only getting 60 mpg By seanstr (Read 2,133 times)

[seanstr]

I purchased, New, a 2013 cali classic 125 cc scooter in 2012. In June of 2013 I took it in to shop for many things. The only thing they really did was make it worse and replaced the carb. This was in my opinion the only positive thing done to scooter.

My problem: scooter still only gets 60 mpg. I have a new air filter in. Just changed oil. New belt and a set of sliders and rollers (13 g sliders & 14 g rollers) all from Dr pulley. It drives great, but I can't get the gas mileage to go back up.

I have taken the seat off and used my lighted mirror to get a good look at carb from all sides. No leaks while running scooter. It's supposed to be a completely new carb. So, what is left that could cause this.

Maybe fuel line coming from tank?

Is there anything else?

[rks]

You didn't say what kind of mileage you used to get. Did it get better mpg before you made mods to the drivetrain?...Mileage is largely determined by driving style. If most of your riding is stop light to stop light, or if you are running mostly highways, and trying to keep up with 55 mph traffic, then maybe you can't expect more than 60 mpg. Have you pulled your spark plug to see if you are running excessively rich? ... Think that's where I'd start...Lots of variables...

[seanstr]

Aug 25, 2014 6:40:08 GMT -6 rks said:

You didn't say what kind of mileage you used to get. Did it get better mpg before you made mods to the drivetrain?...Mileage is largely determined by driving style. If most of your riding is stop light to stop light, or if you are running mostly highways, and trying to keep up with 55 mph traffic, then maybe you can't expect more than 60 mpg. Have you pulled your spark plug to see if you are running excessively rich? ... Think that's where I'd start...Lots of variables...

No, the gas mileage was 60 mpg. It used to get 80+mpg. Then I took it to shop. It still isn't getting better than 60 mpg.

I looked for leaks in gas line, nothing, looked for issue with fuel filter.

I had to retap/rethread the right side exhaust bolt.

So, this is my question? Can a minor exhaust leak that is undetectable with the ear cause bad mileage?

[gatekeeper]

Look at your spark plug to see if it is running excessively rich. If it is fine tune the carburetor. if it is running too rich it could also be that the petcock is failing and allowing some fuel to run down the vacuum line into the intake manifold. You can check that by pulling the vacuum line off of the nipple on the intake manifold and looking to see if any fuel dribbles out when suction is applied.

[rks]

seanstr said "So, this is my question? Can a minor exhaust leak that is undetectable with the ear cause bad mileage?"

Answer: No

If you are only averaging 60 mpg, on many, many consecutive tank fills, and you are sure you are not loosing any to leaks or vandals....then you must be using it.
Do you know what your original variator weights were? I'm still confused by your statement about what you have now....13gr...14gr....rollers...sliders
Have you checked brake temps after driving scooter...is one dragging a bit...(don't get burned when doing this)
Have you done anything to the clutch? Cleaned out the belt dust...checked pads for glazing....maybe it's slipping some
Do you have a tach installed?.....It would tell you if the rpm's at your normal cruise speed have increased.

Still say pull the spark plug first...if it is covered with cartbon....it's getting too much fuel

Read this thread:

scooterdoc.proboards.com/thread/10488/long-ngk-c7hsa-last

[seanstr]

Aug 25, 2014 14:33:49 GMT -6 rks said:

seanstr said "So, this is my question? Can a minor exhaust leak that is undetectable with the ear cause bad mileage?"

Answer: No

If you are only averaging 60 mpg, on many, many consecutive tank fills, and you are sure you are not loosing any to leaks or vandals....then you must be using it.
Do you know what your original variator weights were? I'm still confused by your statement about what you have now....13gr...14gr....rollers...sliders
Have you checked brake temps after driving scooter...is one dragging a bit...(don't get burned when doing this)
Have you done anything to the clutch? Cleaned out the belt dust...checked pads for glazing....maybe it's slipping some
Do you have a tach installed?.....It would tell you if the rpm's at your normal cruise speed have increased.

Still say pull the spark plug first...if it is covered with cartbon....it's getting too much fuel

Read this thread:

scooterdoc.proboards.com/thread/10488/long-ngk-c7hsa-last

Original steel rollers 13 g.

No tach

Can't check brake temp.

Soak plug wasn't dark

Belt area cleaned, was dusty.

I'll check new plug soon

Have not looked at clutch

[seanstr]

Aug 25, 2014 14:33:49 GMT -6 rks said:

seanstr said "So, this is my question? Can a minor exhaust leak that is undetectable with the ear cause bad mileage?"

Answer: No

If you are only averaging 60 mpg, on many, many consecutive tank fills, and you are sure you are not loosing any to leaks or vandals....then you must be using it.
Do you know what your original variator weights were? I'm still confused by your statement about what you have now....13gr...14gr....rollers...sliders
Have you checked brake temps after driving scooter...is one dragging a bit...(don't get burned when doing this)
Have you done anything to the clutch? Cleaned out the belt dust...checked pads for glazing....maybe it's slipping some
Do you have a tach installed?.....It would tell you if the rpm's at your normal cruise speed have increased.

Still say pull the spark plug first...if it is covered with cartbon....it's getting too much fuel

Read this thread:

scooterdoc.proboards.com/thread/10488/long-ngk-c7hsa-last

Picture of spark plug, it is blackened
I cleaned it

[gatekeeper]

Running a little rich. Check for fuel coming down the vacuum line. If not, make sure you have a clean air filter and fine tune the carb.

[seanstr]

So this means that my scooter is running too rich, but when I try to lean out the air fuel mixture it's does the opposite. I don't understand why.

[rks]

Where is your mixture screw....right side of carb, or left side? I just read an older thread about your strange mixture screw....the posted picture appears to be upside down to me....but anyway, the location of the screw, makes a difference in which way it is turned

Read this.......Lots of good stuff in the library section of this site.....all there for the taking

scooterdoc.proboards.com/thread/7863/bouncing-rpms-idle

[cyborg]

Vacuum fuel tap diaphragm leaking and being sucked into intake manifold ( just had that one myself couple months ago),, dirty air filter ? Can also cause a rich condition,,,all these things being discussed can also cause low mpg,,, having the throttle pinned all the time is a huge one also

[kz1000st]

Let me toss this in here. The outer part of the plug looks sooty. Sooty is a choke condition. Since they put a new carb on it's also possible that the electric choke is new. I would look into that. Maybe the choke isn't seating into the enrichener circuit and the extra fuel is coming through there. The inner part is a nice tan which would be fine back in the days of leaded fuel. Nowadays, in the age of EPA mods, a plug usually leans towards a cleaner, whiter look.

[seanstr]

Aug 26, 2014 19:35:11 GMT -6 cyborg said:

Vacuum fuel tap diaphragm leaking and being sucked into intake manifold ( just had that one myself couple months ago),, dirty air filter ? Can also cause a rich condition,,,all these things being discussed can also cause low mpg,,, having the throttle pinned all the time is a huge one also

Explain how you would know the diaphragm was leaking and being sucked up into the intake manifold

[cyborg]

Go to a cycle shop and get clear vac and fuel hose,,, I will never have black hose again on a bike,, just went thru this dance myself not two months ago on two bikes in a row within two weeks of each other,, insanity

[seanstr]

Aug 28, 2014 21:23:55 GMT -6 cyborg said:

Go to a cycle shop and get clear vac and fuel hose,,, I will never have black hose again on a bike,, just went thru this dance myself not two months ago on two bikes in a row within two weeks of each other,, insanity

So you were getting bad gas mileage, couldn't tell why. Got clear vac and fuel lines and saw what