Bought a used GS750ES and could use some help with it.

[KRT]

Hey forum, a few days ago I bought a used 1983 GS750ES as my first motorcycle, and it needs a little work. The bike looks sounds and smells like its running rich. Im not mechanically inclined so I dont know what this could be, or how to fix it. Also, with the choke all the way in the bike idles at 2,000 rpm. Theres also an aftermarket yoshimura muffler on the bike, and I dont know if any other modifications have been made.


My second question is in regards to panniers, or how you guys would go about mounting a bicycle rack to the bike. Are there panniers for the bike, or just universal saddle bags I can get for the bike? I know theres a guy who used to make bike racks in Oregon, but looks like he one-offs the the mounting points to every bike so Id need to go to oregon for that.

[BassCliff]

Hey howdy hey!

Mr. KRT,

Let it be known that on this day you are cordially and formally welcomed to the GSR Forum as a Junior Member in good standing with all the rights and privileges thereof. Let it further be known that you can improve your good standing with pictures (not you, your bike)! :-D

As for getting it running right, the normal procedure is to adjust your valve clearances while you clean up and rebuild your carbs. Then use a Morgan Colortune and a Morgan Carbtune to adjust and balance your carburetors. Of course, don't forget to brush up on the charging system of your bike by getting familiar with The Stator Papers.

There are other ways to tweak your carbs, highest rpm method, plug chop method, etc. There's tons of information in the forum available with the search function. But if you can't find what your looking for, feel free to ask.

You should have an idle adjustment knob in between the #2 and #3 carburetors on the back side. Turn it to get about 1050 rpm at idle (+/- 100 rpm).

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff
(The unofficial GSR greeter)

[mriddle]

Mr. KRT,

Let it be known that on this day you are cordially and formally welcomed to the GSR Forum as a Junior Member in good standing with all the rights and privileges thereof. Let it further be known that you can improve your good standing with pictures (not you, your bike)! :-D

As for getting it running right, the normal procedure is to adjust your valve clearances while you clean up and rebuild your carbs. Then use a Morgan Colortune and a Morgan Carbtune to adjust and balance your carburetors. Of course, don't forget to brush up on the charging system of your bike by getting familiar with The Stator Papers.

There are other ways to tweak your carbs, highest rpm method, plug chop method, etc. There's tons of information in the forum available with the search function. But if you can't find what your looking for, feel free to ask.

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff
(The unofficial GSR greeter)

Welcome to the forum KRT ..

Lots of folks here who like to help.

BassCliff .. you are on top of it today as usual.


Mike

[spyug]

Your statement about the bike running rich is a lttle vague and you don't provide enough information for us to provide any meaningful input.

Firstly what makes you think it is running rich? Looks, sounds and smells? Could you please provide more detail.

Running at 2000 rpm with the choke in doesn't mean much other than idle maybe set too high and or the airmixture screws are too far out, or both.

How many miles on the bike? Does it have a stock airbox or does it have pod filters? Do you know if it was rejetted above stock? If it has an after market exhaust it could have had the carbs rejetted.

If you can provide more input perhaps we can help.

Cheers,
Spyug.

[Dave8338]

With an after market pipe on it, the PO may have rejetted it to compensate and went too large on the jets. With the bike sticking on 2000RPM's a idle, it is either an adjustment or intake o-rings that are in need of replacement. The only way to find out is to first play with the idle adjustment knob under the carbs in the center of the rack. If that shows no sign of affect, it is a good chance that it is the o-rings.

Keep us posted and welcome to the best source of info on the web, for your bike!

[Suzuki mad]

Hi KRT.

A lot of knowledge on these pages but like a good book you need to know where to look to find what you want.

Its common for people to put after market 4-1 exhausts as there originals rot out. In doing so the bike runs rough so they change either the needle jet in the carb or adjust the mixture screw to compensate. If they go completely mad and remove the air box and filter, add some smaller filter to the backs of the carbs. This makes a big difference in the air/fuel mix to the engine. More carb work is done.

As your bike is a 1983 its likely somebody has played with it during its life.

Have you had any of the spark plugs out and had a look at the colour of them?
(This can show how the engine is running, either very lean or very rich.)

