Fuel issue

[D-Fuzz]

I have had a bit of a weird issue with my Tiger lately.  At around the 150-mile mark on a tank of fuel, the bike starts to bog, like it is starving for fuel.  I turn to reserve and the bike continues to run, but there is no power.  I can ride like that, but if I pull in the clutch, the engine dies.  I have to put the choke on to restart it and after a minute or so idling, I can continue on.  If I try to push it too hard, it does the same thing and dies.  This had happened on 3 separate occasions, always when riding at highway speeds.  I cleaned the tank out and removed the sock filters from the petcock already.  Is it just that it gets starved for fuel and has a hard time replenishing it once I switch to reserve?

[Mustang]

1. does your tiger whistle when you leave it in the sun , if no clogged tank vent . keep a spare key in the gas cap and when it does it open the cap.
if it instantly comes out of it and starts to run better you have a plugged air vent that vents thru the gas cap .

2. have you drained any fuel out when it;s on reserve .............could well have water in gas caused by plugged drain line that exits at right rear of tank . it lets rainwater drain that collects under the cap .

3. you could have a plugged filter that;s in the gas line where it attaches to the carbs between #2 & #3

4. coil failures feel a lot like carb trouble on these beasts

no power (and stalling) means one or more cylinders have given up either due to fuel supply or spark .

[CoolHandLuke]

Blow out the petcock too.  When I first bought my Tiger, I cleaned the filters in the tank and the inline filter near the carb and the problem persisted, but intermittently.  It turned out there was crap in the tap, which was odd, because I had checked that the petrol was flowing smoothly.  A quick blow through with air and the problem has never returned.

+1 for Mustang's list.

[D-Fuzz]

My Tiger does whistle (always wondered what that was from).  When I took the screens of the petcock tubes, I completely drained the tank, so water shouldn't be an issue.  That filter where it attaches to the carbs might be the issue, but wouldn't I experience similar problems regardless of how much fuel is in the tank?  I thought about the coils (hoping that isn't the problem) but today, prior to this happening, I was riding lower speeds on some dirt/gravel roads, so I would have thought that heatsoak from less air moving through the bike would cause the coils to crap out, but it seems to happen mostly at highway speeds.

[rybes]

carbs freezin praps ? i get similar prob on mine. i found usin 99 ron fuel cured it  

[D-Fuzz]

When I was out yesterday, it was about +20C, so that shouldn't be an issue.  Does it matter if I am running regular vs premium fuel?

I went out for a ride this morning, about 100 miles on a fresh tank of fuel and the bike ran great.  I am curious to see what happens when I get around the 120 miile mark.  Maybe it is time to run a little Seafoam through it again to make sure everything stay cleaned out.  I am supposed to be going on a ride through the Dakotas, Wyoming and Montana in mid-July (3000km in 4 days), so I really don't want to be fighting with this bike, if I can avoid it.  A set of Nology coils is on my list, just not for this year.

[Mustang]

have you or previous owner replaced the fuel hose from petcock to carbs?

I have seen it make fuel problems go away , just  a thought .

[D-Fuzz]

I haven't replaced it, but I do have a couple feet of fuel hose in the garage for when I have had to empty the tank, so I suppose that would be easy enough to do.  What do I have to remove from the bike to get at the end attached to the carbs?

[CoolHandLuke]

What do I have to remove from the bike to get at the end attached to the carbs?

   

Actually, you should get away with removing only the petrol tank.

Undo the side fairing bolts, the tank bolts, disconnect the fuel hose and fuel sensor (on the right behind the fairing) and you are good to go.  I usually remove all the fairings, because I like the clear space, but there is no need.

[Rocinante]

This sounds a lot like the problem I had a few years ago. It happened when I was driving fast over a period of time and the tank was maybe 1/3 full. The reason was a clogged tank vent that cause fuel starvation. If it is, then it should go away if you open and shut the tank filler cap.

[D-Fuzz]

Grrrrr

I went to start the bike this morning to ride to work.  The bike turned over, let out a rather loud backfire and a puff of black smoke, then started up.  I'm sure I had neighbours calling 911 thinking some "gangstas" had infiltrated the area.  I added a bit of Seafoam to the tank and stopped at the gas station on the way to work to fill up.  I am planning to take a good rip after work, hopefully to clean out any crap that might be in there.

[Mustang]

Grrrrr

....................let out a rather loud backfire and a puff of black smoke, then started up.  

this is caused by being jetted too friggin rich , no amount of spirited riding is going to "clean it out"

Your bike should have mikunis on it
105's for main jets
if you have #39 pilot jets set the screws at 2 turns out
#40 pilot jets set the screws at 1  1/4 turn out
needles should be in the middle notch
right hand snorkel plugged

if your mains are bigger than 105s you need to at least open the right hand snorkel up .
I think you have mentioned before that you have 110's or bigger for mains , that is too big of a main unless you ride around WOT all the time !

every bike behaves differently but the above recipe should get you real close to the magic setup.

[MtheTiger]

1. does your tiger whistle when you leave it in the sun , if no clogged tank vent . keep a spare key in the gas cap and when it does it open the cap.
if it instantly comes out of it and starts to run better you have a plugged air vent that vents thru the gas cap .

2. have you drained any fuel out when it;s on reserve .............could well have water in gas caused by plugged drain line that exits at right rear of tank . it lets rainwater drain that collects under the cap .

3. you could have a plugged filter that;s in the gas line where it attaches to the carbs between #2 & #3

4. coil failures feel a lot like carb trouble on these beasts

5. Check the inside of the tank by draining all left fuel....I had the same problem and it turned out to be a clogged reserve sieve...the petrol looked like milk  :shock:  :shock:  Apparently the inner coating in the tank was dissolved in the petrol ?!?!  A good rinse with fresh petrol and a new petcock did the trick.

[CoolHandLuke]

5. Check the inside of the tank by draining all left fuel....

What about the stuff on the right?


I'll get my coat...

[D-Fuzz]

Your bike should have mikunis on it
105's for main jets
if you have #39 pilot jets set the screws at 2 turns out
#40 pilot jets set the screws at 1  1/4 turn out
needles should be in the middle notch
right hand snorkel plugged

every bike behaves differently but the above recipe should get you real close to the magic setup.

Mr. Mustang knows his stuff!

I took my bike to a guy in town and had him do some dyno tuning with my bike, giving him these specs are a guideline to make improvements.  He did some "before" runs and the bike was way too rich at idle but tended to lean out as it got toward WOT.  Made sense as it smelled like pure fuel at idle.  He said the biggest problem was with the needle settings, but all-in-all it was pretty messed up.

Anyway, he used Mr. Mustang's guidelines, with a couple minor tweaks, and it is much better.  He did some dyno runs this afternoon and it came out at 71hp / 51ft lb at the rear wheel with a air-fuel ratio between 13.4-13.7.  For a bone stock Tiger, I can live with that.  I am just looking forward to getting some decent mileage, the rest is what it is.