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Discussion Starter · #1 ·
I have just installed the 35mm CR carburetors and airbox eliminator on my 07 Bonneville, and I was wondering what tuning I will need to do to the carbs. I have tuned old nitro R/C cars but never a motorcycle, so as much help as I can get the better :). I ride at 1100 foot elevation and have rejetted with respect to the air filters and the Triumph off-road pipes. Thanks so much in advance!

Jeff
 

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tuning

Hi Jeff,

Welcome to the forum and good luck with your Bonnie:)
I have the FCR's and tuning is similar .
The first thing to do is note where the carbs are currently set up, needle type and position, main jet size, low speed jet, and idle/air screw.

Keep a record of all of your testing and ride results.
Note low, med, and high rpm results of the butt dyno.

The higher gears will give you a better idea of the fuel mixutre, as the engine will stay in an rpm range longer.

Basically if the engine is popping or stuttering the rpm region is lean and it the engine is bogging, running rough, it's rich.

Of course you'll need to dyno to see how things really are with the engine. Another great tool is to install an Air/fuel mixture gauge in your exhaust system. Innovate makes several models. The A/F gauge registars real time A/F mixtures, so you can learn about what is really going on with the fuel delivery. I installed it last year and I have learned a great deal about tuning and my bikes performance.

It costs about $300 and takes 2 days or so to install, including having a sensor bung welded into the exhaust pipe. So it you like to tinker and learn, I highly recommend such a tool.

If you'd like to discuss further you can PM me and I have pics of my install.

Good luck

Hoopla
 

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Hi,

My bike is a '04 Thruxton, no airbox, K&N pods, D&D cans....the CR jetting recommended to me was:

115 main
60 pilots
Clip position #4 to start

I've yet to fit these on the bike, so that's all I can say at the moment.

Regards,

--Rich
 

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Discussion Starter · #4 ·
Thank you so much for the replies! I did what tuning I could, and ended up taking it to get dyno'd. They quoted me $250 for the complete dyno, which I thought was a fair price. I just got a call from the service advisor that they have not been able to get it running right and it will be $322 ($92/hr) + about $40 in new jets (I had already rejetted to what newbonneville.com sent me for the carbs based on my specs/elevation). And above that, they can't guarantee that they will finish in 3.5 hours and it might cost up to $460!!!

Does this sound right, or am I getting jerked around? It's an authorized Triumph service center at a BMW/Triumph/Ducati dealership...
 

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That's a lot of money.

Just do it yourself, then go do a quick pull to verify the settings.
yep thats way to much money.HECK YOU COULD OF GOT 39MM CARBS SET UP RIGHT CHEAPER.I would tell them ether get it right for $250. or give you your money back.
 

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Thank you so much for the replies! I did what tuning I could, and ended up taking it to get dyno'd. They quoted me $250 for the complete dyno, which I thought was a fair price. I just got a call from the service advisor that they have not been able to get it running right and it will be $322 ($92/hr) + about $40 in new jets (I had already rejetted to what newbonneville.com sent me for the carbs based on my specs/elevation). And above that, they can't guarantee that they will finish in 3.5 hours and it might cost up to $460!!!

Does this sound right, or am I getting jerked around? It's an authorized Triumph service center at a BMW/Triumph/Ducati dealership...
sounds like you're getting the high hard one. That's a rip off! Where are you?
 

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I do my own jetting then get a base line dyno run for less than $100.00 .I use that to see what needs to be changed,after i change it my guy will dyno it again for $35.00
 

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Mines about the same as Mike...maybe a tad cheaper. Really, you should not have to pay more than that. You need hour upon hour on the Dyno.
 

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Discussion Starter · #11 ·
I picked up the bike a little while ago, and it turns out they never even got it on the dyno. They didn't have the pilot jets in stock to rejet again, so the $250 they claimed to UNDERquote was a bunch of bs.

I took off the carbs again, and the jets newbonneville supplied are 150 main and 42 pilot (I have to send the pilot jets back because they are the wrong thread size and don't fit). The carbs were factory fitted with 115 main and 60 pilot. If I'm in Phoenix at just over 1100 feet, is 150/42 a good jetting combo? If not I can request different jets when I send back the pilots...

Thanks again for the participation, everyone. This helps A LOT.
 

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Discussion Starter · #12 ·
I need to order these jets asap, so any help with similar bike specs and elevation for jet setup would be great!

Just to reiterate, I'm at 1100 ft, 865 Bonneville w/ CRS carbs, airbox removal, and OEM off-road silencers... jetting reccommended was 150 main, 42 pilot (factory: 115 main, 60 pilot).
 

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I would guess the 150 mains are way to rich.my guess would be under 135 mains but not sure.jets dont cost that much maybe buy 120 ,125,130,135 and see where you need to go from there.Take the bike out run it wot in high gear for a few sec then let off to like 7/8 throttle if you feel it pick up at 7/8 throttle its to lean.If not try the next smaller jet till you find where it goes to lean then go back up 1 size and you will be close.
I hate to see guys sell carbs to people and not have a clue how they need to set them up.
 

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I need to order these jets asap, so any help with similar bike specs and elevation for jet setup would be great!

Just to reiterate, I'm at 1100 ft, 865 Bonneville w/ CRS carbs, airbox removal, and OEM off-road silencers... jetting reccommended was 150 main, 42 pilot (factory: 115 main, 60 pilot).
Dude,

The 150 main and 42 pilot recommendation is for a CVK carb! Put the 115 main, 60 pilot, and put the needle on the 4th position....then go get a EGA analysis from someone that doesn't lie to you! I can't believe they were trying to sell you a bill of goods w/o having even started working on your machine.

Anyway, I asked the same questions as you are 9 months ago on Delphi after I bought some used CR carbs off ebay...my bike is set up like yours and that's where the guys with similar setup were running sweet.

FWIW, a straight pull for me on the dyno is $25...$40 with EGA. I'm in Grand Rapids, Michigan and the shop is called 'Fast Bikes'.

Good luck,

--Rich
 

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If you bought a 35mm CR kit for the Bonnie chances are they were set up just right and only need to be synched ( at least that was my case ) . Mine came with needles set at 4 , 115mains , 58 pilots and were set for an 865 with a ARK running K&N ( British Customs ) .
Either buy a synch tool or take it to a shop. At most it'll be a hour labor . Any more they're ripping you off.
Install ( did myself ) was pretty straight forward . Any monkey with a starter tool box and half a brain can install them ( ex. Me) .
I for one plan on a Veypor system in the near future so I can tune them in a haste . After a year the thing will pay for itself .
 

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CR35's carbs

If you bought a 35mm CR kit for the Bonnie chances are they were set up just right and only need to be synched ( at least that was my case ) . Mine came with needles set at 4 , 115mains , 58 pilots and were set for an 865 with a ARK running K&N ( British Customs ) .
Either buy a synch tool or take it to a shop. At most it'll be a hour labor . Any more they're ripping you off.
Install ( did myself ) was pretty straight forward . Any monkey with a starter tool box and half a brain can install them ( ex. Me) .
I for one plan on a Veypor system in the near future so I can tune them in a haste . After a year the thing will pay for itself .
I bought mine from British Customs and it was a easy bolt on. The bike runs great. i am at sea level, Nark, K&N's, Oversize valves and Big Bore.
 
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