1979 GS1000E Engine vibration with rpm

[Guest]

Hello everyone I am new here. I have fairly good mechanical knowledge just not allot of experience with this bike and am looking to learn everything that I can.
I have a 1979 GS1000E I believe it is an (E) at least.
The bike runs quite nice although before insuring for the summer I will be opening it up to check the valve clearances, and changing the carb boot o-rings as I have not done this and do not know the condition of them.

My main concern is that as rpm rises the engine vibrates worse and worse. Just a 45 min ride and my hands start feeling numb on the highway.
I am looking for opinions on what may be causing the issue, I have not opened up the engine far enough to see if the clutch basket maybe has a busted off piece causing an imbalance or anything like that but other than that I am not sure what would cause it.
Note- the vibration does pretty much go away when the clutch is pulled in and rpm drops to idle while riding.

I have also noticed the plugs are quite fouled up with some carbon build up on them (to rich) the plugs are NGK-BR7ES. I do not know if the carbs have been re-jetted in the past or if they are even stock carbs or not I am currently at 1250ft above sea level. On the bikecliff page I am seeing that I should be running NGK B8ES can anyone verify this for the GS1000 instead of the 850?

Thank you for your help it is very much appreciated
Shawn Smith.

[Rob S.]

We'd love to see some photos, but perhaps more important is some information. What is your tach reading at 60 mph?

How many teeth on front and rear sprockets? How are the steering and swing arm bushings/bearings? Do you have a steering dampener installed?

New problem or new bike?

[Rijko]

Welcome Shawn,

the maintenance you put off doing may just solve the complaint.
This issue is sometimes caused by dirty and unsynchronized carbs and/or valve timing.

But since you say :

Note- the vibration does pretty much go away when the clutch is pulled in and rpm drops to idle while riding.

the GS1000 has a weak clutch setup.
The central clutch hub nut tends to come loose which causes a rumbling sound.
The springs incorporated in the backplate of the clutch hub get short over time, causing a rinkling sound.

I suggest you pull the clutch cover to check, even if just for peace of mind.

[Rijko]

On the bikecliff page I am seeing that I should be running NGK B8ES can anyone verify this for the GS1000 instead of the 850?

On there, you can find a GS1000 Service manual.
Download it, you'll find it useful when working on the bike.

In that manual you'll find the spark plugs specified : NGK B8ES or Nippon Denso W24ES.

[steve murdoch]

Welcome to the site, Shawn.
Agree with Rijko, carbs that have not been synched can cause an awful clutch racket/rattle. Which could lead to a vibration/buzziness.

If your plugs are carboned up and you do not know what jets are in the carbs it would probably be a good idea to do a complete cleaning.

[Big T]

Here's what you absolutely need to do to your bike

https://www.thegsresources.com/_forum/showthread.php?171846-Top-10-Newbie-Mistakes&highlight=top%20newbie%20mistakes

Here's how you do it

http://members.dslextreme.com/users/bikecliff/

Download the factory service manual and read the VM carb cleaning guide

[Steve]

As already mentioned, get the basics taken care of first, then attend to the details.

Check valve clearances. If the cylinders are not breathing approximately the same amount of air, the difference in the power from one cylinder to the next can definitely induce a vibration.

AFTER the valve clearance is done, sync the carbs. This will ensure that each cylinder is able to breathe the same amount of air through its carb, giving the same amount of power.

If those two don't help, go a little more 'exotic' with the diagnosis. I worked on one 1000 several years ago. Valve adjustment was perfect, carb sync was perfect. Had a slight roughness at idle, but not too bad. When adding some throttle, it just shook. Felt like a plug wire was pulled and it was running on three cylinders. After verifying spark on all four plugs, I checked ignition timing. The points for #2 and #3 opened and created spark perfectly. The other set of points actually opened and created spark at the right time, too, but only #4 was there at the right time, too. By putting a pencil through the spark plug hole and comparing #1 and #4, we found that #1 was getting to top dead center several degrees (about 15-20 or so) after #4, indicating a twisted crank. Hopefully that has not happened to yours.

Your spark plugs should be B8ES. The BR7ES is a hotter plug. Somebody might have installed it to burn off deposits that were making the plugs darker. If that was the case, it would be better to fix WHY there were deposits on the plugs, instead of applying a Band-Aid. There is also the possibility that someone thought that "hotter" plugs created a hotter spark and made the engine run better. I have met a disturbing number of people that believe that myth.

Regarding the "R": There does need to be some resistance between the coil and the tip of the spark plug. There are three places that can provide the resistance: wires, plug caps, spark plugs. Stock wires are copper-core wires, no resistance. Stock plugs also have no resistance. The plug caps are designed with about 5kΩ resistance. If you have resistive (aftermarket) wires or resistor caps, you do not need resistive plugs. However, if you have copper wires (stock) and non-resistor caps, go ahead and use BR8ES plugs.

.

[rphillips]

Shoot Steve, hoping nobody would need to bring up the twisted crankshaft thing, That's major.

[Big T]

While it can occur, it's pretty hard to twist a crank during normal use

Easy to test, remove 4 spark plugs, insert 4 plastic straws, rotate crank and see if they move up and down in pairs, 180 degrees apart

[TeamDar]

While it can occur, it's pretty hard to twist a crank during normal use

Easy to test, remove 4 spark plugs, insert 4 plastic straws, rotate crank and see if they move up and down in pairs, 180 degrees apart

You really just need to check the two outside cylinders, 1&4. If the cranks twisted anywhere it will show up.

[Steve]

Shoot Steve, hoping nobody would need to bring up the twisted crankshaft thing, That's major.

Well, I don't like to bring up the worst-possible scenario right away, at least I gave two options to try before having to resort to the crank possibility.

And at least I'm not guessing on this one, I have seen it for myself.

.

[rphillips]

Yep, rarely twisted under normal riding, but how many of these bikes, way back then, weren't hammered on pretty regularly, or at least occasionally? Let's quit talking about it, that probably ain't it anyway.

[Grimly]

Yep, rarely twisted under normal riding, but how many of these bikes, way back then, weren't hammered on pretty regularly, or at least occasionally? Let's quit talking about it, that probably ain't it anyway.

It happened often enough for Suzuki to weld the cranks on the bigger ones.
I also twisted an 850 one, during a cold start.

[rphillips]

Yes, started welding them, I think, in "83" on the 1100 & 1150's with the 16 V cylinder heads. I think they left one journal, at the primary gear, not welded not welded???. But did Suzuki weld the crankshafts on the 8 V engines, I just don't remember hearing anything about the factory welding the 8 V.

[shawnsmith]

Thank you everyone I will carry out the basic maintenance IE: valve clearances, carb cleaning and sync as well as identify the jet size and because it is an easy thing to check I will check if the crank is twisted (fingers crossed that it is not).
once I complete that I will post an update about if the vibration goes away or not.