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Suzuki Resurrection Fail

Joined
Apr 23, 2020
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Location
Cedar Park, Texas, USA
I think there's a huge difference in quality between my two motorcycles that I'm having a hard time putting my finger on. I wonder how much of it is "nature" and how much is "nurture".

I got over the last big flub on my '92 GS500 and got it running day before yesterday, took it for a test ride yesterday. It was back to its old tricks, meaning I will have to pull the carbs off again which is just a frustrating job so I avoid it. I'm sure I can get that sorted as long as I get over my mental block against doing the work. It just is so much harder than it has to be due mostly to the fuel line/petcock routing and the airbox dimensions.

So while it ran pretty OK besides not idling properly on my test ride, once I got it home a new, old issue popped back up. The starter. There's a short between the bars on the commutator, it's done this before. I think due to simple age, whatever insulation was once there between the commutator bars has degraded or disappeared in spots and now as the brushes and commutator wear a fine dust of carbon and copper finds its way between some of the commutator bars and causes the starter to short in some positions. I've fixed this before by cleaning the commutator but I think this time it's going to take a new starter.

And that's the thing. With my old GS500, it seems like no matter how many things I fix, something new breaks. I just can't get over the hump. If this was a 50 year old bike with 80K miles on it that had been stored outdoors for two decades to rot then I would understand. But it's not! Sure, it's nearly 30 years old but it only has 24K on it and less than 3K since a top end rebuild. No signs of ever being neglected like rust or rotting parts anywhere. It's been garaged its whole life, obviously, and certainly in the years I've owned it. And I have sifted through the thing either fixing everything broken or worn I find or in many cases upgrading to a more reliable part. But this is supposed to be a reliable Japanese motorcycle, like the Honda Civic of motorcycles.

On the other hand, my 2012 Triumph Bonneville has almost 14K miles on it, 8K or so of which I have put on it myself. But it is basically in nearly mint, brand new condition, even after I wrecked it and had to rebuild a big part of it. But it doesn't have any signs of early degradation of anything. I think the thing will probably go at least 50K before it needs any serious service, maybe twice that!

Maybe it's three decades of "cheap bike" ownership policy... when stuff breaks, the cheapest fix is applied. Or maybe it's "cheap bike" manufacturing policy... when it was built, the cheapest parts were used. Maybe the Triumph is just better not only because it's made of higher quality parts, higher quality design, but also because in its shorter lifetime it was treated better by its owner.

It's mystifying since my old Suzuki was completely designed and manufactured in Japan by a mature motorcycle company with a long history of making durable, high quality products. My Triumph was designed in England by a young reborn company whose heritage was not one of reliable or durable stuff, and then manufactured in Thailand. We're supposed to think building a motorcycle in Thailand makes it substandard to those made in Japan, or designing them in England makes them quirky love/hate bikes while the Japanese in the 90s were known for designing exacting, conservative, and reliable stuff. But this is not true.

I feel like at 24K miles and 29 years of age every single part on my Suzuki that I have not replaced in the past five years is at the end of its service life. That's just a sad commentary on the quality of this thing. The starter in a Suzuki should last longer than 24K miles. It should last 4x that long. The carbs should not require you pull them and clean them thoroughly twice a year in order to keep it running. This bike is not nearly cool enough to be a hobby. It's supposed to be a reliable backup to my temperamental British bike. It's not working out that way.
 
Do you have a good fuel filter on the fuel feed to the carbs? Don't know why the starter is having issues. I have an '03 Vstrom that has been dead rock reliable. I am sure the wiring is nearing the end of its life somewhere in the harness but she still starts first tap and runs great. Fuel injection though, no carbs.
 
No fuel filter. It's not recommended to use a fuel filter with these, it tends to impede fuel flow and cause fuel starvation.

I do think half of my issues are carbs. I will never own another carbureted motorcycle. It's not just fuel compatibility, but there are just 1000 things that have to be perfect with carbs while FI has just far fewer components that require maintenance or will degrade. I know a lot of [mostly old...] folks fear any electronics, but the reality is it is way simpler to run EFI. Tuning is easier and more predictable, and you don't have to remove any parts except the seat!

It just mystifies me how a V-Strom or SV650 can be so rock solid and my GS500 can be such an unreliable clunker.
 
