17 miles per gallon...

[toogun]

Went through my first tank of gas of the season, mile mileage has gone from aprrox. 35 mpg to 17 mpg!!!
Quick rundown of what was done prior to getting back on the road.

1. Changed oil to 10w-40 Synthetic from Semi Synthetic.
2. Installed new plugs NGK DPR6EA9, same as what the old plugs were.
3. Modified my V&H Bagger baffles by extending the baffle and welding in 2 baffles halfway through the extension. and wrapping them with sheet metal instead of the glass packing.
4. Cleaned and oiled the K&N air filter with K&N cleaner and oil.
5. Marbelized the reed valve.

The baffle mod consisted of a 9" pipe welded onto the baffle giving an overall length of 19 1/2". I had originally cut 4 slots for baffle plates but only ended up using 2. Thinking that the OAL might be a problem (too much back pressure) tonight I cut off the extra 2 slots reducing the OAL to 16". I'll have to see how this affects the sound, performance etc.
The other thing is the amount of carbon on the end plate of the baffle was extreme especially for only 60 miles.
I'm also wondering about the sheet metal wrap, I wrapped the metal tight to the original baffle with no space in between. Should there be any air space? If so how much.
Pics attached;

Pic 1. Shows the carbon from the inside flange versus what it looked like before the above mentioned mods.

Pic 2. Shows the baffle plates in the extension.

Pic 3. Shows the sheet metal wrap on the original baffle.

Any comments, suggestions greatly appreciated.

[kawboysix]

Don't want to seem out of line so please don't take this the wrong way. Are you sure you calculated correctly? How do you figure fuel economy? A lot of people don't know how to do this properly. I don't think your bike would run with mpg that low. Seems to me it would flood and stall with that much fuel dumping. What method did you use to calculate mpg?

[cactusjack]

You're either running super-rich or are running WOT at 85 mph all day against a 35 mph headwind. Maybe your odometer is only turning half as fast as it was?

[Silent Sam]

..I'd be checkin for a fuel leak...is your overflow tube siphoning any out ?

If the bike is running like it always did...there is certainly a problem somewhere ! ?

Let us know what you find out.

[minst7877]

My bike drops mileage every year on the the first two to three tank fulls. First is always the worst and then progressively get better. Can't explain it but I think it is a combo of factors. First of all is the fact that the original tank of gas has been setting in the bike all winter and I believe it goes somewhat stale even though I put fuel conditioner in it. Second is the fact that it is cooler out and I have a tendency to leave the choke or enrichment knob pulled out farther and longer. The tank will also evaporate some fuel over the winter so you may not have all the fuel you think you do.

DC

[toogun]

Originally Posted by kawboysix

Don't want to seem out of line so please don't take this the wrong way. Are you sure you calculated correctly? How do you figure fuel economy? A lot of people don't know how to do this properly. I don't think your bike would run with mpg that low. Seems to me it would flood and stall with that much fuel dumping. What method did you use to calculate mpg?

We use the metric system here and I've been griping about it for 40 years because I was schooled in imperial measurements.
Anyway, $20.00 to fill @ $1.50 per liter... yes that's right..$1.50 per liter for premium. So that's 13.33 liters divided 3.785 = 3.52 US gal.
I drove 105 kms, 105 div. by 1.609 = 65.257 mi.
65.257 div. by 3.52 = 18.52 mpg. !!! Gee, better than I thought. lol

Okay I checked the trip meter and verified my gas receipt so I got 1.5 mpg better than I posted. Still sucks! I might have to work backwards undoing the mods too see what caused it to go in the dumper.

[cactusjack]

One of the problems with doing multiple mods without testing in between is you have no idea which one may be causing the issue now.

[toogun]

Originally Posted by minst7877

My bike drops mileage every year on the the first two to three tank fulls. First is always the worst and then progressively get better. Can't explain it but I think it is a combo of factors. First of all is the fact that the original tank of gas has been setting in the bike all winter and I believe it goes somewhat stale even though I put fuel conditioner in it. Second is the fact that it is cooler out and I have a tendency to leave the choke or enrichment knob pulled out farther and longer. The tank will also evaporate some fuel over the winter so you may not have all the fuel you think you do.

DC

I drained the tank last fall into a 5 gal gas can and added stabilizer. When I refilled the tank this spring it was back to the same level as I always fill it to, just under the fill rim.
I always push the choke all the way back in before I pull out of the driveway, warm up time 3-4 mins. max.

One thing that I forgot to mention in the list of things I did prior to getting back on the road was adding fuel system cleaner, injector cleaner to the gas as per the manufacturers recommendations.

[toogun]

Originally Posted by cactusjack

One of the problems with doing multiple mods without testing in between is you have no idea which one may be causing the issue now.

Ya your right, it's the shotgun effect. That's the downside of winter in Canada...and it was a long one too! Itching to get on the bike, wanting to play with my toys, can't ride it so might as well work on it.

[toogun]

Originally Posted by Silent Sam

..I'd be checkin for a fuel leak...is your overflow tube siphoning any out ?

If the bike is running like it always did...there is certainly a problem somewhere ! ?

Let us know what you find out.

No sign of any leak or gas smell when I pull into the garage, so if it's siphoning it out it has to be while I'm running and doesn't drip at all when parked. Is that possible...probable?
I did have the tank off over the winter I suppose I could have reconnected the lines up wrong, ya think?

[ringadingh]

Thats really bad mileage, I'm surprised too that it would even run. I usually put about 18 litres in during a fillup, and that gets me about 280km presently. When the weather warms up a little more I'll get up to 320km.
Is your throttle body clean, that will make a big difference in mileage, so will a vacuum leak.

[ringadingh]

I doubt your lines are connected wrong, its kind of hard to mix them up, and three of them are vents anyway.

[toogun]

Originally Posted by ringadingh

Thats really bad mileage, I'm surprised too that it would even run. I usually put about 18 litres in during a fillup, and that gets me about 280km presently. When the weather warms up a little more I'll get up to 320km.
Is your throttle body clean, that will make a big difference in mileage, so will a vacuum leak.

I usually get around 300 km to a tank 40%/60% city/highway. Throttle body is clean, not aware of a vacuum leak, also not sure how to check for one.

[toogun]

Hey ringadingh, I think I saw in an older post that you wrapped your baffles in sheet metal. How did you wrap them? Are they similar to the picture that I posted in this thread?

[ringadingh]

If you have a vacuum leak usually the idle will surge a bit rather than idle at a steady rpm.
I just fixed one on mine the other day and thas what it was doing, if its a bad vacuum leak the bike will not idle at all and die.
How many km are you getting to a tank now with the poor mileage?