Starting issue

im having a hard time getting my bike started. It seems to not be getting any fuel and my fuel line only seems to trickle fuel from the gas tank thru the line any ideas where i should look

 

What bike do you have?
Three position Petcock?
Refurbishing the Petcock would be a good start.
http://www.xjbikes.com/forums/index...ng-the-yamaha-vacuum-fuel-valve-w-pics.25058/

 

cap vent clogged pop open the cap see if flow improves
then what stumplifter stated

 

82 xj650 yes on the three position

 

Opened gas tank lid and no improvement so im leaning towards petcock now cause there seems to be no fuel going thru the line

 

Is this when the bike is running? Or when it is on prime filling the carbs? What condition is the vacuum line in that goes to the petcock?

 

Now im sorry guys im new at this so ill try to explain as best i can. When you say vacuum line im guessing the line that goes from #3 carb boot to the tank if so then it is a new rubber fuel line the same size as the old. However i dont have any clamps on the line. I cant even get the bike to start it acts like its starving for fuel

 

The petcock has three positions.
When standing on the left side of the motorcycle they are:

Reserve -------------Prime
------------- ON -------------

Prime is used to fill the float bowls after service, or long periods of sitting.
Turn it to prime and see if the float bowls fill so you can start it.
Turn it back to run once started and see if it keeps running for a while (it takes about five minutes of idling to run the bowls dry); alternatively you can unhook the fuel line, unhook the vac line from #3 and suck on it. I fuel flows you are good to go.

Based on your description of only getting a trickle of fuel you either have an obstruction in the fuel line or petcock, or you have a faulty vacuum valve (in which case you should rebuild or replace the petcock)

 

so you have set the petcock to prime and you are getting low to no flow of fuel?

the vacuum line must vacuum line not fuel line also. is will be a smaller dia than fuel line.

clamp the fuel line clamp vacuum lines if you lose vacuum your fuel will not flow except in prime

 

Or you have junk clogging the screens on top of the petcock---

On prime, it should flow quite freely and full stream

 

When it is on prime there is little to know fuel getting in. I don't have my vacuum line clamped down its just on both ends. I have a see thru fuel filter on the bike and it will barely fill half way. I will clamp down both sides just to make sure tonight and go from there is anything ill rebuild the petcock tonight. Also when I would wiggle the fuel line so some fuel would go down the line it sputter alittle like it was going to start but never fully does

 

Is the fuel line kinked anywhere? I once had to limp home with one hand on the throttle and 1 hand reaching under the tank and holding the line from kinking.

 

I don't think the line is kinked anywhere but ill look for that later tonight too.

 

Switch the vacuum hose to another carb (be sure to cap off #3). See if that changes anything.

Gary H.

 

Well i took the petcock off and was inspecting everything and the petcock diaphragm fell apart in my hand so i may need to rebuild it

 

Imo rebuild the gas cap while you're at it.

Gary H.

 

I was just going to buy a new one

 

The gas cap is eays to rebuild, so is the petcock. Buying new is an affordable alternative for the petcock, but not for the gas cap if yours is cosmeticaly in good condition.

 

hehe... kinky hose

 

I am going to rebuild the petcock but I was going to buy a new gas cap

 

If you can rebuild a petcock you can rebuild the cap. New gas caps are somewhere north of $80, and unless the gasket is bad you probably just need to disassemble yours to clean and lube it. The vent balls tend to get stuck after a few decades, but don't always need to be replaced.

Petcock rebuild instructions

Gas cap repair info

 

Sorry to post this here, I don't mean to intrude on someone else's post. Reading through all the posts a few have mentioned rebuilding the gas cap. I've never heard of that before, can someone explain what is in the gas cap that gets rebuild and how that works. Thanks!

 

Click the second link in my message above.

 

I just saw that, I'll have to look at it when I get home because I know I smell a little gas when I park in my garage an come back out a few minutes later. Is there a rebuild kit I could buy, like a petcock rebuild kit but for a gas cap?

 

Yes. Send a private message to user Chacal. His catalog is linked at the top right of every page.

 

Awesome thanks!!

 

Ok im still lost i rebuilt the petcock and still no fuel flow and i opened the cap and no fuel flow.

 

Ok so i can get it to start but only when i spray statring flued in the air cleaners

 

I know we're focusing on your fuel flow right now, but have your valves been spec'd and are your carbs clean? This seems to be the root of a lot of XJ issues. It still won't address the trickle of fuel, though... As for that, if it's not the tank vent, and it's not the petcock, could you have a blocked or kinked fuel line? Any fuel filters on it? They might be clogged. After you've gotten it started, does it keep on running, or just die out once the starter fluid burns off?

 

Getting the float bowls to fill when they are dry can be a bugger sometimes (on any bike).
First confirm that the petcock is passing fuel by taking the fuel line off and setting the petcock to prime.
If that test passes then hook the fule line back up to the carbs and open the float bowl drains (one at a time). That will help to get the fuel flowing.

If you still don't get any fuel in the float bowls I would revisit your floats (did they get installed upside down) and the float needles and seats (did you pull the seats to check for blocked screens?).

The onlt other possability I can think of is a blockage at the fuel inlet T.

 

Valves have been spec'd. I rebuilt the carbs about a month ago. The bike dies out when the starting fluid burns off. When the tank is off the bike i can turn the petcock to prime and it will flow. When the tank is on the bike and the vacuum line and the fuel line are hooked up i get nothing.

 

Would my float bowls being wrong keep fuel from even coming out of the tank?

 

No.
Let me ask this.
Are you trying to start the bike with the petcock set to ON?

Empty bowls need to be primed first. Set the petcock to prime and count to 30. Then try to start it. (also open at least one bowl drain to see if you are getting fuel in the bowl).

 

I do set the petcock to prime and nothing comes out of the fuel line. I have a see thru fuel filter and there is no fuel even filling the filter

 

I open number 2 drain plug and it is wet in there but nothing drained out. I open number 1 drain plug and fuel did drain out of it

 

What filter did you use?
Take it off and see if you get fuel then.
If not then revisit how you put the petcock together.

 

This filter and thats is the most it fills up. And thats with the petcock on prime

 

There's your problem. Most paper filters will not work with a gravity feed system. The air buble in there is also a not good thing. Start a conversation with Chacal and he can get you a small filter that has a sintered bronze element that will not restrict fuel flow.

I'm assuming that you did pull the filter off and found that you had good flow with the petcock on prime.

 

I took the filter off and i got good flow but now i cant see if its flowing and i cant get it started. I think my fuel line where it goes into the carbs could be clogged

 

I taken the drain plugs out of the bowls and im not getting any fuel to #2 #3#4 carbs. #1 bowl has fuel in it

 

Like k-moe said...if you open #1 drain screw and it's flowing nicely then open #4 (close #1 of course) and it's flowing nicely it's not the fuel flow into the rack.

Gary H.

Then it's the flow between the carbs.

 

# 4 has no fuel. I think its the fuel flow rack to and to be completely honest with everyone inever cleaned the fuel flow rack so i guess im pulling carbs off now and cleaning those