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Discussion Starter #1
I bought a 04 bonnie black about a month ago, i like the bike alot reminds me of my old ones from a few years ago but it has [email protected] pods and the air injection removed been rejetted etc. Anyway it gets terrible mileage around 40, im an older guy and just want to cruise around a few extra ponies means nothing to me so My question is this does anyone have the stock factory airbox and air injection stuff to sell? I would like to remove the pods and go back to stock! I know there are ways to increase the mileage as is, but i want the stock parts and jetting. THANKS IN ADVANCE for help locating the parts.
 

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your bike is not tuned right the air box dont hurt mpg if the carbs are jetted right the a/i wont help you ether .You will be ahead of the game getting the bike on a dyno and getting this set right.
 

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Discussion Starter #4
A friend has an 06 America and his bike got over 50 untill he did the switch and it dropped to the low 40s. He was not a happy camper so he put all the stock parts back on and it went back to the mid 50 again.

You are correct though, a dyno run would be a great help in getting it tuned right because right now it falls flat at around 5500 rpm thats my guess because there is no tach. there is no dyno within 100 miles of where i live... Jets have been changed and the needles shimmed.....tired of messing with it! Mikuni carbs are easier to tune!! Stock runs fine with me! Did everyone through there stock parts away or just want to hang on to them?
 

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drifter-

sounds like you should have checked the bike over a little better before you purchased it. mileage isnt really that much better with the stock configuration. what really affects your mpg is how you ride the bike. i have the airbox and AI removed with stock CVK carbs and ride my thruxton like it's stolen and still get about 43 mpg.

what also makes me think that your bike isn't tuned properly is you yourself mentioned you don't haul arse on the bike and seem to ride it conservatively. that said you should be getting better mileage, but even if you sort out the tuning don't expect to get mileage much over 45mpg. i find it hard to believe (but not totally unbelievable) that people are consistently getting over 50mpg. i am curious how these people are riding the bikes. i ride my bike to redline a lot of the time, and think these people are extremely conservative riders. the bike seems to love to live above 5,000rpm.

as far as the CVK carbs being harder to tune than mikuni's, i would disagree. the CVK's are one of the simplest carbs out there. way easier to tune than anything aftermarket for these bikes incliudng the mikuni, FCR and CR carbs. the CVK's do tend to fall out of tune a bit easier than other carbs though, but literally take 5 mins to synch and tune once your jetting is sorted out. unless you live in denver or somewhere at higher elevation getting your stock CVK carbs dialed in shouldn't be difficult at all, even if you only have some basic working knowledge of carbs.

as far as putting back in the AI, i dont really see any advantage to doing that whatsoever. it does absolutely nothing along the lines of improving mileage, but it will make your engine run a little smoother and cooler if it's removed.

try messing with the jetting and like others have mentioned a dyno run and gas analysis may benefit you. i'd rather spend the money in retuning the bike than pouring the cash back into making it stock, and for what it's worth removing the airbox has more of an effect than just " gaining a few more ponies." the difference is night and day from stock. i'm not saying the bike is a superfast after doing the mods, but throttle response is way better, the bike is more responsive and inspires confidence, especially if you have some sort of aftermarket exhaust. i have done the same mods you have plus predator exhaust and the difference is night and day. these bikes are slugs from the factory and seem to run way better when they are allowed to breathe. the only negative thing i can say about removing the airbox is the bike seems to run a little rougher on start-up when it's really coldoutside, but once it's warmed up it purrs.

when i was in denver i could never get the thruxton to run right; tried all differrent jetting schemes, one shim, two shims on the needle, etc, and never could get it dialed. recently moved to sea level and the bike runs like a dream with 42 pilots, 140 mains and no shims on the needle with 2.5 turns out on the air mixture screws.
 

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tip the bucket

They're right. The previous owner might have intended to make it a rocket by pouring petrol in; it's not too hard to see what jets you've got in it, See the Wise Mens tips.
Also,they rev a lot at high touring speeds, revs = thirst
 

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How is your bike geared? Most everybody who gets really good MPG is running a 19 Tooth front sprocket. As sbpark and Mike said you also need to get your bike tuned properly or gas mileage will suffer. There is no way I would ever go back to stock.
 

