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

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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!

 

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.

 

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

 

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.

 

... 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.

 

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

 

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!

 

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.

 

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.

 

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.

 

My 2002 is 100% stock and just 6k miles. 1500 miles and 5 years old when purchased. It has always needed choke for a few minutes after starting and has always been near impossible to start first time in spring. I'm unsure if it backfired, but it does now when warming up...I think more than it used to. I've never replaced fuel filter nor air filter which looks like new. All original.
Modifying muffler could make it too lean. Mine is stock.

 

Yours sounds better than mine when cold.

 

Boy, it sounds like you have a sweet bike. When I bought this one I was hoping to take it to pristine factory showroom condition. Then I found out how expensive OEM parts are. Now my goal is to just get it running in pristine showroom stock condition. The SV650 is an incredible bike because of it's incredible motor. That's what I want to experience every evening.

 

Mine runs fine once warmed up. I had stalling problems at stop sign and red lights. Finally got the idle adjustment to turn to speed up the idle a couple years ago.

 

Just thought I'd add. Whilst you are wafting for parts etc do something that a lot of bikers never do put can pay big dividends. Disconnect the Battery and remove and service the Starter motor e.g give it a good clean and fettle.

This is an old thread but the principles are the same,

CX500 GL500 650 Global • View topic - Starter motor servicing

Over time the Starters get tired and neglected but a crappy Starter motor puts more strain on the Battery when activated.



PS
I haven't done mine for a couple of years so tomorrow I will as I am also replacing the original Starter relay

 

Good idea! That is note something I even considered. Yes, the parts are taking more time these days, so I have some spare time. Also, I have a MOFSET RR that I will be installing, I think upon your advise in a post I read (or on your CX500 site). I also ordered the NGK caps.

 

Carbs with enrichment circuits rather than a simple choke plate can be frustrating to diagnose when/if they are malfunctioning. Being that we're on the verge of summer (come ON 'Global Warming'!) if you'd bump up your pilot jets to 17's you really shouldn't need the 'choke' enrichment to start even when cold if the idle mixture screws are adjusted a tad on the rich side. If I were you...for 'diagnostic purposes only' I'd block the enrichment circuits temporarily just to make SURE they're not adding unwanted fuel and see how it gets on. If the choke cable doesn't move smoothly and easily then it for sure might not be opening properly and more importantly it might not be closing completely.

Starting the engine the throttle needs to be closed to apply vacuum to the idle circuits or fuel will not be drawn. When flooded if you open the throttle fully it'll clear out any excess fuel and should start. The electronic ignition systems can make a very high voltage spark but lack the ability to deliver much current so the spark isn't 'hot' so to speak. At the Ford dealership I worked at back in the '90's the management wanted all the cars on the lot moved every other day....to make passers by think that we were selling lots of cars....at least that's what they believed would happen. In reality we mechanics spent a bunch of time pulling fouled plugs and cleaning them with a torch just to get them started. Repeated cold starts without giving time to warm up fouled them after just a few starts in a row without letting them warm up.

Dyna makes BIG coils for the SV1K and I've been happy with the set that's been on my bike for the last 25,000 miles or so. They throw a good spark with a bunch more current than the puny little stock coils can muster. Even with the big coils if the engine doesn't start within a couple cranks it's going to foul the plugs and need WOT to get it to start. Too much fuel can very quickly short out the spark if the plugs get wet...so please try to block the enrichment circuits and see if things don't improve. If it then starts and runs well you'll know for sure that the new choke cables will fix you up.

 

Carbs with enrichment circuits rather than a simple choke plate can be frustrating to diagnose when/if they are malfunctioning. Being that we're on the verge of summer (come ON 'Global Warming'!) if you'd bump up your pilot jets to 17's you really shouldn't need the 'choke' enrichment to start even when cold if the idle mixture screws are adjusted a tad on the rich side. If I were you...for 'diagnostic purposes only' I'd block the enrichment circuits temporarily just to make SURE they're not adding unwanted fuel and see how it gets on. If the choke cable doesn't move smoothly and easily then it for sure might not be opening properly and more importantly it might not be closing completely.

