Dead Bike = sad day

howdy xj'ers, I know some of you say you would rather push a yamaha than ride a harley...but how far have you pushed a yamaha.

I went on a little 100+ mile ride a few days ago to test out my new grips. From the start i was noticing less power under 5000 rpms and not till that point would it really kick in. It got worse and worse till i could barely pull out of a stop. Ya, i should have stopped ridding but i was far from home. so on the return trip coming down a long hill i wasnt really using much throttle and when it finnaly came to give it some juice nothing happened. I pulled over hoping it was just hot and the bike was dead as soon as i pulled in the clutch. let it cool, no start, let it cool, tried to bumb start, sat on it, called a tow truck. So now its back home.

It has spark, and after a good n' fast bump i got it rolling under its own power, in first gear, at a bajillion rpm. as soon as i dipped down it shut off. In my yard i grabbed the exhaust. 3/4 pipes are hot, 2 is warm, 1 is cold, brrr.

Pulled the carb drain plug on 1 and no fuel? pryed at 2 and tottaly stuck.
The carb is off now but it isnt really dirty. especially the float pin, it looked fine. so Im gonna give it a good cleaning anyway and see what happens.

And the walking part, im currently moving about a mile away and have no acces to a truck xj's just dont have the same power without a carb.
Anyway, the big question is, what should i be looking for in the carb, and could it be anything else. This will all have to added to a checklist and taking care of next week but im just thinking ahead. moving is hectic
Thanks

 

Sounds like you ran out of gas

No...but seriously, If the carbs are dry that's a good place to start.

I'd pull the fuel hose of the petcock and turn it to Prime to see if the screen in the tank is all plugged up.
Does it have an in-line filter (check if that is plugged)
If those two check out and you get good flow of fuel with it on prime, I'd put the petcock back to "on" and apply some vacuum to the other side and see if it opens. Sucking on the hose should open it, but not recommended...it's never fun to suck on a fuel line!
Also check the vacuum line for cracks or if it was kinked. If it collapses it won't open the petcock and you'll "run out of gas"

Also if you have good flow in prime, go ahead and try to run it in prime. When I first got X1 the P.O. had removed the vacuum line and you had to run it in prime all the time.

If you have good fuel supply to the carbs then it's possible that your needle valve is stuck but NOT very likely.
I don't think you have a filter screen above the needle valve like the mikuni carbs do so that shouldn't be the problem.

 

Hi mike, so my carbs do have a screen, they are good. I should have put the petcock on "prime". doh! and checked what happened but the in-line fuel filter isnt clogged and the other carb bowls had fuel. getting fuel to the carbs isnt a problem its just that one bowl?
Im thinking maybe a block inside the carb where the fuel runs to all the bowls? its a big channel but who knows, i'll take a peak tommarow

 

if it's one mostly, I would venture to say a float is sticking. a little 1000 grit on the needle and bore should take care of it.

 

Dryed gas or crud in the tee and carb bodys where the fuel goes before the needle and seats above the floats. This area in the carbs is one of the most overlooked passage because people are afraid to "break" the rack. So if you are brave enough to take the rack apart you might want to replace the throttle shaft seals or at least check to see if they are not rock hard and leaking air where the carbs should not be pulling air from.

Good Luck
MN

 

I had this same problem on my XJ550 right after I bought it. It turned out that one of the battery cables was coming loose. The damn thing made me breakdown in traffic in the middle of the city... The bike's voltmeter even showed that I had voltage, but the bike kept getting progressively worse at low rpm, even though it would run just fine at high rpm. My guess is that it ran fine at high rpm because the bike could run off of the electrical energy that the engine produced when at high rpm and could NOT run off of the battery's energy at low rpm.

After tightening it, it ran fine.... until it happened AGAIN in traffic.... After installing some lock washers, I've never had a problem since. Best wishes on success, man.

 

hm. good suggestions.I think i'll grab some sand paper. tighten my battery. and consider MN's suggestion. I was really hoping to ride out the rest of the summer and spent the winter months in the garage but I guess If a mediocre cleaning wont do the job i'll have to follow MN Maxim. thanks guys

 

Dumb question, but is your tank sealed? If the screen in the petcock and/or the carbs are crudded up to the point of being starved for fuel, it's a good possibility that if it isn't, that's where the crud came from. Learned the lesson of sealing the gas tank FIRST the hard way on my '81 Seca 750. It was my first bike, I didn't know a lot, and bought it non running. Took the carbs out, cleaned and rebuilt them, and it ran GREAT! . . . for about a week. Then it started behaving much as you're describing. That's when I learned about fuel tank sealing . O.K., laugh at me all you want, like I said, I was about 20 years old, and didn't know much at all about bikes! Anyway, just a thought!