just bought a 78 GS 1000

[Fat Don]

Hi, I'm a noob so bear with me. I have been looking for a seventies muscle bike for about six months now. I originally wanted a nice, early 70's CB 750. After discovering the high demand for these i decided to expand my search and look at other bikes as well. The more information I read and pictures I looked at I realized I really wanted a bad ass muscle bike for less than $2000 that I could start riding right away without the worries of constant mechanical attention. Well, I found this 78 Suzuki GS 1000 on craigslist and the owner assured me it was a good runner with only 9000 miles on the clock. Sounded good to me so I went to see it and took it for a spin. Damn, that was a fine ride so I figured I'd make my offer. He was asking $2495 and I brought $2000 cash and asked if he would take $1800 and he said show me the money. So, I was riding the bike home (70 miles) on the freeway at 60-70 mph and all of a sudden it sounded like I was running out of fuel only I had just filled up. I was in 5th gear and holding steady at 65mph but giving it more throttle had no result and in fact after another mile things got worse, I started losing power and the bike was coughing and stammering. Crap, so I pulled off at the next exit and decided to limp home on the backroads. It felt like I had fouled a plug. I was able to nurse the bike for another 3-4 miles and came to a stop sign when the bike just flat out died and would not restart. So, after talking to the guy I had just bought it from and discovering he was on the road in the opposite direction, I decided to try starting it again. I thumbed the starter a few times and it wanted to start but would'nt. Not being a mechanic I just scratched my head and tried the choke. Eureka, bike started and I took off. I kept my speed to around 50 mph and the bikes power was back! I got home and checked the plugs, they were fine. I've ridden the bike maybe 70 additional miles, all under 70mph with the exception of a few short blips on the throttle, and the bike has ran awesome. What gives? The guy who sold it to me suspects a hole in the petcocks diaphram. Diaphram? Can I fix that myself? He also said the plugs should be changed to the OEM plug cause the ones in it don't really belong to it. What? Can someone recomend the correct plug to use? I started looking at the bike and the number stamped on the engine does not match the number on the frame. What's up with that? Could my bikes odometer mileage be different than what's on the motor? I really like my bike and have started to envision a mild restoration on it. I'm not a mechanic but I do have a lot of experience working on "things" and I have lot's of tools and I'm fairly quick to pick up on things but have never done any "real" work on bikes. Anyway, I hope someone reads this and can answer my questions and look at my pictures. Did I get a good bike at a good price? Whats up with those numbers and the diaphram and the plugs?

 

[Fat Don]

 

[BassCliff]

Greetings and Salutations!

Greetings and Salutations!

Hi Mr. Fat Don,

It's normal for the fame #s to be different from the engine #s. Thanks for the pictures, looks like you've got a fine machine.

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community.

If you suspect a bad petcock, save yourself a lot of grief and just get a new one. These old bikes really like having all of their electrical connections cleaned too. Installing a dedicated ground wire from the regulator/rectifier directly to the negative terminal of the battery is a compulsory modification. I like to add Sea Foam to a tank of gas a few times a year, just for maintenance. Thanks for joining us, keep us informed.


Thank you for your indulgence,

BassCliff

 

[Fat Don]

great advice! new petcock, clean the connectors, hardwire the rectifier,new plugs and some sea foam. now i have a starting point anyways.

 

[Big T]

Don,

Your running out of gas could be gunk from the gas tank clogging the carbs ,or a clogged vent in the gas cap.

Did the gas cap make a sucking sound when you took it off after the motor stopped running?

Nice looking bike, it's been modified a bit - different gas tank,headlight ears.

 

[Fat Don]

I'll keep an ear out for that sucking sound if the problem re-occurs. When it happened the one time, I did not remove the gas cap. I only turned on the choke and the bike started so I rode away and turned off the choke once I was riding. The bike has ran superbly since, there is some minor backfiring and the bike seems to make a sound like it's not quite warmed up even though it is.

 

[rudy]

Sounds a tad lean. If your petcock is partially clogged (would explain why it died on the way home) the level in the float bowls would be lower, thus making the mixture leaner. Lean = backfires, especially on decel. I'd say get a new petcock anyway. They're cheap and easy to do. Good peace of mind to know that you're not gonna fill your cylinders and crankcase full of gas from a leaky petcock either. Should check for an inline fuel filter as well. If it's clogged, it'll slow down the fuel as well.

Check your plugs again. Take special note of what colours everything is. Black is rich, white is lean, you're looking for a nice tan colour with no buildup of carbon. Look up plug charts, it'll help you out. Oh, and you should be running the stock plugs as well. Just to make sure everything is right, and since you already know they're not stock ones.

Other than that, spark plugs will be NGK 14mm B8ES Spark Plugs. These will be available to you locally, or you can go through Z1 Enterprises too. http://www.z1enterprises.com/detail.aspx?ID=211


That's a real nice lookin bike you have. Coming from a fellow 1K owner, they're great bikes to work on as well. I didn't have the pleasure of riding mine last year after I picked it up, but am doing a full rebuild/restyle in Cooley replica styling. This coming summer will be a good one. There's lots of 1000 owners on here. Lots of them very knowledgable about their bikes. Just stick around and read lots, you'll pick it up quickly.

 

[Fat Don]

Thanks! I appreciate everyones advice and comments.

 

[Sandy]

Nice ride, although not totally stock it looks good and seems in pretty good shape. One quick thing to check is the vacuum line to the petcock. Make sure is not gone hard, rotted, cracked or loose fitting causing the petcock to only partially open. Any questions, just ask away, there's lots of folks here willing to help.

