fuel and vacuum line placement 81 GS250

[mickey4810]

Hi everyone!

First I'd like to say thank you for letting me join this great resources for GS owners!

I'm a new GS owner... A neighbor gave me the bike and after checking it over I found it did not have the vacuum or fuel lines connected.

I bought a Haynes book for the bike and it's helped a little but I cant figure out where each line goes.

I found a T and think it goes to the main tank but I can not get fuel to flow through it.

I think I found the reserve tank line too and the bike will run if gas is poured through it.

Can anyone out there help me out with this?

Thanks again for letting me join and I look forward to being an active member once I get the bike running.

Mike F in Schenectady, NY

[Peppermint Patti]

You will probably get the help you need, if you move this question to the technical section.
That's where all the smart mechanic's hang out ( I think. ):roll:

In any case, welcome to the GSR, I see this is your first post.
Try posting in the correct sections...They're all great !\\/

[arveejay]

Welcome aboard. The valve on the tank has 2 fittings, I assume. Note they are a little dif. in size. 1 is a little bigger around than the other. I've never seen a 250 but I'm assuming they are the same valves. The smaller nipple which should be the back one, is a vacuum port and should hook up to one of the carbs towards the front of the carbs, The bigger nipple is for fuel delivery to the carbs and should hook up to the T which is inbetween the carbs. If the valve is set to prime, fuel should flow, if set to run or reserve it won't flow fuel unless the engine is running. In the TIPS SECTION is an article called,,( How to test a vacuum petcock). Read that and do the tests to determine the fuel valve is operating correctly.

[mickey4810]

fuel and vacuum line

Thanks for the replies!!!!!!!

Ok, I put a clear gas line on the T... There is gas in the line but when I crank the starter over the gas does not move and the engine does not start.

It only starts when gas is put in the smaller port (Vacuum)...

I'm assuming I'll have to rebuild the carb at this point. Does anyone know where I can get a carb kit for the bike?

[Nessism]

Motorcycle carbs don't need a "carb kit" like a automotive carb. You need to carefully take them apart paying particular attention to the low speed circuits in the carbs since these circuits have very small orifices which are easily clogged. You may want to buy what is commonly called an O-ring kit since these are the parts most likely to need replacement. Check ebay or the do a search here for carb O-rings.

Ed

[kalessin]

Thanks for the replies!!!!!!!

Ok, I put a clear gas line on the T... There is gas in the line but when I crank the starter over the gas does not move and the engine does not start.

It only starts when gas is put in the smaller port (Vacuum)...

I'm assuming I'll have to rebuild the carb at this point. Does anyone know where I can get a carb kit for the bike?

The petcock needs vacuum to flow gas to the carbs. If the carbs don't have gas in them, then they need to be "primed", that is, to have gas come down from the tank to fill the bowls at the bottom of the carbs.

If your petcock has a "PRI" setting, then turn it to "PRI" for a minute, then try starting. If you can get the bike started and gas doesn't flow when the petcock is set to "ON" "RUN" or "RES" (it may not have all markings), then you need to rebuild or replace the petcock.

[mickey4810]

The fuel lines again.

Right now I don't have the gas tank on the bike, I just have the clear hose.

The clear hose is about a foot long sticking straight up from the T and has gas in it!

I'm thinking maybe the T is cloged or something... But when I check it it's OK.

Can someone take a picture of their carbs and where the hoses go and maybe I could copy that for mine?

Once I get the hoses on correctly, if it still wont start then I'll go from there.

Thing is, when I had gas going into the vacuum port on the carb it DID start so I'm thinking there is nothing wrong with the carbs themselves.

[arveejay]

You can take the bolt from the bottom of the carb bowls and gas should flow out each of them. If you have gas in the tube and it won't come out of the bowl drains then your float valves are probably stuck or plugged. If the bike sat for a while, (several years) the carbs surely need cleaned, thoroughly.

[arveejay]

Thing is, when I had gas going into the vacuum port on the carb it DID start so I'm thinking there is nothing wrong with the carbs themselves.

When you put gas into the vacuum port, it's just dumping raw gas into that cylinder, I wouldn't recommend doing that.

[mickey4810]

Ok, I've removed the carbs and am waiting for a wind less day to take them apart... God Help Me! [-o<

Is there anything I should know before I do this?

I've rebuilt carbs on cars and a golf cart (Harley Davidson) but never on a bike.

This has to be gummed up... No gas came out when I removed the screws on the bottom.

And thanks for the warning about the fuel in the vacuum port!

[arveejay]

At the bottom of the page is Home page. Goto carb clean up instructional. You will need a set of O Rings from www.motorcycleorings.com