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 Little Advice... 
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Joined: Mon Dec 05, 2016 11:59 am
Posts: 219
Location: Panhandle of Florida
Post Little Advice...
I was farten around and started messing with both the Pilot Air Screw and the Idle Adjuster on my Mikuni Carb. During some preventive maintenance this weekend, when I took my plugs off they were very black (running very rich). How can I fix what I have screwed up with this carb I know nothing about. At idle after its warmed up, it runs at 900 rpms, when I engage the clutch to fwd it idles at 720rpms. This is a 4400 Black Death

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Mon Apr 16, 2018 4:07 am
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Joined: Sun Aug 09, 2009 12:50 pm
Posts: 574
Location: Muscatine, Iowa
Post Re: Little Advice...
On my motor I run the mixture screw 1 full turn out, and adjust the idle to hold 1170 rpm that gives me a 870-900 rpm in water Idle. I'm running a gutted stock or at times an Old BPS crossover pipe. That's on a MB 45.


Mon Apr 16, 2018 5:41 am
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Joined: Wed Jan 14, 2009 7:23 am
Posts: 6233
Location: Tarkington, TX
Post Re: Little Advice...
the 42 Mikuni the idle mix is an AIR screw. More you open the screw the more air you get (IE a leaner condition), The less you open it the less air you get (ie a richer condition).
Read the mikuni manual to learn the carb.

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Mon Apr 16, 2018 5:55 am
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Joined: Mon Dec 05, 2016 11:59 am
Posts: 219
Location: Panhandle of Florida
Post Re: Little Advice...
I read the manual,,, but still, doesn't help the fact I don't know what to listen for. After warming the motor up for 5-10 min. I have it idling at about 750 rpms. It responds well to the throttle and settles nicely back to the 750 rpm range. But with me not knowing what to listen for I have no idea if I have the carb set right or not. Would a short video of the motor running after it's warmed up and throttling it up a few times help if you guys could listen to it? To help me out?

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Lead, Follow or Get The Hell Out Of The Way!!!!
1754 Gator Trax Hybrid, Hunt Deck ,with MB 4400 Black Death HDR, Duck Slaying, Mud Slingin Machine!!!


Wed Apr 18, 2018 4:33 am
Profile YIM
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Joined: Mon Dec 05, 2016 11:59 am
Posts: 219
Location: Panhandle of Florida
Post Re: Little Advice...
guess I'm solo on this one...

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Lead, Follow or Get The Hell Out Of The Way!!!!
1754 Gator Trax Hybrid, Hunt Deck ,with MB 4400 Black Death HDR, Duck Slaying, Mud Slingin Machine!!!


Fri Apr 20, 2018 4:35 am
Profile YIM
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Joined: Sun Aug 09, 2009 12:50 pm
Posts: 574
Location: Muscatine, Iowa
Post Re: Little Advice...
Your Idle seems abit slow, is that in the water? Do you have a performance pipe on you motor? Some of the pipes scavenge the exhaust better than others. If you are running a stock muffler, I would open up your mixture screw to about two full turns out, to lean it out abit, and adjust idle out of water to 1100 rpm. With clutch ingaged out of water that should give you 850-900 rpm. In water it will be 750 rpm or so. When running my BPS Y cross over, I have to richen my mixture, because pipe scavenges exhaust better. And it helps with cold weather starting and Idle. Are you running stock plugs? I like the Autolite 3923 Platimum + plugs.


Fri Apr 20, 2018 5:34 am
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Joined: Mon Dec 05, 2016 11:59 am
Posts: 219
Location: Panhandle of Florida
Post Re: Little Advice...
running the Q muffler and Autolite PP-3923 Platinum.

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Lead, Follow or Get The Hell Out Of The Way!!!!
1754 Gator Trax Hybrid, Hunt Deck ,with MB 4400 Black Death HDR, Duck Slaying, Mud Slingin Machine!!!


Sun Apr 22, 2018 3:23 pm
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