Picking up 1980 GS750 tomorrow. Have basic fluids questions.

[82tiburon]

Hello all, from sunny South Florida.
New to the forum, but not to the Suzuki TSCC engine --- I owned another GS750E from 1982 to 1991, but that was a long time ago & my memory's a bit fuzzy on certain details.

I recently came across a REALLY nice 1980 survivor --- exactly as the one I once owned, but in blue rather than grey --- and would like to get it home solid, safe & sound.

The ride home isn't too long (approx. 130 miles), but I believe in being prepared, so I'm getting together my 3-day assault pack with some roadside essentials "just in case".
I've already tossed in my metric hex key set, a ratchet wrench & sockets, and some box-end ones.

What I'd like to know is what type of brake fluid this bike used --- I believe it was DOT 3, but I'm not certain.
Knowing what weight of a quart of oil wouldn't hurt either...but again, my memory fails me.
It's getting up into the low-to-mid 80s already, so that's something to consider.

I [plan on doing a full filter & oil change once I get it back home but would like some suggestions for this emergency pack.

I currently own a customized 1974 Harley Sportster with gobs of hand-fabricated parts, but I just couldn't pass up on this GS for hops upstate & down to Key West for smooth riding without having to carry two saddlebags full of spares & such.

 

[Nessism]

DOT 3 or 4 brake fluid.

Rotella 15W-40 oil is the forum favorite.

Lots of useful links for your bike at this website including an owners and service manual...http://members.dslextreme.com/users/bikecliff/

 

[Steve]

Agree with Nessism, and will add that Suzuki recommended a 10w-40 oil or 20w-50 if temps were going to stay above a certain minimum. You will certainly meet that minimum in South Flori-duh. Just make SURE that you look on the back of the bottle at the API seal to be SURE that it does NOT say "Energy Conserving". Those oils have additives that don't play well with wet clutches.

Rotella is an oil forumuated for diesel engines. We like it in the bikes because it still has some of the Zinc and Phosphorous that have been removed out of general automotive oils. They are being removed because they tend to clog catalytic convertors on the cars that are being kept a long time and are wearing out, but those additives are what keeps the transmissions happy in our bikes.

.

 

[82tiburon]

Wow!
Thanks for such timely advice, guys, I can't begin to tell you just how much I appreciate it.

I can understand why you like the Rotella with zinc properties still in it.
I use Valvoline R in my old (1974) Harley for the exact same reason.

Will post pics of the bike as soon as I get her home.

 

[Steve]

Wow! Thanks for such timely advice, guys, ...

Only two replies in three hours. :-k

We have done much better than that. :-\\\

This is a rather active forum, so stick around when you post a question, there is a chance that it will be answered SOON.

By the way, why not take a few moments to update your profile? A location would be nice. No address needed, at town or at least a general area will suffice.
Who am I to ask for details? My own location is a decently-large area: "southwest oHIo".

Also take a few more moments to generate a signature. Does not have to be anything fancy, just a simple "Current bike: 1980 750" would do.
That way, you would not have to remember to mention it every time you ask a question. :encouragement:

.

 

[82tiburon]

I picked the '80 GS750E & the battery crapped out on me coming home --- had to have AAA flatbed me the last 15 miles or so. :apologetic:

I'm thinking the previous owner may have just given it a quick charge & let it go at that, because it definitely was NOT taking a charge as I rode it.
Tomorrow I'll be pulling the left-side cover panel, removing the battery (not even sure what kind it is) & doing my maintenance check/routine: metering it out, then hooking it up to the Schumacher, followed by letting it sit a bit before putting it on the trickle charger.
(I sure hope it's not a lead/acid unit --- I've had my share of paint jobs ruined when those suckers decide to start puking up}
A new AGM battery may be first on my shopping list.

I noticed a few oddities along the way:

1) I couldn't, for the life of me, find the fuel petcock/valve.
The owner claimed it was somewhere under the fuel tank but couldn't find it & had it set to "ON" continuously.
Very strange.

