as I do in Molybdenum DiSulphide products.

I also use it on/in external locks/padlocks and door hinges etc and as a re-water proofer for my Riding Gloves/boots and jacket but do that outside as it's smell can be pervasive until it dissipates.

The one thing I did with the choke cable when I had it off was lube it. The stuff I used was Protect All Cable Life.
https://www.amazon.com/Protect-All-25006-Lubricant-Vehicles/dp/B0022UOYTE
But, as you can see from the pic, the cable was a piece of shit, being held together by zip ties. I will order a new cable and some of the Super Lube you recommend. Looks like good stuff.

 

[Straticus]

The one thing I did with the choke cable when I had it off was lube it. The stuff I used was Protect All Cable Life.
https://www.amazon.com/Protect-All-25006-Lubricant-Vehicles/dp/B0022UOYTE
But, as you can see from the pic, the cable was a piece of shit, being held together by zip ties. I will order a new cable and some of the Super Lube you recommend. Looks like good stuff.

It's all pretty much the same PTFE lube and we are lucky here as a local small Supermarket chain do a big can at a good price,

https://www.wilko.com/en-uk/gt85-lubricant-oil-spray-400ml/p/0337625

Way too many uses not to have in the toolkit

 

[Geo Smith]

Straticus, you got me with the Molybdenum DiSulphide products. I cannot even pronounce this, much less understand what they are. I'll stick with the Super Lube you recommended. Thanks for the input!

 

[TeeRiver]

... I'm going to change the plugs again. If it runs great, it will be a strong clue that this is all caused by plugs fouling.

That would be the first step I would take. It will tell you for sure if fouled plugs are the cause or not.

The next step of course would be to find out why fouled. Fouled plugs fit the symptoms well but at the same time I am skeptical; never really seen this happen on 10 years of SVR tech posts. It is an easy test though.

A problem with the plug caps or connection between the plug caps and high tension leads is more common. It can cause intermittent failure. I know you already looked at this a bit but maybe try remove the plug caps, cut 1/4" off the lead and screw back tight.

A little story if I may. In 1972 I had a Yamaha 100. This beloved pos used to foul the plug on a regular basis. The very first day we had it the plug fouled and I thought the bike was ruined. Mr. Rose from across the street came over (he had a DT250 and his sons had a CT175 and Mini Enduro). He had lots of experience with fouled plugs and knew right away what to do. He changed the plug, the bike fired right up(!), and he instantly became a super hero genius in my mind. I will never forget that.

 

[nicks-sv]

if the choke cable is cracked your front cylinder is probably not getting any use from it. when you pull the choke lever the cable flexs and does not pull the plunger on the front cylinder. a new cable would be a good idea. i put a worm clamp around where the cable splits to keep it from cracking again.

 

[Geo Smith]

That would be the first step I would take. It will tell you for sure if fouled plugs are the cause or not.

The next step of course would be to find out why fouled. Fouled plugs fit the symptoms well but at the same time I am skeptical; never really seen this happen on 10 years of SVR tech posts. It is an easy test though.

A problem with the plug caps or connection between the plug caps and high tension leads is more common. It can cause intermittent failure. I know you already looked at this a bit but maybe try remove the plug caps, cut 1/4" off the lead and screw back tight.

A little story if I may. In 1972 I had a Yamaha 100. This beloved pos used to foul the plug on a regular basis. The very first day we had it the plug fouled and I thought the bike was ruined. Mr. Rose from across the street came over (he had a DT250 and his sons had a CT175 and Mini Enduro). He had lots of experience with fouled plugs and knew right away what to do. He changed the plug, the bike fired right up(!), and he instantly became a super hero genius in my mind. I will never forget that.

Yes, those old 2-strokes loved to foul plugs. I remember keeping the revs up in the pits simply to prevent fouling. When I had it apart last weekend for the carb cleaning I removed both caps and clipped a small piece of wire for a fresh connection to the caps. I did the same for the ends that went into the coils, just to be safe.

 

[Geo Smith]

if the choke cable is cracked your front cylinder is probably not getting any use from it. when you pull the choke lever the cable flexs and does not pull the plunger on the front cylinder. a new cable would be a good idea. i put a worm clamp around where the cable splits to keep it from cracking again.

I ordered a new choke cable yesterday. It has always felt very hard to pull, and the existing cable was held together at the Y where the two cables join by some zip ties. I tried spraying lube in it, but it did not help. But, if what you are saying about the front cable is true, would it not actuate at all? Therefore, it would not cause a rich mixture. I assumed a fouled plug would be caused by an overly rich mixture.

 

[nicks-sv]

the cable bends and the choke plunger doesn't get pulled. so it's lean until the motor warms then the front cylinder kicks in. check all the vacumn caps they may look good but be cracked.

 

[Geo Smith]

Replaced the plugs last night to see if it would start with fresh plugs. Alas, it started right up on the first turnover. As you can see in the video, it is bogging a bit on hard throttle, and backfiring, but the wonderful thing is it started. Before, it would not start. This tells me the plugs must have been fouled, which leads me to believe a rich mixture is causing it (a very rich mixture).

When I started it, the exhaust smelled heavily like unburned fuel (again). This has been the case ever since I bought the bike. Straticus and nicks-sv suggested it may be a faulty choke cable, so I ordered one yesterday (including new sliders). TeeRiver suggested the connection between the spark plug caps and wires may be an issue, so I will order new caps and wires this morning. Maybe the popping and backfiring is being caused by one of the choke cables being stuck in the actuated position as shown earlier in Straticus' video.

I'm just learning this youtube stuff. For some reason, youtube put a music background in my video. I don't need this crap, but I don't know how to get rid of the music. If someone knows, praytell.

So, it looks like I am finally narrowing down to some specific causes. I don't want to get cocky. From my readings, the SV gods can be humbling. I am on hold until the choke cable, plug wires and caps come in. Meantime, I am going to fiddle with the choke cable and sliders to see if I can free them up. Also, I have an extra carb set the PO gave me. So I will start rebuilding them. This next rebuild should go much quicker than the first. Funny how that is. Last night's plug change took all of 5 minutes. I'm getting pretty good. DON'T GET COCKY.

 

[Geo Smith]

the cable bends and the choke plunger doesn't get pulled. so it's lean until the motor warms then the front cylinder kicks in. check all the vacumn caps they may look good but be cracked.

Good point. Now that it is running I can spray around the vacuum connections for leaks.