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J

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Discussion Starter #1
i recently built a 2004 bonnie custom. we eliminated the emissions and put new jets in the carbs. well when i finally hooked the carbs back up they were continuously flooding over and spilling out gas. i was wondering if there is anyone who might be an expert on the carbs that might be able to point me in the right direction. if you can please email me at [email protected] any professional advice would be greatly appreciated. if you are interested in seeing the new bonnie chop log on to choppahead.com its under the head line "check out the new bonnie chop"
 

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Stuck float needle in one of the carbs ? Tap the side of the float bowl with a screwdriver handle and see if the gas stops. If so, run some fuel conditioner thru to lube it or drop the bowls and needles and clean them.
 

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Plugged vent line to the carbs will cause them to flood...more common on Calif emissions removal because this line runs to a canister on Calif models, and some have plugged it when removing the canister...this would still be my guess on the problem you have described just after "emissions removal".

Larry
 
J

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i guess i should have given a little more info.... i have done everything i can about the floats i even put new needles in thinking maybe the new gas was slipping through the old ones becuase they sat dry for a few months.. so ive tried everythng with the floats...... larry you mentioned the vents bein plugged is there any mor einfo you might be able to give me on the vents....... i will pm you.
 
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i guess i cant pm you until i made 10 posts....... couold you please email me i woiuld appreciate any more advice you could give
 
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larry thanx it worked but i still have a pause on my throttle response any suggestions?
 

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Jinks bolts has a detailed (down loadable) step by step carb diagnostic,jetting booklet on these carbs.

Steve, Gears ed al. :cool: :-D :cool:
 

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Jay,

Sorry, I've been off-line for a few days for the holiday. Glad you got the flooding resolved. Need more description of the "throttle response problem"...what rpm range or speed & gear? What is your modification level (i.e., what mods have you done besides the emissions removal). Is the airbox in place...what mufflers are you using?

The pilot screws are normally set for a prettly lean mixture, and can cause some throttle response problems at rpm's below 3K. The pilot (mixture) screws are covered with an anti-tamper plug on '03's and many '04's. The plug is about half the size of a dime and has a tiny hole in the center...it is aluminum in color...and it is located at the front/center on the bottom of the carb...look for it with a mirror. If yours is a later model, the pilot screws are not covered, but have "D" shaped screw head centers; i.e., they take a tool shaped in the shape of a "D" to turn them...you can make your own out of very small copper tubing or some steel and a little file work :-D . Screw the screws in all the way till they stop...easy does it, don't ruin the seat...then back them out about 3 turns and try it to see if your problem is better. The pilot jets are 40 stock. If you go much more than 4.5 turns out, you will need to get the next size larger pilot jets (size 42). Larger than size 42 main jets are seldom needed unless you have header pipes installed that have no crossover pipe (with no crossover, you may need to run 45 pilot jets--I did with just more open silencers and snorkel removal.

You can remove the plug covering the pilot screws by using a small drill bit to drill the tiny hole larger by hand...then screw a grabber type screw into the plug and use pliers to pull the plug out.

Depending on what your "custom" is, you may want to look at a Triumph manual to get the final gear ratio specs and change your gearing to be very close to the stock specs.

If you experience "flat spots" in acceleration in the mid-range (approx 4K--6K rpm), you may need to put one or two 0.5 mm shims (0.020") on the carb needles. This will richen the mid-range mixture some. Many have found that using Thruxton needles in the '03 & '04 carbs help a lot in the mid-range. The Thruxton needles are more tapered--hence, richer in the mid-range.

One thing to keep in mind about these engines...they love rpm and don't take kindly to lugging at low rpm. I won't run mine less than 3000 rpm in 5th gear. They really shift smoothly at 5000 rpm's. I have rode all day between 5000 and 5500 rpm and gotten 50 mpg.

Larry
 
J

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Discussion Starter #10
larry that is a great help. the kit had 155 main jet but i don't remeber what the pilot jet was. but we totally removed the airbox and now just has foam filters and we are running an open exaust. the hesitation is at the begining of acceleration. i do believe it is running a little rich. the air mixture screws are blanked out. but you have given me great information i super appreciate it. if there is anyhting i can ever do for you email me ....... thank you
 

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when I've messed with my idle mixture I can always tell it's too rich when it hesitates off idle.

I have 42 pilots and my idle screws are set to about 1.25 turns out. The 155s may be a bit big, but that's what I have in my bike. I don't remember many needing mains that big besides me, but mine runs well and I have open pipes and no airbox.

Be sure to post some pics! Is your website down?
 

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Jay,

I would really recommend you get her on the dyno with EGA when you have it pretty close to what you think is good jetting and mixture. I have removed the airbox and run NH Toga mufflers on my 790cc. I run 158 main jets, 42 pilot jets (the stock 40 pilot jets would work also), and the stock needles. Most indicate the stock needles are too lean--in my bike the stock needles are a little rich, but not enough to correct by machining the carb slides. For me, getting the main jets close was prettly easy--though time consuming. The needles were another story...without the dyno run, I was just guessing since I was dealing with rich and much richer options. The pilot circuitry can be run from "spot on" to pretty rich without affecting performance much, IMHO.

Larry
 
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the web site was down for a couple days do to server problems. its back up now choppahead.com...... its in the news heading... new triumph
 

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Sweatmachine. Was it you asking me about my friends XS650 hardtail? Did you find it?


www.wb5evo.com
www.650motorcycles.com #1011


It is also going to be in a calender for some company. He will be October 2007. Maybe 2008 at this late date. I will try to find out what company & year.
 
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im not sure how to post pics on this site im not a comuter guy. but the bike weighs some where around 400lbs the old ones we build weigh about 300. we build hardtail frames for anyone interested in customizing their new twins... give me a shout if your interested
 
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