1978 GS 1000 - Video Tech Support Request

**BassCliff** · 04-13-2011, 06:34 PM

Greetings and Salutations!!

Hi Mr. SandPVRR,

That's a pretty good looking skunk you have there.

There is a standard list of maintenance duties for these 30 year old bikes. Rubber is old, parts are gummed up, electrical connections are corroded, etc. Everything starts with properly cleaned carbs and a valve adjustment. I don't mean taking off the float bowls and spritzing the main jet with some carb cleaner. They must be completely disassembled and dipped in carb cleaner for up to 24 hours. You'll find most of the detail you need in the links below. You'll want to reference the VM carb rebuild guide to start.

What do the plugs look like? Is there good spark on all? If the petcock is leaking it can foul the #3 plug. Have you checked the compression? If it's been sitting a while a ring could be stuck. But it should un-stick once you start riding it.

Anyway, let me dump a TON if information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Rebuild Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. Now let me roll out the welcome mat for you...

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. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

**Nessism** · 04-13-2011, 06:59 PM

Originally posted by BassCliff

Hi Mr. SandPVRR,

That's a pretty good looking skunk you have there.

There is a standard list of maintenance duties for these 30 year old bikes. Rubber is old, parts are gummed up, electrical connections are corroded, etc. Everything starts with properly cleaned carbs and a valve adjustment. I don't mean taking off the float bowls and spritzing the main jet with some carb cleaner. They must be completely disassembled and dipped in carb cleaner for up to 24 hours. You'll find most of the detail you need in the links below. You'll want to reference the VM carb rebuild guide to start.

What do the plugs look like? Is there good spark on all? If the petcock is leaking it can foul the #3 plug. Have you checked the compression? If it's been sitting a while a ring could be stuck. But it should un-stick once you start riding it.

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

Yes this!

Maintenance is good!

Rebuild the carbs, sync the carbs, adjust the valves, check the charging system, new tires, chain (as necessary), etc...

Trying to diagnose a bike without knowing the status of all the maintenance is folly.

**SandPVRR** · 04-13-2011, 07:07 PM

All,
A bit more history:
Previous owner had it since 1981 - chain and sprockets were done approximately 3000 miles ago - rear tire is newer than that.
It was a daily rider for him up until the year before last - ran until June of last year and was parked. I took it for a test ride less than a month ago. Both that and the ride back home were trouble free - then - the next ride - I started to get this weird cylinder skipping issue.
I suspected plugs - pulled all four and swapped them - all were black, but not so black that they weren't firing.
I ran a whole can of SeaFoam through it in a single tank - no appreciable difference.
I'm wondering if the whole thing can be explained by a piece of crud coming loose in the tank or fuel system and getting stuck in a carb.
Headed back down now to pull the plugs and see how the spark is.
I'll report back.
-Joey

**Guest** · 04-13-2011, 07:17 PM

Originally posted by SandPVRR

I'm wondering if the whole thing can be explained by a piece of crud coming loose in the tank or fuel system and getting stuck in a carb.

It most absolutely can..
I'd start with a detailed carb cleaning and go from there.
Keep in mind, its not typical to build these carbs in a day or so. It takes most with one can of Berrymans 4 days to clean a set. Pay very close attention to detail and use proper fitting tools.
Everything you need is in Bass Cliffs post.

**7981GS** · 04-13-2011, 07:30 PM

Beautiful Skunk!
I'm certain that with Cliff's help she will be purring like a kitten soon.
Keep at it. They are wonderful bikes.

Daniel

**SandPVRR** · 04-13-2011, 08:05 PM

Update:
Just came upstairs from pulling all four spark plugs and replacing with new - these are brand new NGK B8ES plugs from my local NAPA. They have about 130 miles miles on them, and as you can see - they are black. If you look - Numbers three and four are the worst: https://picasaweb.google.com/lh/phot...eat=directlink

Question: perhaps its not the carbs - but some sort of ignition problem - or perhaps I need to go to a different plug - the manual I got from BassCliff's site (for a 1979) says I can go to either the B7 or B9 as needed. Thoughts?
I just put another set of plugs in and the bike started to behave exactly the same as before.
Thoughts???
-Joey
(Who is thinking the goal of making a daily rider out of a 33 year old 'Skunk' might not have been his brightest move)

**7981GS** · 04-13-2011, 08:12 PM

Have you cleaned ALL of the ground wire connectors and their contact points?
How about the grounds that mount the coils to the frame?