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Brm

Depends on where you ride. I need to 'tall' mine up cause it's so flat here. I could get heaps more out of a tank if I dropped the revs by gearing.
But sometimes I ride with mates in hills on sports bikes who have to shift down gears for power when it gets weird. I am glad i can nail the gap by rolling the throttle max instantly for overtaking; but I don't want a bike that will rev out to 'Bye licence' speed on the way to work.
And I know you can't get bloody 19 th fronts in Oz
 

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drifter-

sounds like you should have checked the bike over a little better before you purchased it. mileage isnt really that much better with the stock configuration. what really affects your mpg is how you ride the bike. i have the airbox and AI removed with stock CVK carbs and ride my thruxton like it's stolen and still get about 43 mpg.

what also makes me think that your bike isn't tuned properly is you yourself mentioned you don't haul arse on the bike and seem to ride it conservatively. that said you should be getting better mileage, but even if you sort out the tuning don't expect to get mileage much over 45mpg. i find it hard to believe (but not totally unbelievable) that people are consistently getting over 50mpg. i am curious how these people are riding the bikes. i ride my bike to redline a lot of the time, and think these people are extremely conservative riders. the bike seems to love to live above 5,000rpm.

as far as the CVK carbs being harder to tune than mikuni's, i would disagree. the CVK's are one of the simplest carbs out there. way easier to tune than anything aftermarket for these bikes incliudng the mikuni, FCR and CR carbs. the CVK's do tend to fall out of tune a bit easier than other carbs though, but literally take 5 mins to synch and tune once your jetting is sorted out. unless you live in denver or somewhere at higher elevation getting your stock CVK carbs dialed in shouldn't be difficult at all, even if you only have some basic working knowledge of carbs.

as far as putting back in the AI, i dont really see any advantage to doing that whatsoever. it does absolutely nothing along the lines of improving mileage, but it will make your engine run a little smoother and cooler if it's removed.

try messing with the jetting and like others have mentioned a dyno run and gas analysis may benefit you. i'd rather spend the money in retuning the bike than pouring the cash back into making it stock, and for what it's worth removing the airbox has more of an effect than just " gaining a few more ponies." the difference is night and day from stock. i'm not saying the bike is a superfast after doing the mods, but throttle response is way better, the bike is more responsive and inspires confidence, especially if you have some sort of aftermarket exhaust. i have done the same mods you have plus predator exhaust and the difference is night and day. these bikes are slugs from the factory and seem to run way better when they are allowed to breathe. the only negative thing i can say about removing the airbox is the bike seems to run a little rougher on start-up when it's really coldoutside, but once it's warmed up it purrs.

when i was in denver i could never get the thruxton to run right; tried all differrent jetting schemes, one shim, two shims on the needle, etc, and never could get it dialed. recently moved to sea level and the bike runs like a dream with 42 pilots, 140 mains and no shims on the needle with 2.5 turns out on the air mixture screws.
the cvk is no where near any easyer to tune as the 42mm mikuni carbs on these bikes.unscrew a plug change jets .set niddles by moveing a c-clip.Very easy to set up.fuel milage has more to do with getting mix right ar cruse speed,just off idle at steady speed.If you run the hell out of it you wont never get 50+ mpg .When my bike was stock i got over 50 on the highway and about the same with the big carbs on a stock motor.Iget mid 40s with the 989 motor on the open road and high 30s when i run the hell out of it.
 

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Airbox

Just had a long talk w/ a Bonnie friend on the same subject! I dont carwe that much about as few x-tra HP! The stock box keeps all real clean looking, & can be opened enuff to breath rite. Do your self a favor & dont put the a/i back on!!!! It really does no good & makes the pipes look crappy! I can see the airbox tho- my same feelings!
 

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Stock airbox

I bought a 04 bonnie black about a month ago, i like the bike alot reminds me of my old ones from a few years ago but it has [email protected] pods and the air injection removed been rejetted etc. Anyway it gets terrible mileage around 40, im an older guy and just want to cruise around a few extra ponies means nothing to me so My question is this does anyone have the stock factory airbox and air injection stuff to sell? I would like to remove the pods and go back to stock! I know there are ways to increase the mileage as is, but i want the stock parts and jetting. THANKS IN ADVANCE for help locating the parts.
I have a stock air box from an '08 Bonnie Black in great condition. The bike had less than 1k miles when it was removed. If you are set on taking it back to stock let me know.
 

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I also get in the low 40s (miles per gallon) since I changed to the configuration in my signature. I don't ride aggressively, but I keep it at 4000 rpm or higher, and have a 17-tooth drive sprocket.
 

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Mileage differences

I have an 06 Bonnie and have not taken the air box off yet. I have TORs and the carbs have been rejetted for them. I was getting 50+ mpg earlier this year. The station where I fill up had no ethanol at that point. Later this year they added ethanol to all of their grades of gas and my mileage dropped to the mid 40's. I don't consider myself an aggressive rider at all and don't think my riding habits have changed that much in the last few months. I will fire it up a little but do more putting around than anything. I am not sure if there are any performance differences with ethanol or not but I am pretty sure that the mileage drops with it as my car has lost a few mph as well.

Pops
 

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Discussion Starter #14
Well it sounds like i should forget the air injection..there seems to be different opinions about the airbox. When i bought the bike it had the pods so i was not surprised by it. Agreed basic tuning changing jets and shiming needles is easy stuff, done it many times in the past, looks like i will be doing it again......on this bike with or without the stock box.