2} There's a Lights On/Off switch on the left grip, which is apparently locked up. I noticed a Torx screw in the side of it.
Anyone else have this?
While I'd prefer to start the engine with the lights off, I don't remember my old '80 having this feature.

3) The bike seems to sit overly high --- I'm 5'-10" and even wearing my engineer boots was tip-toeing at stoplights.
Maybe the shocks are set too high --- I'll have to check that out.

Otherwise, the bike rode like a dream (until it stopped), shifted & accelerated smoothly, and the tires are so new that the little "nipples" on the sidewalls are still there.
These little glitches & oddities are things that I can take care of --- I'm just curious if the think tank has ever come across them --- particularly the furst two.

As always, any & all tips, suggestions & advice will be GREATLY appreciated.

 

[gustovh]

If the battery checks out, run the checks on the stator and rr. Your fuel tap does not have a valve switch as such. On the left rear of the tank, just above the carb is the fuel "tap" there is a valve that shows pri or on, the slot in the valve lines up with the selected value. The gas tap is always on and flowing on pri once vacuum is applied and will continue to flow even with the engine off. With the valve pointing at on the valve shuts off with the engine.

V

 

[82tiburon]

Thanks so much for the prompt & very specific details --- it's going to go a long way towards getting her running again.

Today I pulled the airbox to get to the battery from on top --- I like to avoid those oh-so-fragile/oh-so-expensive side covers whenever possible --- & metered it out.
It was reading 11.43 volts & needed some distilled water in a few of the cells.
I've got it doing the slow charge routine on the Schumacher...but I just HATE lead/acid batteries & will be replacing it with an AGM unit as soon as I can find one that fits.

Any suggestions on how many amp hours & cold-cranking amps (CCA) to go for?

Your continued help is, as always, greatly appreciated.

 

[Guest]

15w40 diesel oil sucks
don't use the manufacturer's recommended viscosity, there is a guy on the internet he knows better......
and you'll save so much money too

 

[Guest]

Thanks so much for the prompt & very specific details --- it's going to go a long way towards getting her running again.

Today I pulled the airbox to get to the battery from on top --- I like to avoid those oh-so-fragile/oh-so-expensive side covers whenever possible --- & metered it out.
It was reading 11.43 volts & needed some distilled water in a few of the cells.
I've got it doing the slow charge routine on the Schumacher...but I just HATE lead/acid batteries & will be replacing it with an AGM unit as soon as I can find one that fits.

Any suggestions on how many amp hours & cold-cranking amps (CCA) to go for?

Your continued help is, as always, greatly appreciated.

I use Interstate batteries exclusively for all of my vehicles. They have a book which will list the required battery for your machine. They're a little more money but trustworthy.

 

[Nessism]

Better check the charging system while you are at it. GS bikes have issues with charging. Details on how to check can be found on basscliff's site or in the service manual.

 

[82tiburon]

15w40 diesel oil sucks
don't use the manufacturer's recommended viscosity, there is a guy on the internet he knows better......
and you'll save so much money too

I'm actually thinking of going with Valvoline VR1.
Have had great results with it, though in a much heavier grade (60 weight) in my Harley going on about 7 years now.

 

[alke46]

15w40 diesel oil sucks
don't use the manufacturer's recommended viscosity, there is a guy on the internet he knows better......
and you'll save so much money too

Huh?? I thought the consensus on this site was in favor of the Rotella 15w40 diesel oil. There are a lot of us using it with no regrets.

 

[Nessism]

Huh?? I thought the consensus on this site was in favor of the Rotella 15w40 diesel oil.

It is. derwood is smoking crack.

 

[82tiburon]

So, the lead/acid battery took FOREVER (as in, overnight) to fully charge on my Schumacher & took nearly 4 oz. of distilled water as well.
Not a good sign.

Yesterday morning it was finally fully charged & settled down to a stead 13.34 volts on my tender, where I kept it for about four hours.
Having already pulled the airbox to check the air filter & rear brake resevoir level, I dropped the battery back in and...VOILA!
It cranked over like a charm & when I put my voltmeter prongs to the battery I got increasing voltage as I slowly rolled on the throttle...YAY!...no charging issues.