I think parts on your Suzuki have trouble lasting 29yrs and not so much the mileage. My 2005 Gixxer600 track bunny sits in the corner of my garage and the plastic parts on it just slowly but surely rot away. Metal parts survive better, as long as corrosion is kept at bay. I have plastic wheels on the rolling tool chests in my garage that just spontaneously fall apart into a thousand pieces - just due to age. And they are not even that old, less than 20yrs.

If I had ridden the Gixxer everyday, it likely would have racked up some impressive mileage by now. It's why I've decided not to keep a dedicated track bike, since I just don't use it often enough to justify letting one rot away like that. I'd rather have a bike I'm more likely to ride street but can double as a track bike. I bought the '18 Street Triple R exactly for this purpose. Folks tend to question Triumph reliability, no doubt because of poor reputation of all things English automotive. My experience with Hinckley triples have for the most parts being excellent, or at the very least no worse than other bikes I've had.
 
No fuel filter. It's not recommended to use a fuel filter with these, it tends to impede fuel flow and cause fuel starvation.

You can find a filter that will pass more than enough fuel for a 500 cc twin. I had one on my 1700 cc Yamaha Road Star with a gravity fed carburetor.
 
fitting that fuel filter in the available space would be a real trick.
I'd make that work.

(Remember, Berryman's Chem-Dip, set in the sun to warm up)

Cool to see you are an author and inventor.

I've only written one book, but I've invented a double handful of neat stuff (tech and toys). Never patented though...
 
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Old and no fuel filter used in the same sentence spells disaster , by the time it’s old the fuel system will be well crudded up and that crud is garunteed to migrate to the carb jets plugging them . Also look in the bottom of any fuel can you have in your garage , with a good light you will see crud in the bottom of it . Untill you fix the fueling problum your wasting time trying to keep it running . Same with the starter . Unless you can clean and rebuild it back to new specs it will give you trouble . Some things are built to last forever but most aren’t and these days we are in a throw away world . Very little is built with any plans for a long life .
 
Old and no fuel filter used in the same sentence spells disaster , by the time it’s old the fuel system will be well crudded up and that crud is garunteed to migrate to the carb jets plugging them . Also look in the bottom of any fuel can you have in your garage , with a good light you will see crud in the bottom of it . Untill you fix the fueling problum your wasting time trying to keep it running . Same with the starter . Unless you can clean and rebuild it back to new specs it will give you trouble . Some things are built to last forever but most aren’t and these days we are in a throw away world . Very little is built with any plans for a long life .
When possible, the very first thing I do with any bike I buy is installing an inline filter. New, used, whatever!
 
I will never own another carbureted motorcycle.

Oh, I dunno. You could have one like my '82 Ironhead Sportster. The single S&S "Shorty B" on it is so simple, even I don't screw it up.
Don't ask about the '78 KZ650. :doh: 4 little gas portals of pure torture.
 
In the automotive world, there are a few FI kits to update classics. Straight bolt-on with the required sensors and computer as a complete kit.
The motorcycle world needs this.
 
Well, today I finally went out and pulled the carbs. Yesterday I ordered a pair of carb rebuild kits with way more parts in them than I need, but fortunately all of the parts that I will be needing. Good thing, since I will be needing some carb parts!

First, as suspected, the pilot jets were completely blocked.
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I ran a little piece of wire through them to clear the blockage and put them in some Berryman's to soak for a while.

Also, the float needle seat o-rings are pretty much shot. I should say, completely shot.
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I am not even sure if I can reuse the seats. I think the rebuild kit comes with new ones. Also new float needles.

And one of the pilot needles was leaking fuel:
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I knew something in the carb was leaking fuel to the outside world, well that was it. I decided to change the o-rings on both carbs since I will have the parts to do it. This o-ring was flat and hard. The other one, which somehow wasn't leaking, was flat, hard, and cracked so it came out a "C-ring".

Not shown are the completely hard and cracked float bowl gaskets. Those will also be replaced.

Here's the thing. I completely rebuilt these carbs with all new o-rings and everything in mint condition about 4 years ago, and the bike hasn't had more than 1000 miles on it since then. I have only ever used ethanol-free fuel in it since then. So how did these o-rings degrade so massively in just four years?

