Old Bike, new rider, same ol' problems - 1980 GS550E

[NateDogg83]

Hello!

This weekend I finally picked up my first bike, something local I had been eyeing since it looked to be in really decent condition, a 1980 GS550E with a little over 19K miles(30.5 KM).



A nice middle aged guy had owned it for the past 13 years, putting in WAY more love than one would think to it, wintered it up 4 years ago and hadn't ridden it since due to his kiddos getting older, sold it to me for a very reasonable price (at around a little more than a grand) for a bike that was very clean, and still cranked but didn't run.

After renting a U-haul sprinter van getting help from a friend, we got it loaded up in a way less sketchier way than any of us thought, and brought her home to get working on her.

After giving it a once over with my dad (who used to own sport bikes when he was my age) it looks like I got a really nice ride.

Pads, rotors, battery and tires were all fresh (for being 4 years old) since he replaced it all the last year he rode it. I do have a aftermarket front brake handle/rez, but included in the litany of extra parts that came with the bike is the original handle/tank that's seized up.

He told me over the years he had the bike he had tank properly coated since he was never able to find a decent condition one anywhere, and he repainted the bike from the factory black to Ford Highland green, and put on gold Suzuki badges to pair better with the green. He also took off the stock rear view mirrors as the aftermarket clutch handle wasn't left hand thread so it aways came loose from the wind, and put on smaller square mirrors on instead.

Other than that the bike is pretty much stock. original wheels, seat and turn signals, as well as the original gages.

I was able to get off the carbs with not much struggle, and over the weekend i slowly worked to get it all apart and cleaned up.

I had to get the bike out of the garage by Sunday night and back to my apartment, so I went with a Amazon carb rebuild kit as I needed new gaskets as well as new main jet filters and seats. the bike came with a a whole spare set of carbs (unracked) + misc. bits but didn't have all the parts i needed so I took what i could get with 2 day shipping.

After waiting all day for the amazon truck, i was able to get the new float bowls, main jet seats and gaskets in and the carb back on the bike (TIL its easier to get the carbs in when you take the airbox bolts off to let it move around, who would have thought?) and to me and my dads surprise, she started right up with a couple cranks!

Unfortunately, even after a disassembly and thorough cleaning, I am not getting fuel to cylinder 1, and inconsistent fuel to cyl 2. 3 and 4 are running fine, enough that the bike will idle and can be driven around which still made me happy.

It was unfortunately late at that point, so my dad rode the bike over to my apartment (i only have my TIPIC, and am not allowed to ride at night yet) but all in all both me and my dad already have really great thoughts about the bike. My dad described it as so comfy it was like riding a couch compared to his GSXR 1000 he rode around on back in the day, and thinks it will be a great bike for me to ride around town and to work on. '

Ill post up some pics of her when i get home, new to the forum to will have to figure out if i have to host the pics somewhere else.

 

[Rich82GS750TZ]

Welcome. Great story. Yes, hosting pics somewhere else is a good idea. Someplace that can give you the BBCode to copy and paste here in a post.

I've written quite a bit about it. Click on the orange text and go to post # 6. Posting Pics

You can also post pics directly to the forum from you phone or computer using the image icon in the reply tool bar. That usually ends up a frustrating experience for me. Size restrictions, etc. And I'm just used to doing it the other way.

 

[gtem]

Congrats on the 550! What is a "main jet seat?" As soon as I heard "amazon Carb kit" I'm quite suspicious. Did you use the jets in the kit? Sounds like you'll be taking the carbs back off. So it's idling on 3 cylinders and being ridden as such? I'd do some bench testing of the carbs with filling the bowls via the fuel inlet that feeds the whole rack, then draining the bowls to confirm whether they all have the same amount of fuel in them.

 

[NateDogg83]

Congrats on the 550! What is a "main jet seat?" As soon as I heard "amazon Carb kit" I'm quite suspicious. Did you use the jets in the kit? Sounds like you'll be taking the carbs back off. So it's idling on 3 cylinders and being ridden as such? I'd do some bench testing of the carbs with filling the bowls via the fuel inlet that feeds the whole rack, then draining the bowls to confirm whether they all have the same amount of fuel in them.

I'm still pretty new to carbs, main jet seat is the wrong thing, I meant the float needle seats.

