Looking for some advice.

[courier11sec]

Hi folks. I joined this board a while back when I was looking to get a 1981 GS850G, but didn't end up getting it right then and then the weather turned and it sort of got pushed aside.
Well, now here I am getting ready to get the bike. Before I get started here, I did a search for "no start" and didn't see anything that shed any light on my situation.
It's been sitting a couple of years, so I had to get a new battery. I drained the old fuel out of the carbs, (the tank was empty), added fresh fuel and tried to start the bike. Seems to turn over just fine, but won't start. I've tried the petcock in all positions with no change. The plugs look plenty serviceable and the bike has spark. I've been a car guy for quite some time, built a few engines, plenty of carburetors etc, but I've never had a bike or worked on one before. I pulled off one of the air filters and was greeted by a carburetor that is completely bizarre and foriegn to me. The barrel inside that must take the place of the butterfly on automotive carburetors doesn't move when I twist the throttle. Are these vacuum operated or have I got a non-working throttle? For what it's worth, the throttle presents what seems to be a reasonable amount of resistance. Do these carburetors have a accellerator pump? Any common fundamentals a bike guy would know that a car guy probably wouldn't think of would be greatly appreciated.
I haven't tried starting fluid yet, but I probably will when I go back to where the bike is.
I believe the bike has about 20,000mi on it. Can't remember exactly.
Thanks very much,
-Ray

[Clone]

When you twist the throttle grip do the rear butterflies open (engine side)? To see if they do you will need to push the barrel up (from now on called "the slide"), the slides move up and down with vacuum from the engine, the throttle opens butterfly valves on the other side of the slides. Since you drained the carbs and refilled the tank, turn the petcock to "pri" = prime, this allows fuel to flow freely, get yourself one of your wife's prized cookie sheets to catch gas and remove one of the drain plugs from the bottom of a carb. Does gas come out? If not then the petcock is probably plugged and needs to be removed and the screen cleaned. If you get gas there, you have flow, now after turning it over pull a plug and see if it wmells of gas, if not you have to remove and clean the carbs.
Also if the plug smells of gas, pull them all, clean them put them back in, pull the choke, hold the throttle open(you need three hands for this) hit the starter and give it a shot of ether, sometimes a motor that has sat for a while will need a little help to get going the first time.
Hope this helps.
If not continue to ask questions and someone around here will offer better help than me.

[courier11sec]

Thanks. I'll try what you said. Hopefully that'll get it fired up. I've seen the bike run before and know it ran well. I'm sure it's just groggy from its long nap!
Thanks again.

[ruddy]

Two suggestions:

1. Get a service manual. A Clymer will do to get started. Check eBay.

2. Clean the carbs. Be sure to clean all three jets and their passages thoroughly. Make sure the floats and valves are clean and working freely. If you remove them as a set and don't separate them, you'll be able to replace them and get the bike running.

Welcome aboard!

[ccratin]

Second that. The pilot circuit, which is where the bike gets fuel for idling is likely stopped up. Are you putting the choke on when you attempt to start it?

Pull the fuel line from the petcock and put the petcock in the PRI position to see if fuel is flowing freely on PRI. If so, you know the carbs are in need of cleaning.

BTW, you may not need to buy anything for the carbs but o'rings. Cycleorings.com is the place to go, or you can try your local Suzi dealer. They will often have them if you are in a big hurry. Also, if you go to the GSR homepage, there is a link to the carb cleaning documentation. It is very helpful in learning the ins and outs of these carbs, which are much simpler than most automotive carbs by the way!