Look at the back of the carbs do they have short individual filters or four short peices of what looks like rubber pipe that goes into a large black box with a single filter in?

Look around the carbs. At the front you will see four rubber mounts that go between the engine and the carb body. Is there any signs of leaks or damage to the ruber boots?

Have a look at the top of the carbs. Inbetween the engine and the carb close to the main body of the carb you should see a single brass screw for each carb body. Do these looks damaged or marked? (Don't play with them.)

Have you done a compression check on the engine?

This might give a few of the others some of the answers so they may be able to help you.

Suzuki mad.

[KRT]

Have you had any of the spark plugs out and had a look at the colour of them?
(This can show how the engine is running, either very lean or very rich.)

I'm not at all mechanically inclined so I'm a little weary of going into the engine at the moment.

Look at the back of the carbs do they have short individual filters or four short peices of what looks like rubber pipe that goes into a large black box with a single filter in?

Looks like its a single filter.

Look around the carbs. At the front you will see four rubber mounts that go between the engine and the carb body. Is there any signs of leaks or damage to the ruber boots?

The bike hasn't been cleaned it seems in years so everything is pretty greasy so if something's leaking its not obvious where it's coming from. The boots look clean dry and undamaged, however.

Have a look at the top of the carbs. Inbetween the engine and the carb close to the main body of the carb you should see a single brass screw for each carb body. Do these looks damaged or marked? (Don't play with them.)

On the top of the carbs in between the engine and the carbs, all I can see are two screws holding cable housing and keeping tension for... one I'm guessing is the trottle and the other one i dunno. The only brass screw I can see is in between carbs 2 and 3, facing the filter, with a knob at the end of it. Nothing at all looks damagaged or marked.

Have you done a compression check on the engine?

Nope. What's that?

[KRT]

Your statement about the bike running rich is a lttle vague and you don't provide enough information for us to provide any meaningful input.

The bike smells like gas. The idle is rough sounds to me like the engine isn't burning the fuel completly.

[TheCafeKid]

Heya KRT...Welcome to the forum..

Now..on to the tough stuff...If you yourself say you are not mechanically inclined, what inclines you to think that you are running rich? Im not trying to be rude or snobbish at all, but motorcycles are very sensitive when it comes to the air/fuel mixture. Running rich or lean can eventually cause serious damage to the valves, piston and rings and cylinder walls themselves. If you wish to learn how to work on your bike (which i would suggest, as the shops tend to not want to work on these old girls, and the ones that do will rape your wallet.) I would suggest first thing, right off find yourself a Clymer manual for your model of bike. Check www.Z1Enterprises.com or even ebay...they can usually be had a bit cheaper there. That manual will be the bible as far as working on your bike goes, and they are usually pretty thorough. Plus there are lots of people on here willing to help you out as well. But without the manual it will make it tough for you to know what we are talking about when we try to explain things to you. If you dont want to learn to work on it, i would suggest trying to find a shop nearby that will, and take it to them for their suggestions and perhaps a quote..then you can even bring that info here, and most can tell you whether they are trying to rip you off or not...IF you choose to work on it, get the manual and give us a shout!!

Good luck!
TCK

[TheCafeKid]

The bike smells like gas. The idle is rough sounds to me like the engine isn't burning the fuel completly.

Rich running can be cause by a fair amount of different things. What most here would suggest right off is to check the following on your bike before you can pin it down to one thing...again a manual will help you tremendously here.

Valve clearances are in spec
Airbox is sealed well and is not leaking air
Intake boots and intake boot Orings are in good shape and not leaking
Carbs are properly jetted and float levels are correct
Proper spark is getting to each cylinder, completing the burn and timing is correct.
Check your plugs for fouling (carbon buildup, wet, gassy plugs, burnt plugs, bridged plugs, oily plugs are all signs that can point you in the correct direction to find the cause of your problem)
Ensure that each plug cap is passing current to the plugs...

These are just some starting points...they may not neccessarily fix your problem, but they will help you in finding the actual cause..

[KRT]

found a service manual, which has been a great help, except I can't get the idle adjustment screw to budge. It's jammed and wont turn at all, and the service manual says i've gotta adjust it when the engine's hot. Even if it wasnt stuck I don't see how turning it is possible without burning my hand and arm on the carbs.

Anyone have any advice?