Of course the problems were multi. Leaking float bowl seals caused it to leak fuel from the bowls into the cylinders when it sat, making it hard to start since it was simultaneously flooded and also the carb bowls were empty. So I'd have to put it on PRI every time I went to start it, and it would still be hard to start because it had to clear leaked fuel. Then the pilot jets were blocked so it just refused to idle. Amazing it ran at all at part throttle or low revs. Also explains why my efforts to adjust pilot mixture were not successful. Of course I knew this before I got it apart, but I confirmed it for sure.

So just like my gas string trimmer and my lawn mower, looks like my not-frequently-used gravel bike is going to require an annual carb rebuild.

FWIW I also ordered some enzyme fuel treatment to use not only in the GS500 but also my other gas tools in hopes that I can avoid the constant tinkering I have to do to make them work. And I did order an inline fuel filter, I will see if there's any way to fit it in there. Can't make it any worse, that's for sure.
 
mr72, I own a 2009 KLR that I ride enough to keep the ethanol free gas changed at least every two or three months. I run the carb dry after every use. The gas is also doctored with Performance 360. I bought it used with 4,000 miles around 2014. It's got 13,000 on it now. I've never had trouble with the carb. It just works... flawlessly. I'm 'just saying' this because your troubles are certainly way above my tolerance level. There is filter sock on the KLR petcock.

I saw your posts on the Adventure Rider thread about the safety of lane splitting. It's always interesting when the same user name is used on both TWT and Adven Rider. You made valid points.
 
I saw your posts on the Adventure Rider thread about the safety of lane splitting. It's always interesting when the same user name is used on both TWT and Adven Rider. You made valid points.
Hey, thanks for saying that. People just can't seem to separate logic from emotion in these issues. Just because I think the way the lane splitting advocates are going about it is doomed to political failure doesn't mean I hate the idea of lane splitting or as some more often suggest, that I personally am just "afraid" of it.
 
mr72, I own a 2009 KLR that I ride enough to keep the ethanol free gas changed at least every two or three months. I run the carb dry after every use. The gas is also doctored with Performance 360.

Yeah I think there's a huge difference between a 2009 and a 1992 bike. Everything on my bike is 3x as old as yours. Even rebuilding the carbs doesn't replace all of the old stuff. There's just so much you can't get to on carbs even to clean, much less recondition.

My dad has a 2006ish DR250 and it also fares much better with limited use and the carb. OTOH his 2005 or so Honda Shadow has begun to be a gigantic pain to keep working even though he rides it often. Among his three motorcycles, the only one that is somewhat trouble free is the only one with EFI. I think that's no coincidence.

Anyway, I'll get this fixed for sure, I just need to figure how to keep this bike working without having to ride it often. I can't run the carbs out of fuel each time I ride because you can't turn off the petcock. I could put drain hoses and manually drain the fuel from the bowls, but that'd be a colossal pain. The whole bike is a colossal pain.
 
So just like my gas string trimmer and my lawn mower, looks like my not-frequently-used gravel bike is going to require an annual carb rebuild.

FWIW I also ordered some enzyme fuel treatment to use not only in the GS500 but also my other gas tools in hopes that I can avoid the constant tinkering I have to do to make them work. And I did order an inline fuel filter, I will see if there's any way to fit it in there. Can't make it any worse, that's for sure.
Use non-ethanol gas from QT, it helps
 
If I ride my mid-60s British bikes once a week for at least an hour, and use non-ethanol gas, they'll stay running indefinitely without having to hassle with the carbs.

The reason you want to run ANY bike for at least an hour is, you must get the engine up to full operating temperature (typically about 1o minutes), then keep it there for AT LEAST 20-30 minutes, which causes any condensate in the system to boil off completely.

Otherwise, condensation mixed with oil will start to form corrosive emulsion wherever it sits inside your engine.
 
Another handy tip if you have ethanol in your gas (or not) is to reach in and drain each bowl with the installed screw. That will definitely stop issues, old o-rings and gaskets shouldn't be an annual issue after being replaced. Good luck with it. Hope to see it running soon. A cheap ultrasonic cleaner and some simple green or the like will definitely clean up cruddy pilots and mains.
 