Another friend has a 865 Bonnie with stock airbox and a complete Bub exhaust system, his bike runs great, no dog, no flat spots and sounds great gets mid to upper 40s in mileage so running the stock box with mods cant be all that bad. I have found with other modern Jap bikes that the stock airboxes are well engineered and work well, i have removed a couple to see the difference and the bikes ran worse. Granted there are mods to the stock boxes that help performance, rideability etc, my Drifter has such mods to the stock box it runs great and gets mid 50s in mileage.

Older bikes had poor flowing or very restrictive airboxes and removing them and adding pods always helped be it Triumphs, Nortons,Z-1s Zooks and others. This is my first experience with the new bonneville so my decisions are made from past experience and what i have read on here. It seems that modified stock boxes work fine and are cleaner, an added plus the oil blowby mist from the crankcase gets sent back into the engine adding additional lube to the top end of the engine. Im sure some will read this last statement and say rebuild the motor or some such.....all engines have some blowby new or used. A 360 crank engine has a hugh build up of pressure in the crankcase with every revolution of the crank.That pressure creates some mist i would prefer it to be in the airbox.

A 19T countershaft sprocket is on the way.....trying to find that 6th gear is going to end soon. I really like the bike and i have many mods coming down the road...Happy holidays everyone!
 

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Discussion Starter #15
Pops, i have found that to be true also. I have checked it with my bikes and trucks. You can almost bet whatever % of ethanol is in there you will lose the same amout of mileage. Another scam!
 

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drifter the air boxs on these box are very restrictive .Most jap bikes are 4 bangers they dont need as much air per piston as these bikes do because they use alot smaller pistons and have 4 carbs or throttle bodies feeding them.TRIUMPH didnt make these bikes to be sport bikes so they dont come stock with very good flowing air bixes or carbs or pipes for that mater.They had to close everything up to still use carbs and meet epa stanards .Efi jap bikes dont have to do that as much because they control fuel mix so well.The 4 valve head on these bikes flows alot more then the stock carbs that come on them.Being able to flow more air does not hurt mpg if anything it helps it .What does hurt it is not haveing carbs jetted right for the extra air you pick up thats a easy fix.Alot less work and money then putting the peace of crap air box back on.
Any of you guys that get bad mpg at steady cruse (highway speeds )need to look at pilot jets ,screw settings and niddle settings.Another thing that alot do is put way to big of main jets because it feels good ,about 50% of the time what feels good is not good on the track or the dyno.Reading plugs on these bikes is a joke to what most think looks right is way rich.Ethanol IN gas des not color plugs like the old gas did.You need to get a A/F reading on a dyno or a a/f meter or your just guessing on these bikes,I know I learned the hard way.
 

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Ethanol could be a complicating factor...

I am getting about 10% less mileage on all my vehicles using Ethanol blends (E10). That could make it tough to try to tune an engine to produce a prior fuel mileage that was achieved on pure gasoline.
 

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Depends on where you ride. I need to 'tall' mine up cause it's so flat here. I could get heaps more out of a tank if I dropped the revs by gearing.
But sometimes I ride with mates in hills on sports bikes who have to shift down gears for power when it gets weird. I am glad i can nail the gap by rolling the throttle max instantly for overtaking; but I don't want a bike that will rev out to 'Bye licence' speed on the way to work.
And I know you can't get bloody 19 th fronts in Oz
I beg to differ - newspeedmaster.com is where I got my 19T front sprocket from. Cost a small amount for shipping however.

And FWIW - it improved the fuel economy out of site.

On the highway I have got 4.5444015 litres per 100/km - Sorry you will have to do the conversion to MPG!

Stan
 

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Discussion Starter #19
Stang, you could have made it easier for us Yanks if you just told us how many bottles of beer 4.5 liters equal.....
 

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On the highway I have got 4.5444015 litres per 100/km - Sorry you will have to do the conversion to MPG! Stan
Stang, you could have made it easier for us Yanks if you just told us how many bottles of beer 4.5 liters equal.....
Although I believe it is illegal to speak "metric" in the USA, this IS an international forum, so here goes:

A "liter" is determined by how far a Scotsman in kilts can shimmy up a frozen pole on a hot day, divided by how many eastern Europeans can be sighted in an hour wearing black socks with sandals. This figure is then divided by the difference in goals scored by Australia over New Zealand in the Australia Cup, divided by 5252, or .642 Gallons.

A "kilometer" is measured by how many times the "Kilo" bird glances at his "meter" in an hour, multiplied by the height of the foam on a Guinness after 3.2 minutes. Take this figure, and divide it by the number of times a Morris Minor fails to start in February, or .6214 miles per kilometer.


Pretty basic stuff.

Anyway...

4.5444015 Liters = 1.2 Gallons

100 Kilometers = 62.14 Miles

62.14 miles / 1.2 Gallons = 51.78 MPG... pretty good fuel economy.
 
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