Bad MPGs

KaptinAmerika

KaptinAmerika

Guru
:bang:

Hey everyone

I have an 06 K9, with a 117, PSI carb version 1, MLB Customs twisted pipes with outter ceramic coating.
I know there is a big battle over XXX and PSI and I don't have an answer for anyone as far as which is better. I can only tell you that initially I could not believe how much better my Dog ran when I insntalled the PSI and ran through the intitial, and quick, tuning. More power, crisper throttle blah blah blah.
However, jump forward a couple years and I am not so happy. No not neccesarily with the PSI because I cannot quite nail down what the cause is. I have experienced a substantial decrease in mileage while not having done anything different to my ride. I use to get 36 - 39 mpg now I am down to 25-28. My Dog still runs okay but it is acting like I changed his Dog Food or something. Backfiring on cold startup and the power curve that was there just isn't there anymore.
Any ideas or input would b greatly appreciated.

:flag:
 
narow37

narow37

Angry Southern White Man
check your plugs. might be fouled up. coil not giving good hot spark or plug wires need replaced. anyone else. How many miles on bike?
 
KaptinAmerika

KaptinAmerika

Guru
9,984
Changed plugs before I rode it this time so there fresh. Is there a better replacement wire than stock? Could there be an issue in the wiring harness, like under the tank, that could cause a reduced spark?
Thank You for you reply
 
BBChopper

BBChopper

Supports 2 Disabled Vets
Troop Supporter
narow37 said:
check your plugs. might be fouled up. coil not giving good hot spark or plug wires need replaced. anyone else. How many miles on bike?
Click to expand...
I would check that plus adjuct the carb, 10 % ethinol may be a factor...:spank:
 
V

Vegas

Well-Known Member
Maybe time to clean the carb internally and the throat. Also a good time for a compression check. Are you having any oil consumption or valve train noise that has gotten worse lately? Have you adjusted your carb since installing?
 
narow37

narow37

Angry Southern White Man
don't use anything less than the original size plug wires. the smaller diameter wires can cause interference with the ECH. as for wire harness not sure. also make sure your battery is in good condition and the voltage reg is good. can't really think of anything else except for making sure all connections are tight and there's no corrosion on any terminals and stuff like that. the only other thing I can think of is engine wear for some reason. lower compression, cam wear, and valve wear could all cause loss of power.
 
KaptinAmerika

KaptinAmerika

Guru
Sorry guys, I should have given you a little more. Carb is a PSI, shut up I don't want to hear about all the XXX this and PSI that. I like my carb, have had it for two years, and it had my bike running way better than it did stock. More in the seat of the pants, crisper throttle, smoother power curve blah blah blah. The carb was the first thing I went to over this and Bruce at PSI wasted no time taking the carb back, rebuilding it, updating it to the newest innternal mods through version 4, and getting it back to me and at no charge, other than shipping, I might add.
Anyway, I hope everyone knows I was just kidding when I said 'shut up' I appreciate everyones input here, the compression is right at 108psi in both cylinders. Is that good? I have a 117 S&S book but I could not find compression numbers in it. No oil consumption and my valve train has always been a little noisy, I think thanks to the TP rocker boxes but that was another issue that BD never resolved and they just looked the other way. Since it is a PSI carb I did do all the pre ride adjustments. I can tell you that before Bruce rebuilt the carb I could not get any type of tweaking on it to change anything. But since the rebuild it is back to its old self again. With all the adjustments on the out side it is kinda cool to make a tweak here and a tweak there, as you ride, and feel the difference right away.
 
KaptinAmerika

KaptinAmerika

Guru
The battery is fine. I replaced my stock battery. I was having all kinds of electrical problems, especially the speedo. The Big Dig tech rep happened to be at my local dealer when my bike was there and he told the servie manager to replace the battery with a Harley brand that has 440 cranking amps. This animal of a battery is a full 1" thicker than the stock battery but it rid my Dog of all the electrical fleas she had. I keep it on a tender now so it always at peak operation.
 
lee

lee

Well-Known Member
first I would check you don't have an intake / exhaust leak. Also clean your air filter if you haven't done so in a while. I think your compression may be on the low side as the S&S website mentions the need for releases at 180+ psi, but interesting both cylinders read the same. You could drop some engine oil into the sparg plug holes and crang it again - if comp noticebly higher you have worn pistons / rings / cylinders. Also get a leakdown test done. How many miles on the bike?
 
KaptinAmerika

KaptinAmerika

Guru
Sorry folks, had to go trim the trees in the front yard. I am definitely going to pursue the compression issue if the comp releases have to support 180+. Wish me luck cause this Dog is way to young to already have worn rings and that. I will drop some oil in the cylinders though and see what happens.
Thanks for everyones input.
 
B

busa2r

Member
Make sure you disconnect comp releases before doing a comp test. What was the part# on the 440 cranking amp battery i would like to see if it fits in a 06 pitbull Thanks
 
bdmridgeback

bdmridgeback

Low Down Chop Shop
Maybe some prick walked out of a bar and did some unknown carb adjustment for you to make your bike "run better"!!!
 
1mndg

1mndg

RIDE IT HARD!!!
I would lean more towards the fuel. I would try a different fuel or some octane boost to see if that changes your MPGs. It did for me. Fuels vary at different times of the year. My MPGs go up and down depending on what fuel I run. Mostly SUNOCO, but can't always find a SUNOCO station.
 
dogvet

dogvet

Banned
[QUOTEthe compression is right at 108psi in both cylinders. Is that good? QUOTE]

Your compression is reading 108 psi because the compression releases are opening. cranking compression should be over 125 psi. There is a connector under the tanks that will disable the releases. 108 is going to be normal with the releases open.

Is it backfiring through the carb or out the pipes when you start it?
 
Cutter

Cutter

Well-Known Member
KaptinAmerika said:
...No oil consumption and my valve train has always been a little noisy, I think thanks to the TP rocker boxes but that was another issue that BD never resolved and they just looked the other way...
Click to expand...
BDM was replacing the valves, rockers and/or covers with the S&S under warranty... I didn't notice the drive train noises changing in mine until I compared them to others...

I have seen some extremely sloppy valve guides - worse than mine - but mine were definately out of spec @ around 12,000 miles, and I dont really beat my Dog.
 
MARV

MARV

Well-Known Member
i've been getting about 140 on a full tank with the PSI and plugs look good.

last week in 30 degree weather I ran out at 108! coasted into a gas station.

bet its a float bowl issue causing a rich condition.
 
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