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VT1100 tuning help

  • WW

    I have an '02 spirit 1100 that I installed a set of drag pipes and a dynojet tuning kit a few years ago, has been lean at idle ever since, but ran pretty good otherwise, aside from popping through the exhaust on decel. Found TJ Brutal Customs this year, bought a set of stacks and a tuning kit. I installed the 50/200 jet combo and put 2 shims on the needles with the clip in the 2nd notch from the end, and the bike wouldnt start at all. Rigged up a fuel source so I could run it with the tank removed, and the bike would only start if I sprayed carburetor cleaner in the left carb. Pulled them back off and found that the 50 pilot jets dont seem to be as large internally as the 48s, so I swapped in the 48s. Now it starts and runs great at idle, mixture screws at 2 1/2, and revs fine in the shop. Put it all together and went for a ride, and when just cruising around 50mph it acts like it is running out of gas, sputtering and popping through the exhaust. If I downshift, it clears up at the higher RPMs. The problem is happening around or just under 1/4 throttle. What I'm trying to figure out is if I need the bigger pilot jet or if I need to raise the needle more. I also just replaced the spark plugs at the beginning of trying to get going again.

  • TJ

    @Will Weber youre on the right track, - this might help in understanding how to tune - t.ly/GDPnz

    DO FUN SHIT!
    Check the FAQ's here for tons of tuning info and more!! - t.ly/MA6r6

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  • WW

    I've had these carbs in and out probably 20 times to make adjustments and still cant get it to run right. Makes me wonder if i may have an ignition problem. Does the vt1100 use the same resistor caps as the 600/700/750? The tune up kit on TJBC says it fits all of the smaller displacement bikes but doesn't include any of the 1100 displacement options in the fitment list... Is there a different cap for the 1100 or do they not use them? looks like the plugs are the same.

  • TJ

    @Will Weber

    The VT1100 calls for a DPR7EA( plug which is one step hotter than the plugs fopr a VT750 and 600. and yes they use the same resistor caps as the other shadows. 

    you may have a vacuum leak or a compression issue, you may want to do a compression test and a leakdown test too

    DO FUN SHIT!
    Check the FAQ's here for tons of tuning info and more!! - t.ly/MA6r6

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  • WW

    It starts and runs good for 10 minutes or so, then starts to misfire or load up. If I let it cool down again it does the same thing. I have new diapragms and carb boots, and have sprayed around the carbs with carburetor cleaner and don't notice a change in engine speed. It only really acts up when riding and under load. I'll double check that the plug number is correct. Do you sell the wire and resistor caps without the plugs? The wires are probably original, since I haven't ever changed tham and Ive had this bike since 2008.

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  • TJ

    @Will Weber you can use the DPR8EA9 and you wont have any issues. Just make sure theyre gapped properly. 
    How do you know its misfiring? what color are the plugs? What do you mean by "loading up"? is there a power loss? or is it a sound? is the bike stumbling? is the fuel pump still intact? 

    DO FUN SHIT!
    Check the FAQ's here for tons of tuning info and more!! - t.ly/MA6r6

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  • WW

    I just rechecked, and I used the DPR7EA-9 when I replaced the plugs this summer. After riding for 10 minutes or so, the engine starts to lose power, pop through the exhaust while on the throttle, and it is jerking like when a car has a misfire. If I clutch and rev the engine a couple times it clears up for a short amount of time. I pulled the plugs out the last time I was messing with it and they were black, I cleaned them and rechecked the gap at that time as well as leaning out the mid range by moving the needle clip up by a notch. The problem is happening a  round 1/4 throttle. I currently have the smaller pilot jet and I think the middle main jet installed. But I think I'm lean at idle because it won't start without the choke applied even when it was in the 90s. 

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  • WW

    The fuel pump is installed and working. 

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  • TJ

    @Will Weber If you have a clip needle get rid of that.  That tells me someone else has tried to mess with your bike before you. Unless you were the one who installed it. I have NEVER had any luck in 20 years tuning a bike with those things, they run WAY too rich and the taper is not gradual enough. I would get the stock needles and go from there. 

    DO FUN SHIT!
    Check the FAQ's here for tons of tuning info and more!! - t.ly/MA6r6

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