Clutch repaired, but carburetors- Uggggghhh!

[ThrottleJunky]

That's good but you missed the model etc. G , SG,

It's a standard, but I'm not sure if that means G, SG, or what.

[James England]

I just fitted in line filters. I bought these http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=170532135404

They are excellent quality. The body is chromed metal and the clear tube is glass. This means no discolouration (or discoloration) to the tube. They fit nicely in the fuel lines and there's enough space for them in the carbs/inlets/tubes area.

They're really top quality and allow plenty of feul through.

[ThrottleJunky]

Seeing how there is no dipstick, how am I to know if my oil is contaminated with gasoline? I guess I can assume, since the airbox was full, that it filled up the cylinder and got past the rings and made its way into the crankcase?

Also, what size diameter are the lines for the fuel filter? I see filters in 1/4", 5/16", and 3/8".

[James England]

Seeing how there is no dipstick, how am I to know if my oil is contaminated with gasoline? I guess I can assume, since the airbox was full, that it filled up the cylinder and got past the rings and made its way into the crankcase?

Also, what size diameter are the lines for the fuel filter? I see filters in 1/4", 5/16", and 3/8".

It's more likely that all the fuel has gone backwards into the air filter. On my 1979 carbs, the fuel ejected backwards through one of the holes under the carb mouth.

I used 8mm as per the eBay listing I put in my last message

[tinman905]

It's a standard, but I'm not sure if that means G, SG, or what.

That would be a "G" then .

[Ken Talbot]

Seeing how there is no dipstick, how am I to know if my oil is contaminated with gasoline?

Any old piece of stick will do. Poke it down the filler hole and remove it with a sample of oil. Take the stick and sample outside to see how it smells and flammable it is. The other good sign is if the oil level has come up way higher than full.

OTOH, were you just asking how to check the oil level? With the bike on the centrestand, the oil level should fall between the two lines in the sight glass on the lower right side of the engine.

[natemoen]

It is 1/4 inch fuel line. A lot of guys use 3/16 tygone fuel line though and then they do not use clamps.

There is a sight glass near the bottom rear of the clutch cover. That is how you check the oil level when the bike is on the center stand.

[tinman905]

[QUOTE=natemoen;310169]It is 1/4 inch fuel line. A lot of guys use 3/16 tygone fuel line though and then they do not use clamps.

There is a sight glass near the bottom rear of the clutch cover. That is how you check the oil level when the bike is on the center stand.[/QUO

I use Tygon fuel line and think it's a good pruduct . I don't use any clamps ,never had a fuel line fall off.

[James England]

Even the 1/4" doesn't come off.

[ThrottleJunky]

Thanks guys. No I was not asking how to check the oil level. I am familiar with the sight glass. I just stuck my nose near the filler area to see, and it smells a bit like fuel. I'll just change the oil again after I identify the problem. I'm really anxious to get this carb figured out.

Where do you guys recommend I buy carb parts? It seems that some may be better than others. I'm thinking I should opt for new needle/seat combos at the very minimum, and I also need some rebuild kits for the petcocks. I appreciate any info.

[tinman905]

Thanks guys. No I was not asking how to check the oil level. I am familiar with the sight glass. I just stuck my nose near the filler area to see, and it smells a bit like fuel. I'll just change the oil again after I identify the problem. I'm really anxious to get this carb figured out.

Where do you guys recommend I buy carb parts? It seems that some may be better than others. I'm thinking I should opt for new needle/seat combos at the very minimum, and I also need some rebuild kits for the petcocks. I appreciate any info.

This is one places , if you just buy the needles and seats you will pay just as much for the entire kit here.

http://cgi.ebay.ca/4-YAMAHA-1980-XS1...item53e5e4ef85

[ThrottleJunky]

This is one places , if you just buy the needles and seats you will pay just as much for the entire kit here.

http://cgi.ebay.ca/4-YAMAHA-1980-XS1...item53e5e4ef85

Is there differing quality in these kits? I see partsnmore has stuff, too, for around the same price.

[tinman905]

Is there differing quality in these kits? I see partsnmore has stuff, too, for around the same price.

I believe you will find it's all the same quality . It sounds like you really only need the float needles and seats so the rest is spare. georgefix has a good rep and has been around for a while . Up here he delivers faster and cheaper than Parts&more or other online stores .

[DGXSER]

Hey ThrottleJunky, like the others have suggested the issue is in your float system. The way the fuel system works is that the petcocks control IF fuel can flow TO the carbs. The float needle valves control how much fuel is let into the float bowls. If they do not stop the fuel when they should, if keeps filling up until it flows into the throat of the carbs and runs either back into the air box or forward into the engine, or both.

It is a good idea to trim the gaskets on the sides so they match the edges of the float bowls so the floats will not snag on them and get hung up.

Testing the floats is a two step process....maybe three. First test to do is when you have the floats assembled and set, before you put the bowls back on. Set up a fuel source to the carbs, and let the fuel flow into the Ts. The float valve should stop it from flowing. Now ever so slightly lift the floats to let a small amount of fuel through, and release. Now dry up the fuel using towels and compressed air or the like. Let them sit with the fuel "on". Go make a sandwich and eat it. When you come back, look for any signs of fuel leaking past the floats. If all is dry, move on to test two.

Now, put the bowls back on, and do the test Tinman suggested. Put them right side up. Nice and level just like on the bike and see if they leak.

Third and final is to mount them on the bike and turn the fuel on at the petcocks and wait a minute or two before you fire the bike up to see if they leak.

I had a set of carbs that would pass test one and two and then fail on test three over and over. Wound up my fuel line was the automotive stuff that has soft rubber inner liner. Well the Ts on the fuel lines would eat that rubber when I put them on and small pieces were getting into the carbs and keeping those seats from sealing, and with the line connecting to the Ts at the carbs, even in line filters would not prevent that.

Hope this helps.

[ThrottleJunky]

Thank you all for the replies. The carbs will be coming off, again, and I will let you know what I find. The leaking petcock needs to be fixed, too.