The reason you want to run ANY bike for at least an hour is,

I suppose this may be part of the problem. Not just the oil, but overall, I don't tend to ride either of my bikes for an hour at a time except about once every few weeks.

I like to use my motorcycles as my primary transportation, getting the benefits of motorcycling while doing ordinary things. I haven't had to commute to work regularly in 5 years, so it's just errands, most of which I can do right here in Cedar Park. My routine usage pattern is a few trips a week, mostly five miles or less each way. If I happen to have one of my bikes sitting out on the curb when I have a break in my schedule I might sneak in an hour long ride about once every two or three weeks during the midday, but it's almost always the Triumph that's out on the curb begging to be ridden.

Due to my parking circumstances, I just wind up letting the Suzuki sit in the garage, only taking it out for rides where it is clearly better suited than the Triumph. That's no more than once every few months. So it might get a 50-100 mile ride every two or three months. I really don't see a future where I'll put more than 500 miles a year on this bike. I think it's this pattern that's contributing to the inability to keep it in a good state of tune.

There's a part of me that really wants to have this customized 30 year old motorcycle as a part of my fleet that I can take out and enjoy every once in a while, but it's proving to be terribly impractical. This is mostly why I haven't bought a third motorcycle; it would just reduce how often I could use the GS. Once I get this thing running just right, I might just have to sell it or trade it for something else. When I bought the Triumph I really considered a Ducati Scrambler instead, maybe now's the time for me to get the GS dialed back in and then let it go to someone else who can use it daily, and buy a Scrambler to use for gravel and rough road rides that will tolerate sitting for months at a time much better.
 
Viton orings are life time , buna n orings are not . No manufacture will use viton because they cost 1 cent more for the size orings that fit fuel inlet tubes on my KTMs . I buy them in bulk , they cost around 13 cents versus 12 cents for buna n . I used to keep Curtis supplied with them when he was dealing KTMs . Buna n orings need to be replaced every time they are disturbed when exposed to gas or diesel .
 
Viton orings are life time , buna n orings are not .

Every o-ring I replaced was done with Viton where available. Those pilot needle o-rings came from Suzuki so I am sure they were Buna-N. My recollection is that the last time I had the carbs apart, the float seat o-rings were ok so I didn't replace them, so they probably are also Buna-N.

My rebuild kit has all Viton o-rings in it according to the manufacturer. I'll probably go ahead and replace all of the dry o-rings in the top of the carb while I have it apart and just do it 100% right, whether they look like they need it or not. I sure hope you are right that the Viton o-rings will help me not have to do this over and over. I mean, it would not be so annoying except that it degrades without riding it. The cost to benefit ratio is completely upside down.
 
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OK, first, a picture.

I replaced the starter, which was a cinch with the carbs off. Then I finished putting the rebuild parts in the carbs. The rebuild kit didn't include the o-ring that goes on the float assy itself, fortunately I had some in my bin of o-rings. Replaced both float needles, both float needle seats, had already cleaned the pilot jets, replaced the o-rings on the pilot needles, reset float height and put her back together. Set the pilot mixture at 2.5 turns out as a starting point. Then I spent like an hour trying to get the fuel hoses back on the tank. This right here is why I hate this job. If I could do this without removing the tank or if I had some kind of quick connects for the fuel hoses then I wouldn't mind doing this as maintenance.

Once it was together I put the choke on and pushed the start button after putting it on PRI for a minute, fired right up instantly and ran good. So I shut it off, ran some errands, then later took it out for a proper test ride and dialing in of the idle speed.

Bike runs perfectly. Absolutely flawless. It had a stumble at 4.5K rpm and light throttle for a little bit when it was warming up but that eventually worked its way out. I filled up with fresh fuel while I was out riding it, ethanol-free from Walmart as usual. I wound up riding about half an hour or so, dialed in the idle speed at stop lights. Flawless.

This bike is back!!

Now I do need to sort out the long travel in the rear brake and soft pedal. But I wouldn't hesitate to ride this bike to anywhere right now. And I might just go ahead and fast track that trip to the Regency Bridge that I have been planning. Or ride it to Castell to my parents place along with the 20 miles of gravel county roads.
 
Just rode it over to have it inspected. Started easily but I think the choke is not exactly working as expected. Ran weird until it was warmed up, then ran perfectly again. I'm going to call this "done".
 
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