[DaveDanger]

courier11sec, Something helpful you may be interested in fabricating is a temporary tank. It'll help you quickly get fuel into your carbs while you troubleshoot your petcock and other parts and pieces. Look around your collection of automotive/lawnmower stuff and select that 1 gallon plastic gasoline container. Drill a small 1/4" dia. hole in the side of the container right at the bottom. Go by Home Depot or Lowes and get a 1/4" dia brass barbed fitting that's designed to go through a panel with a jam nut to lock it in place. Push the brass fitting through the hole in the fuel container and using a long pair of needle nose pliers or somesuch install the jam nut over an o-ring of appropriate size. Tighten the brass fitting. Push a clear vinyl tube of about 8' long over the barbed fitting and oila! you have a fuel tank that you can instantly connect to your carb inlet and not have to use a petcock of any sort. You can crank and run the engine as necessary with the tank completely removed. Just make sure and set the temporary tank on a bench or support that's higher than the carbs so that you have good gravity flow. When you're not using the tank, push a golf tee in the end of the hose and curl it around and through the can handle a few times to store it. When you're actually using the fuel can, insert the golf tee into the vacuum line that normally connects to the petcock.
If I manage to get the digital camera I'm bidding on from fleabay, I'll post a good pic of mine. Works great

[ruddy]

One more point: the pilot jet is under the rubber plug next to the main jet. Also, it's imperative to use a proper hollow ground screwdriver blade for this tiny jet. The jets are all soft brass, and you can easily ruin the screw slots if you're not careful. I use a set of gunsmithing screwdrivers for carb work, because they are some of the best around. A typical wedge shaped tip will not fit correctly.

[courier11sec]

You guys are the coolest. Thanks for all the replies. I'm going to spend an hour or so with the bike in the early part of the day tomorrow. Unfortunately I have to run down to Seattle for something, so I won't be able to spend the day on it. No carb rebuild for me tomorrow. Maybe this Sunday.

[AOD]

I drained the old fuel out of the carbs, (the tank was empty), added fresh fuel and tried to start the bike.

Clean those carbs.

[duaneage]

If it has sat a few years I would get the oil out of it and change the differential fluid in the rear. Make sure the level is up to the fill hole (or whatever the clymers calls for in volume).

The carbs work very much like vacuum operated secondaries on the Rochester 4-barrels. There are needles that raise with the slides to allow more fuel into the engine as engine speed (and vacuum) increases. the slides are raised by rubber diaphrams in the carb top. The slides may be stuck with varnish, use carb spray to clean them and make sure they raise up until they almost completely open the bores.

The Choke on these carbs relies on a small passage that pulls gas from the bowl through a tube and dumps it into the front of the carb near the butterfly valve. THere is no choke plate, it is a simple enrichment method. These choke circuits are notorious for clogging and making a GS hard to start.

The rubber manifold boots on the head have O-Rings which are probably bad. 1.71 a piece from the dealer + a few dollars worth of M5 19mm allen head bolts and you can replace them. The phillips head screws are hard to get off but the allen head bolts replace them just fine. Home Depot has the same size, take one along to compare. When you have the carbs off take advantage of the opportunity to change the O-Rings

Compared to other old bikes the GS is a real champ. There are few issues with the carbs and the voltage regulators need to be replaced with Honda models but your looking at a 100K mile engine and that is the truth.

Search for Honda Regulator Mod and see the other most important thing you can do (cheaply) to keep a GS on the road for a long time.

[courier11sec]

Thanks again. Didn't get to mess with the bike yesterday like I planned, but I'm hoping to get after it again on Sunday.

[courier11sec]

Didn't make it Sunday, but I went over Wednesday and got it running!
Petcock works fine, carbs were getting fuel. Turns out the choke cable is broken. A quick spritz of starting fluid and about a minute of babysitting the throttle and it was idling smoothly at around 5-600rpm. Had the guy I'm buying it from ride it to a big empty parking lot for me and got to try a few takeoffs and stops and one turnaround. Mind you I've never ridden a bike before. No stalls, no crashes! Woohoo!!!!! More as I get after it!

[ccratin]

Until you get a new cable, you can put a zip tie on the end of your choke rail and adjust it where you can use it as a pull to pull out the choke manually. That's what came on mine and I used it until I replaced the cable!