As an added bonus, I was able to take apart the mysterious Lights On/Off switch which wouldn't budge, see that someone had picked the wrong set-up (it left the light permanently "on").
It mounted onto a prong, which functioned perfectly at shutting off the lights before starting the engine.
I figure to probably put a small, antique cork stopper over the prong, giving it my own personal touch & hopefully, a bit more class.

Next up is s**t-canning the existing battery, before it goes south on me, with a Deka ETX15L.

 

[Nessism]

Headlamp on during starting is no issue on a properly functioning bike. The bike will light off with just a quick jab of the starter. The bikes charging system is designed to support the headlamp on all the time as well. Turning it off will result in the system producing too much extra power which in part will then be shunted back to the stator where it can cause heat damage. That's why standard forum wisdom includes, to go along with Rotella oil, a Shindengen SH775 series type R/R. It helps protect your stator from overcharge damage. You can get these units for less than $40 shipped off ebay. One of the best investments you can make on your bike. Save that fancy oil for a bike that needs it and get a proper R/R.

 

[Guest]

I'm actually thinking of going with Valvoline VR1.
Have had great results with it, though in a much heavier grade (60 weight) in my Harley going on about 7 years now.

Lol, way too heavy for the 750, I run a 20w-50 synthetic in mine during the summer here. Yeah heat and lots of it. Doesn't do too bad in the winter either, what little winter we get here. Guess it is the reason mine has 67,000 miles on it now and never been into the engine.

 

[82tiburon]

Lol, way too heavy for the 750, I run a 20w-50 synthetic in mine during the summer here. Yeah heat and lots of it. Doesn't do too bad in the winter either, what little winter we get here. Guess it is the reason mine has 67,000 miles on it now and never been into the engine.

Ah, at least you get the dry heat. :subdued: :subdued: :subdued:
With 80%-plus humidity down here, getting caught in a traffic jam can cook your motor in no time at all --- which is why I split lanes.

My only concern with the 20W-50 are the oil passages.
Some engines have them very narrow & require a lot of pressure to push that dino juice through them --- which is not a good thing.
Learned that from over 30 years working on bikes & boats.
I may look into Valvoline's conventional 4-stroke motorcycle oil in 10W-40.I just can't abide the idea of running tractor oil in anything other than...well, a tractor.

 

[82tiburon]

Headlamp on during starting is no issue on a properly functioning bike. The bike will light off with just a quick jab of the starter. The bikes charging system is designed to support the headlamp on all the time as well. Turning it off will result in the system producing too much extra power which in part will then be shunted back to the stator where it can cause heat damage. That's why standard forum wisdom includes, to go along with Rotella oil, a Shindengen SH775 series type R/R. It helps protect your stator from overcharge damage. You can get these units for less than $40 shipped off ebay. One of the best investments you can make on your bike. Save that fancy oil for a bike that needs it and get a proper R/R.

Nope, can't find a single Shindengen SH775 on eBay.
Is there a direct manufacture's website for them?

 

[82tiburon]

Well, even with the stress of escorting my wife to the hospital for her chemo therapy, I've been able to get some important things done on the bike this week.

I was able to resuscitate the lead/acid battery enough so as to ascertain that my charging system is functioning properly --- it metered out from a sitting 12.33 volts up to 12.70 just below 3500 RPM with a slow roll of the throttle.

I made a cork cap button for the Lights On/Off switch to give it my own individual touch.
While I have NO INTENTION WHATSOEVER of running the bike with the lights off, that is the way I will be starting it.
The nanosecond it will take to do this isn't sufficient to harm the stator or regulator/rectifier.

I purchased a replacement Deka ETX15L gel battery, washable/reusable K&N SU-1250 canister air filter & a K&N #133 oil filter.
K&N is all that I've ever used in all of my vehicles, including a 1982 COrvette that I used in autocross racing.
They make quality products.

I'm going to go with Valvoline conventional 10W-40 motorcycle oil.It goes for $4.00 & change
at Walmart and looks to be good stuff.