Starting the engine the throttle needs to be closed to apply vacuum to the idle circuits or fuel will not be drawn. When flooded if you open the throttle fully it'll clear out any excess fuel and should start. The electronic ignition systems can make a very high voltage spark but lack the ability to deliver much current so the spark isn't 'hot' so to speak. At the Ford dealership I worked at back in the '90's the management wanted all the cars on the lot moved every other day....to make passers by think that we were selling lots of cars....at least that's what they believed would happen. In reality we mechanics spent a bunch of time pulling fouled plugs and cleaning them with a torch just to get them started. Repeated cold starts without giving time to warm up fouled them after just a few starts in a row without letting them warm up.

Dyna makes BIG coils for the SV1K and I've been happy with the set that's been on my bike for the last 25,000 miles or so. They throw a good spark with a bunch more current than the puny little stock coils can muster. Even with the big coils if the engine doesn't start within a couple cranks it's going to foul the plugs and need WOT to get it to start. Too much fuel can very quickly short out the spark if the plugs get wet...so please try to block the enrichment circuits and see if things don't improve. If it then starts and runs well you'll know for sure that the new choke cables will fix you up.

This is good information Rob. I will certainly look into those coils. When you suggest blocking off the enrichment circuits do you mean simply removing the cable and reinstalling the plungers? How do I block this off? And, yes, I need to bump up the stock pilots to 17s.

 

Just got an email from MotoSport. The choke cable and plungers are on backorder. Damn. I'll check other suppliers.

 

i ordered a front intake manifold tuesday from motorsport. i just heard it's on back order. Maybe i should of went thru partzilla, but they usually take a couple days to ship it out the door. I'd be interested if your able to get it sooner than later. I'm going to try rtv sealant to get it going if it's not totally blown out. I ran it up to a hundred in forth gear and as it was winding down i blipped the throttle downshifting and it backfired

 

I just reordered from Babbitts Suzuli Part House. Supposed to get here between 5/5 and 5/12. We'll see.

 

Just for grins I drained the tank yesterday and replaced the gas with non-ethanol gas and about 4 ounces of Seafoam. Started (on choke), warmed up, release choke, rode up and down the street with it bogging and popping. I was hoping to run the new gas through the carbs and to blow it out. Within 2 miles the bike slowly died. Later in the evening I started it up, on choke, and the revs went to about 3,500, held there for about 30 seconds, then the motor abruptly died. Would not start on choke or off.

 

Check to see if the Fuel filler cap venting is OK. If the filler cap breather system becomes blocked it will prevent fuel flow by causing a partial vacuum in the tank.

 

Yes....please make sure your tank vent is functional...if it's blocked the engine will slowly pull a vacuum on the tank and eventually die. When it's running and starts to misbehave...pop the filler cap and see if anything good happens.

To block the enrichment circuits first pull one of the choke plungers out of the carburetor and look at it closely. The main body has a seal surrounding the smaller diameter plunger and the whole thing is pushed in and seated by a spring. Make sure that seal is there and in good shape because that's what shuts off the enrichment flow. The 'needle' so to speak the seal surrounds then modulates the flow by being lifted up and out of the bore. This plunger must move smoothly and easily...as in the videos listed above clean and make sure the spring pressure is able to push it down and seat it securely. Take off the cable then reinstall the plunger assembly. This 'should' positively stop the choke from coming on. Hoping you then can reliably start and run the bike until your new choke cables arrive.

 

Recall, I drained the fuel, added a half bottle of Seafoam, and refilled with non-ethanol two days ago? After that I fired it up and it ran for about five minutes, then died. In another post I read of the Seafoam needing some time to work. So, out of curiosity, last night I tried starting it, and it fired up. I then took the bike for the longest ride I've had since all of these problems began.

In all, I rode for about 12 miles, and the bike ran beautifully. I am quite surprised, but pleased. Could it be that my primary problem all along was bad gas? I'm cautiously optimistic. We are expecting rain for the next four days in south Louisiana, so I won't be riding soon. But I'm hoping this lasts.

Thanks everybody for your sage advice.

Meantime, I plan to rebuild my extra carb set, rebuild my existing choke mechanism, install a new R/R, and remove whatever is rattling in my gas tank. Oh yea, when I removed my gas tank I heard something hard (like steel) rattling in the tank. Sounds like it's a screw or something, and I could not get it out. Last night when I was riding, at certain RPMs it would rattle like crazy. It was quite annoying, but I was in bliss with my running motorcycle. I will try to fish it out this morning with an extension magnet. Cheers!

 

Just if anyone with a crappy/non running Gen1 is following this, I continued this saga here:

Good Saturday Gone Bad---long post

Hang in there. In this thread I (hopefully) solved the problem.