I did not use the jets in the carb kit (their 92.5s), I reused what was already in the carbs, 102 on the outer cylinders, and 110s? on the inners. Definitely pulling them again this weekend. I do know all 4 are getting fuel, as they all dripped fuel out the drain screws.

I did need to use the amazon float needles and seats as I damaged a couple of the stock ones trying to pull them out, the o ring turned to rocks on a couple of them and I had to use vice grips to get one really stuck one out. I unfortunately shot one of the stock float needle retaining clips across my garage while taking it off and its now gone. I have spare stock seats that have the correct detent ring for the stock retaining clips, but don't have any spare clips. of course the amazon ones don't have them, and the float needles in the kit have the pin clip built into them to hold directly onto the float height adjustment tab, so i had to use the amazon seats and needles.

In the spare carb bits box i have a set of nice C&L needles, but unless I can source another stock clip i cant use them.

Funny enough all 3 seems to have no problems, but I kept the original needles and seats in one of the outer ones as it looked like it had already been replaced, might be source on why cylinder 1 is getting no fuel.

I also suspect that cyl 1 slide diaphragm is sticking and not lifting to allow the carb to jet out fuel into the emulsion tube, but that's just a hunch. i remember one of the outsides ones was stickier than the other 3.

Can i take the intake box off to see if the slides are moving while the bike is running? or will the carbs run so poorly it wont idle with the airbox off? I do have 2 nice K&N dual pod filters but I don't plae to use them, not a big fan of the way they look.

I only drove it back to my apartment from my dads garage as I had to have it out by the weekend so my dad can park his car. with the inconsistent throttle my dad doesn't want me to learn how to ride on it yet, so its just sitting covered and locked in my parking lot.

 

[salty_monk]

Welcome to the forum. You're in the right place...!

 

[gtem]

Another thing to take a look at is a bench sync: making sure the throttle plates are exposing the pilot/idle holes evenly (also make sure they all flow well when you shoot some WD40 or something through them with some compressed air). That's to start, and then ideally a "real" sync with a quad vac setup. The 850G I'm working on currently had a dead cylinder when I first fired it up after a carb cleaning, I meant to do a "bench sync" but second guessed myself at what I saw as an inconsistent setting of the cyl #2 the throttle plate. Once I tweaked it on the bike I had all four cylinders kicking in at idle, at which point I hooked up my carb-tune and did the fine adjustment.

 

[NateDogg83]

Another thing to take a look at is a bench sync: making sure the throttle plates are exposing the pilot/idle holes evenly (also make sure they all flow well when you shoot some WD40 or something through them with some compressed air). That's to start, and then ideally a "real" sync with a quad vac setup. The 850G I'm working on currently had a dead cylinder when I first fired it up after a carb cleaning, I meant to do a "bench sync" but second guessed myself at what I saw as an inconsistent setting of the cyl #2 the throttle plate. Once I tweaked it on the bike I had all four cylinders kicking in at idle, at which point I hooked up my carb-tune and did the fine adjustment.

thanks for the advice, from my initial assessment I think the throttle plates are properly synced, but Ill take the carbs off this weekend and properly check using a light to see if theirs some slight difference. not sure if i can use feeler gages to check their clearance, but ill try. Sadly don't have any pin gages, when i worked at a machine shop they were so handle for finding clearances.

Ill probably build a DIY home fluid vac with some clear tubing and a board to sync the carbs. I haven't heard great things about the amazon kits, and their not cheap enough for me to buy just to use once. The local motorcycle shop is backed up for a couple weeks on carb work, and they gave me a (IMO) F off quote of $580 for 4 hours of labor PLUS whatever parts they would order. I just cant justify spending half of what the bike cost me on carb work that I can and should learn to do myself.

Im not stranger to doing mechanic work, ive modified my DD Audi A4 significantly, and i like wrenching on old sh*t(My A4 is a 05) as much as is it very frustrating at times.

Do you happen to know what thread size the vacuum bolts are? Id like to grab the right size nipples to reduce the chance of any leaks while trying to adjust them.

