# 05 brute 750 low speed miss fire



## 315scott (Oct 19, 2013)

I have a 05 brute 750 with 1250 miles,muzzy pipe,dual 2''into single 3''snorkel,dyna ignition box,180/180 kehin jets,DJ needle 4th notch,mixture screws at 2 1/2 turns.i installed all these parts last fall and it runs extremely well wide open and fast crusing speeds.at part throttle 1/4 or less it misses terrible.
put new boots on carbs no better,tryed the mixture screws in to 1 1/2 in 1/4 turn increments,no better.new plugs no better,rear plug was black front plug tan.took the lid off the air box no better.move the clip on the needles up one then down one worse lost power on hard acceleration .
today I put the stock ignition box back on and the misfire is gone at part throttle,but lost a bunch of power on hard acceleration.is my dyna box junk?would my stock box with an advanced timing keyway be a better setup?


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## SLVRBRT (Jun 27, 2012)

Step up a size on pilots maybe?

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## 315scott (Oct 19, 2013)

I kind of leaning away from carburation,miss is gone with stock ignition box.but the lack of advance murders power output.


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## SLVRBRT (Jun 27, 2012)

Yeah I wouldn't want to ride mine without the Dyna cdi. Just feels weak.

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## dman66 (Feb 20, 2011)

I hope u installed at least #4o pilots. Did u tune it with a wideband.


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## 315scott (Oct 19, 2013)

forgot to mention 40 pilot jets,tuned by the tryed and true seat of the pants and plug reading.


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## D-LUX (Apr 14, 2013)

The part throttle miss is from the dynatek. They all do it even if tuned properly 


/i\


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## dman66 (Feb 20, 2011)

I did a little tuning yesterday with a wideband , and I installed #42 pilots - A/F screw front 2 1/4 out - rear 3 out. .030 shims on each factory needle and 162 front / 165 rear main jets. All jets are Keihin. I still need to tune mid and WOT ranges but Idle - 1/4 throttle is roughly 12.5 - 13 on the wideband. I have a single 3" intake with a little air restriction and a Muzzys Pro.


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## SLVRBRT (Jun 27, 2012)

D-LUX said:


> The part throttle miss is from the dynatek. They all do it even if tuned properly
> 
> 
> /i\


Had Dyna CDI on my old 650 and on the 750 for years. Never had a miss or stumble of any kind. Aside from when carbs were gummed or dirty, etc.

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## D-LUX (Apr 14, 2013)

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## NMKawierider (Apr 11, 2009)

SLVRBRT said:


> Had Dyna CDI on my old 650 and on the 750 for years. Never had a miss or stumble of any kind. Aside from when carbs were gummed or dirty, etc.
> 
> Sent from my SGH-I747M using Tapatalk


 Me too. Mine has never missed a lick. It start out lean at 1/8 throttle like most but the #40 pilots and shims too care of that.


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## 315scott (Oct 19, 2013)

ok guys I have learned a couple things,installed msd plug wire ends and misfire is completely gone.reinstalled the dynateck box.got the float level specs and my floats were around .050 high rear one slightly higher.now with the float correctly adjusted the pilot is lean,i am out 3 turns front and rear and there is a small I mean very slight stumble at tip in at walking speed,dont notice when riding very much just when barely rolling.plugs look nice and tan.going to try some 42 pilots.
machine runs stronger than ever.drag race style start it carries the front about 35' with me leaning forward,sitting straight up it will go right on the rear rack.from a 20-25 mph roll it stands up nicely.
I have a vforce john clutch spring setup in it.
I bought this for my wife to ride now I think it is a little too much for her,LOL.


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