Daniel

**Guest** · 04-13-2011, 08:13 PM

Clean the carbs according to the tutorial.

**steve murdoch** · 04-13-2011, 08:20 PM

I agree on the complete carb cleaning and you will have to address the crud in the tank.
The lazy rev return to idle in the video makes me think there might be an air leak as well. Hopefully new o-rings in the cleaning will help with that.

**JEEPRUSTY** · 04-13-2011, 08:21 PM

Originally posted by SandPVRR

Update:
Just came upstairs from pulling all four spark plugs and replacing with new - these are brand new NGK B8ES plugs from my local NAPA. They have about 130 miles miles on them, and as you can see - they are black. If you look - Numbers three and four are the worst: https://picasaweb.google.com/lh/phot...eat=directlink

Question: perhaps its not the carbs - but some sort of ignition problem - or perhaps I need to go to a different plug - the manual I got from BassCliff's site (for a 1979) says I can go to either the B7 or B9 as needed. Thoughts?
I just put another set of plugs in and the bike started to behave exactly the same as before.
Thoughts???
-Joey
(Who is thinking the goal of making a daily rider out of a 33 year old 'Skunk' might not have been his brightest move)

Well I do not know if they will reach but you could obivate the ignition bits by swapping the wire from cyls 2 and three. Thye are connected to the same coil and fire in a lost spark arrangment.

If the cold pipe moves from 3 to two it may be a simple bad plug cap.

Maine eh. Nice use of the media. I have never seen it done on here for this sort of thing.

**Big T** · 04-13-2011, 08:39 PM

The plugs are not the issue, stay with the B8ES - they are black because you're running it with the choke on

If the #3 cylinder is the one that's not firing (start it up again, let it warm up, hold your bare hand close to the pipes), you probably have petcock failure. Check the oil level to make sure that the crankcase isn't full of gas

The ignition is the 1st suspect - new points and especially condensors are called for (ask Scudder)

Then, a valve adjustment - not because it's part of the problem, but if you don't know when it was last done, it needs to be done

Then, clean the carbs - see the VM carb cleaning on BassCliff's site, get some new O rings

Sync the carbs and you should be good to go-barring other issues, like carb boots or tires (they may be too old)

The crappy throttle response in your video is most likely due to a combination of ignition and fuel issues causing it to run on 3 cylinders - but it should run better on 3 than yours does, that's why I suspect the ignition components

**SandPVRR** · 04-13-2011, 08:42 PM

Yup - from Maine - Ayuh. :-)
According to a couple other people who have seen those plug ends - #3 appears to be running to LEAN - anyone want to confirm / deny / suggest?
Just pulled the air box completely out of the bike and started it - issues remain, if anything slightly worse do to the lean running - bike was popping even worse than before.
Air cleaner looks ok -older - but clean on both sides and no obvious holes - one thing was certain however, it was not securely fastened into that plastic air manifold - It came out too easily for that. It will be securely in there momentarily - as I run down stairs and put the bike back together.
As to the compliment on the 'use of the media' - well - if you're going to explain what a bike is doing in words -why not break out the camera and video it backfiring instead of trying to explain it.
Quick question: Am I doing the bike any permanent or long term harm by riding it with it not at this 100% condition?
-Joey

**Guest** · 04-13-2011, 08:48 PM

Number three looks lean cause it aint firing. If the airbox and all the intake components arent sealed the bike wont run worth a crap. I still say ya need to go throught the entire intake system including but not limited to an entire full on carb cleaning. You can deny this all you want but untill ya do it, and know its done right you're just chasing your tail. You'll never make that bike run right no matter what ya do with dirty carbs.

**SandPVRR** · 04-13-2011, 09:03 PM

Update again:
Per Big T's suggestion - I put her on the center stand and looked at the oil level - either - she's burned about a quarter of a quart of oil since I did an oil change on 4/10 or the crankcase is filling with gas.
Two things point in that direction - one - there is a very strong gas smell when you pull all four plugs out and two - it appears to be using gas at an alarming rate - 58 miles since I filled it up and its only showing 1/3 on the gauge when on the center stand. (I haven't had it running in the garage that much!)
Can anyone recommend a petcock rebuild kit?
-Joey

1978 GS 1000 - Video Tech Support Request

1978 GS 1000 - Video Tech Support Request

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