 

[gtem]

thanks for the advice, from my initial assessment I think the throttle plates are properly synced, but Ill take the carbs off this weekend and properly check using a light to see if theirs some slight difference. not sure if i can use feeler gages to check their clearance, but ill try. Sadly don't have any pin gages, when i worked at a machine shop they were so handle for finding clearances.

Ill probably build a DIY home fluid vac with some clear tubing and a board to sync the carbs. I haven't heard great things about the amazon kits, and their not cheap enough for me to buy just to use once. The local motorcycle shop is backed up for a couple weeks on carb work, and they gave me a (IMO) F off quote of $580 for 4 hours of labor PLUS whatever parts they would order. I just cant justify spending half of what the bike cost me on carb work that I can and should learn to do myself.

Im not stranger to doing mechanic work, ive modified my DD Audi A4 significantly, and i like wrenching on old sh*t(My A4 is a 05) as much as is it very frustrating at times.

Do you happen to know what thread size the vacuum bolts are? Id like to grab the right size nipples to reduce the chance of any leaks while trying to adjust them.

This is what I use, sadly they have gone up in price not insignificantly since I bought mine about 4 years ago:
https://www.ebay.com/itm/2254946819...zfxgkgO3y0QDww0QGSGmwun7iChsPgIcaAg9UEALw_wcB

As to the vac port thread size, I'm not confident in saying offhand, my current 850G came to me with some flavor of chinesium intake boots with M5x.08 bolts plugging the ports so I'm not confident how similar to OE they are or not.

 

[dgates1]

I suggest you get a Morgan Carbtune Pro for balancing the carbs. Not too expensive and very easy to use. Comes with the correct nipples you will need for the hoses. Chances are you will be taking the carbs off again in the future as a matter of maintenance and it's a good idea to balance them again when you do.

 

[NateDogg83]

couple weekends later update:

2 weekends ago I ended up pulling the carbs again and cleaning out the idle jets, they were all gunked up and I should have just pulled them out the first time (against the advise of my dad), and that sorted out all my lack of fuel to cyl 1 and 2.

later than week, i found some riding gloves for a decent price on FB that were local, and the guy selling them just so happened to work on old UJM bikes on the side, flipping them and just riding them around, and offered to help with getting the engine tuned up.

so this last weekend I stopped by since he had a carb sync and he was able to get them DIALED in. I didn't have much time to get riding myself (my first attempts in my neighborhood parking lot ended up with the bike on the ground, a cracked brake handle and chipped back cluster housing.) while i think i can buy a used new one, I think ill take a crack at modeling the housing up in CAD and test printing a new one. I have my MSF course scheduled for next month, definitely want to take it to help with the slow speed stuff.

safe to say ill need a much larger parking lot to get a handle of the tiny clutch grab and the (now much better) touchy throttle. this probably wont be the last time drop it either.

My dads impressions after the sync and riding it back home is that the clutch might be slipping on the high RPM shifts, so I might crack open the clutch case this weekend to get eyes on the steel and friction surfaces. hopefully none have any hot spots or friction pads missing.

my case guards did come in from Ebay but im having a bitch of a time getting bolts for it, since the stock ones arent long enough with the non removable washers. I thought the bottom engine bolts were M8s but their actually M10s to match the top long cross bolt. Not sure if they're coarse or fine thread for the teardrop bolt, will have to take it with me to the autoparts store and hope they have the 60mm ones I need.

 

[Nessism]

A slipping clutch can often be fixed by installing new OEM springs. And lube the cable and actuation helix while you are doing maintenance.

 

[Rich82GS750TZ]

Re: Replacement bolts. A good hardware store that sells individual bolts/nuts/washers in metric and has handy thread gauges is usually a better bet for replacement hardware than an auto-parts store. I'm fortunate to have a few in my area. Be sure the bolt you get isn't too long that it touches the engine case on the back side of the teardrop shaped nut.

 

[rphillips]

Just me, Clutch "might" be slipping? That sounds a lot like it "might not" be slipping. I Wouldn't even buy a clutch cover gasket till I knew for sure.

 

[Rich82GS750TZ]

"Clutch Slipping": Is that coming from your Dad, the same Dad that initially told you not to bother removing all the jets and thoroughly cleaning them? Maybe i read you're post wrong: "they were all gunked up and I should have just pulled them out the first time (against the advise of my dad)"

I'm not disparaging your Dad. I'm a Dad who tries to impart my knowledge onto my sons, and my Dad taught me a lot about a lot, including motorcycles.