 

[rphillips]

If it starts messing up again, turn the petcock to Pri. If it clears up, it's probably a leaking vacuum line to the petcock or the petcock itself.

 

[russr33]

Don that sounds like exactly the same problem I had on the GS1100 I just sold. It would only do what you discribe (loss of throttle response and finally die) at freeway speeds. It was the gas cap. These old GS's have vented gas caps, as was stated earlier. Just take your cap off, flip it over and take out the screws and clean it good with carb cleaner. Then when you have re-assembled it, spray some in the key hole and work the key in and out for awhile. Should cure your problem.

If you want to make sure that is your problem, siphon some gas off (or wait until your about half empty) and run it on the freeway for awhile with the gas cap off. If you still have the problem then you can look at petcock or vacuum line. If it doesn't you know it's the cap.

BTW- The NGK B8ES sparkplugs will be available at your local auto parts store.

 

[anthonygs1000]

nice bike

nice bike

sweet looking bike !!!!!!!!!! is that a 1979 tank ?

 

[rudy]

I hope you realize that you just bought a 30 year old bike. GS's are reliable but not if they are neglected.

On the GS's that I've bought I always go through the carbs, check the valves, clean out the brake system, etc, before attempting to put the bike on the road. Better to do all the maintaince instead of leaving things up to chance.

^^^^^^Wise words to live by^^^^^^^^

I bought my 1k as a "runner". Yeah, right! Just as much work to do to it as bikes I've bought that sat for 5 - 10 years or more. Brakes were the least safe things I've seen yet. Leaky MC's, sticking calipers, the whole 9 yards. Fluid that was near black. Carbs gummed up beyond belief (it was a miracle it even ran). Wiring that was SKETCHY at best. Oil leaks everywhere. Needed a new muffler and suspension. And this guy honestly thought it was worth $1800. I told him he was nuts. I paid $1400 with all his extras. About $800 too much for the work that needed to be done to make it ACTUALLY roadworthy.

So I guess the words to live by are, don't assume something is good just because it seems to work. Take it apart and inspect it, clean it, and rebuild it. Especially safety items. You'll end up with a bike that will last you 30 more years with a little regular preventative maintenance.

 

[Suzuki mad]

HI.

Thats a later tank on your bike and the seats missing its plastic base.

All old bikes have problems either from PO or age. The beauty of them is that they are nearly bomb proof and you don't have to have complicated equipment to keep them running.

Its likely to be a blocked tank vent, fuel tap or the vacuum line which has been said before. Be an idea to get a manual for the GS.

Suzuki mad

 

[Fat Don]

You guy's have given me some great tips. I'll check it all out immediately. The guy who sold me the bike did say the tank was off another bike, he was'nt sure what year. I don't mind, I think it looks great on there. I don't know what the deal is with the missing plastic base on the seat but it does not seem like it's needed at this point. I would like to replace the drag bars that are on it and the turn signals and headlight with either original parts or close to original looking. Also that exhaust has to go. The area where all four exhaust pipes converge to one is dragging on right hand turns even at moderate to low speeds. I'm hoping to find a set up with two into one exhaust.

In the above picture you can see a square patch of metal welded to the underside of the pipes. That area is hitting the pavement on almost all right hand turns.

You can see that straight "drag style" handle bar here and those tiny turn signals and the headlight which may or may not be original but I dont really like it too much. I prefer a more classic, original style set up.

 

[Big T]

That looks like a drag racing style header on there, so no wonder it drags

The turn signals are not original, and are much smaller

The headlight shell may be original, but the "ears" that hold it on the forks are not.

You can check the Gallery for a 78-79 and see what it should look like.

It looks like it needs new fork seals, the ring around the tube is a dead giveaway.

 

[Zooks]

and run it on the freeway for awhile with the gas cap off.

No offence to russr33 but I would definitely never do this. In the rare event that you were to come off there would be fuel spilled all over the ground, the bike and possibly you. Dying a fuel soaked, firey death is not a pleasant thought.

 

[Zooks]

BTW Don, welcome aboard the best motorbike forum on the internet. You're guaranteed to get the right advice here.

 

[Fat Don]

Thanks for the welcome! Yesterday I purchased a PDF service manual for my year bike and I'm pretty sorry I did. The pictures are cruddy because the person selling the PDF just scanned the pages from his manual and they are quite unintelligible. I can read the page just fine but those pics are horrid. Today I went and bought the correct spark plug for the bike and some carb cleaner and sea foam. I was hoping to pick up an inline fuel filter as well but they did'nt carry anything like what I have on my bike. I got home and went to put the plugs in and the freakin head on the top of the plug is different than the plugs that are on the bike and so the plug wire wont fit over the top of it. Damn, it's always like this for me, even the simplest of things becomes complicated as soon as I try doing it myself. The right plug is what came with the bike and the left is what I bought. Do they carry the same plug as I bought only with a different head on it?

It looks like it needs new fork seals, the ring around the tube is a dead giveaway.

What rings exactly? The one the arrow is pointing to?

 

[Sandy]

Actually the top piece of the plug should just thread off with a pair of pliers. As for the fork seals the rings could be a sign that they are on the way out and leaking oil past the seal. However that is not uncommon on a bike that has sat for a while and may go away after you've ridden it a bit. The seals get hard from sitting but once they're exposed to some fork oil the they soften up a bit. It is a sign though that replacing them should be put somewhere on the to-do list, like right beside a set of Progressive fork springs to replace the bagged out stock ones if the they haven't been changed already.