[Kreylyn]

Possible reasons your bike is getting crappy milage...

1. Someone jetted it poorly and now it's stupid rich in the higher rpms when cruising along.
2. Floats are sticking and allowing fuel to drain/flood out into the airbox or crank case.
3. If someone worked on the carbs, they tuned them wrong/adjusted them wrong.
4. Sprockets were changed to way high and now the bike struggles for acceleration.

If your able to do any basic work on it at all... I would suggest...


-Check the carbs to verify if they are jetted, check the A/F screw settings (or if the caps are removed at all).
-Pull the carbs off the engine boots, hook them up to the gas tank and turn it to prime. Wait a couple of mins and see if any fuel is leaking anywhere.

From there... based upon the information you find... will go a long way in helping to resolve the issue you have.

Krey

[pavendort]

I too am getting somewhere around 25-28mpg. Ridden the bike thru about 5 tanks so far. Runs strong, and I cant smell gas... The guy I bought it from was a bit of a tool, but he SAID the work was done by a local shop for maintenance, and it was just serviced within 200 miles of him selling it. Not sure I buy that tho. I need to pull the carbs off and clean them and all that jazz. Problem is I know nothing about carbs at all. Not even a little bit!

[stonefry]

I found the problem. I started the bike and felt the individual exhaust pipes I thought one might have been cooler, but I wasn't completely sure. I rode it home and sprayed some water on them. Sure enough one of them didn't evaporate the water immediately. Next step, check the spark plugs? I have never actually take the tank off yet.

[phil823]

not hot....spark plugs, and wiring check!

[stonefry]

not hot....spark plugs, and wiring check!

Haven't gotten into it yet. On vacation. Will troubleshoot Sunday afternoon.

[stonefry]

Possible reasons your bike is getting crappy milage...

1. Someone jetted it poorly and now it's stupid rich in the higher rpms when cruising along.
2. Floats are sticking and allowing fuel to drain/flood out into the airbox or crank case.
3. If someone worked on the carbs, they tuned them wrong/adjusted them wrong.
4. Sprockets were changed to way high and now the bike struggles for acceleration.

If your able to do any basic work on it at all... I would suggest...


-Check the carbs to verify if they are jetted, check the A/F screw settings (or if the caps are removed at all).
-Pull the carbs off the engine boots, hook them up to the gas tank and turn it to prime. Wait a couple of mins and see if any fuel is leaking anywhere.

From there... based upon the information you find... will go a long way in helping to resolve the issue you have.

Krey

We did a valve adjustment and synced the carbs and the bike does run better now, but the mileage is only slightly better if at all. I have not gotten into the carbs yet and have not even taken them off the bike. I know that is the next step, but I am a little nervous to do it. I have a friend that is quite knowledgeable and willing to help, so we'll see how it goes.

The plug in the 3rd cylinder was black at the end (new plug) and there is a lot of soot around the exhaust pipe. I know there is a problem in that 3rd cylinder or carb, just don't know what it is yet. We verified that there is spark there, but he said it's yellow when it should probably be blue (any confirmation on that?).

Not knowing a whole lot about the specifics here, it just sounds like a whole bunch of fuel is getting dumped into the 3rd cylinder and not burning.

Any ideas?

Oh, the brass plugs were still there, so nobody has change the mixture screws and I doubt it's jetted for that reason. Didn't check for fuel leaks yet.

The idle wanders around all the time so I know I need to clean the carbs. Is it possible that that is all I need to do to fix the MPG situation?

[scottynoface]

Stuck float in the #3 carb.

[Kreylyn]

We did a valve adjustment and synced the carbs and the bike does run better now, but the mileage is only slightly better if at all. I have not gotten into the carbs yet and have not even taken them off the bike. I know that is the next step, but I am a little nervous to do it. I have a friend that is quite knowledgeable and willing to help, so we'll see how it goes.

The plug in the 3rd cylinder was black at the end (new plug) and there is a lot of soot around the exhaust pipe. I know there is a problem in that 3rd cylinder or carb, just don't know what it is yet. We verified that there is spark there, but he said it's yellow when it should probably be blue (any confirmation on that?).

Not knowing a whole lot about the specifics here, it just sounds like a whole bunch of fuel is getting dumped into the 3rd cylinder and not burning.

Any ideas?

Oh, the brass plugs were still there, so nobody has change the mixture screws and I doubt it's jetted for that reason. Didn't check for fuel leaks yet.

The idle wanders around all the time so I know I need to clean the carbs. Is it possible that that is all I need to do to fix the MPG situation?

Bouncy idle = vacuum leak. This would definately cause an issue. Need to track that down.

Black plug would definately be a sign too much fuel is present for that cylinder. I would check the float isn't sticking.

krey

[stonefry]

Bouncy idle = vacuum leak. This would definately cause an issue. Need to track that down.
krey

Let me explain this problem in more detail. I can come to a stop and it will idle at 1500. Ride a block and come to a stop and idle will be at 2k. rev it a little and it will come down to 1600. It doesn't jump around much, it's just inconsistent.

Also, what causes a stuck float? Am I going to have to clean the carbs anyway to get it working correctly?

[Tushaar]

I'm having the same problem. But i have 20mpg or even less.
Today i cleaned carbs and looked that they were synced. but forgot to check A/F screws. Will do it tomorrow. Spark plugs are black, not chocolate, under 5k rpms it makes noise like a chopper, bike wont go over 180 km/h and dies on 8k rpm at 180kmph on 6th gear.
black smoke emerges when suddenly accelerate on neutral :P

[scottynoface]

I'm having the same problem. But i have 20mpg or even less.
Today i cleaned carbs and looked that they were synced. but forgot to check A/F screws. Will do it tomorrow. Spark plugs are black, not chocolate, under 5k rpms it makes noise like a chopper, bike wont go over 180 km/h and dies on 8k rpm at 180kmph on 6th gear.
black smoke emerges when suddenly accelerate on neutral :P

You are somehow dumping way too much fuel into the engine. You most likely have the same issue as the OP.

[stonefry]

Ok, found the problem. Whomever took these carbs apart before I bought it decided that the jet pilot was not an important part and did not include it when reassembling it. Now to order the part and wait. Any advice on what else may have been damaged? Everythink looks ok to my eye.

[stonefry]

For future reference, it was not the pilot jet, it was the needle jet. The schematic for the 2004-2006 carbs has 3 parts that are labeled incorrectly.

[DreKat]

Throwing a can of seafoam in the tank wouldn't hurt anything either