But, "dad (who used to own sport bikes when he was my age)" might have done a lot of "high RPM shifts" on his sport bikes. And I'm not saying he's wrong. Your clutch very well may be slipping. But letting off the throttle, clutching and upshifting is the way you should be doing it (in other words - low RPM). Unless he's talking about rev-matching for the down-shift. You're just starting out on motorcycles, for get about that for now. I didn't read where you did an oil change (maybe I missed it). But that is where I would start. Cheap motor 4-stroke motorcycle oil from Walmart is just fine, or Rotella T4 15W-40 is fine too. Anything with a JASO MA spec. I don't want to turn this into an oil thread. But treating your clutch to fresh proper oil could clear up the "slipping" with a few miles. IMHO

Best of luck with your MSF. That really is the best place to start. Their course bikes are likely 250CC and typically very comfortable even for short riders.

 

[Rob S.]

A slipping clutch can often be fixed by installing new OEM springs. And lube the cable and actuation helix while you are doing maintenance.

If I were 'freshening up' my clutch, I'd also go with a brand new OEM clutch cable. I'd save the old one for an emergency.

 

[NateDogg83]

"Clutch Slipping": Is that coming from your Dad, the same Dad that initially told you not to bother removing all the jets and thoroughly cleaning them? Maybe i read you're post wrong: "they were all gunked up and I should have just pulled them out the first time (against the advise of my dad)"

I'm not disparaging your Dad. I'm a Dad who tries to impart my knowledge onto my sons, and my Dad taught me a lot about a lot, including motorcycles.

But, "dad (who used to own sport bikes when he was my age)" might have done a lot of "high RPM shifts" on his sport bikes. And I'm not saying he's wrong. Your clutch very well may be slipping. But letting off the throttle, clutching and upshifting is the way you should be doing it (in other words - low RPM). Unless he's talking about rev-matching for the down-shift. You're just starting out on motorcycles, for get about that for now. I didn't read where you did an oil change (maybe I missed it). But that is where I would start. Cheap motor 4-stroke motorcycle oil from Walmart is just fine, or Rotella T4 15W-40 is fine too. Anything with a JASO MA spec. I don't want to turn this into an oil thread. But treating your clutch to fresh proper oil could clear up the "slipping" with a few miles. IMHO

Best of luck with your MSF. That really is the best place to start. Their course bikes are likely 250CC and typically very comfortable even for short riders.

My dad said it was slightly slipping on high rpms shifts, but wasn't on lower or normal shifts. He has plenty of riding experience since he's ridden all sorts of bikes since he was kid, but none of them were carb'ed, so hes just as new to it as I am. He really pushed it on the ride home after getting it tuned up and other than the slightly slipping its otherwise fantastic, compared the seat to a nice cushy couch compared to his old sport bikes.

we talked some more this afternoon, and it might be that i picked up synthetic heavy duty diesel 15w-40 instead of the normal Rotella stuff. Ill look to see if Oreillys has the JASO MA oil, since their the only local parts store that sells motorcycle stuff or just grab the non synth oil and change it over.

I also will pull the clutch cable and give it a fresh lube, the throttle and choke cables were a little stiff and needed some, so it probably does too.

 

[salty_monk]

It’s quite common that clutches need new springs on these old bikes (if you buy aftermarket use 50% of them (3 old and 3 new alternate in the circle) as otherwise you’ll need a hand like King Kong!).
It’s a cheap thing to try as it’s only $10 plus a gasket.

my guess is that will sort out what Dad is feeling.

 

[gtem]

"and it might be that i picked up synthetic heavy duty diesel 15w-40 instead of the normal Rotella stuff."

The diesel 15W-40 is *exactly* what you want, and it's what carries the JASMO MA spec.

Once the oil is changed, I'd check to make sure the clutch is properly adjusted before condeming the plates or springs.

Getting those case guards installed is a great idea by the sound of it. I'd be 100% focused on getting throttle and clutch control sorted out. Just practice smoothly starting. As you're probably learning, it really doesn't take much throttle input, moreso smooth clutch work and feeling that friction point.

Good luck!