hand adjustable fuel mixture screws for TRX ???

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pininfarelo
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Re: hand adjustable fuel mixture screws for TRX ???

Post by pininfarelo » Fri Dec 03, 2010 8:43 am

Quan-Time wrote:wouldnt be too hard to make a set honestly. I got a spare set of mikunis here i can inspect / measure if theres enough need.
I would be interested in purchasing a set if you get them. :)

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Homer
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Homer » Fri Oct 28, 2011 6:29 am

While I've been sitting around twiddling my thumbs, waiting for my tubes and needles to arrive from the US, I decided to have a look at re-setting the mixture screws on the carbys, only to find you can barely access the screws because of their position..
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A search for easily adjustable mixture screws led me to this thread, amongst others, and it quickly became apparent that you simply can't buy them, so I thought I'd have a lash at making them myself.

Luckily I has a couple of stainless knurled knobs that my dad made me at work, when I was about 15. I'm now 51, and no I never throw anything away!

I started out by carefully grinding the slotted end of the mixture screw down until the screw slot was gone.
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Homer
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Homer » Fri Oct 28, 2011 6:33 am

Next I centrepunched the newly ground end. Its important to get the mark as close to the centre as possible.
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Then I drilled about 4-5mm deep hole with a 3mm drill bit, You can see its not perfectly in the middle, but its close enough not to be a problem.
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Next I got a 3/16 inch by 2 inch brass countersunk bolt.
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Homer
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Homer » Fri Oct 28, 2011 6:41 am

Then I ground the last 5mm of the bolt down until it fits into the hole drilled into the mixture screw.
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Then drill a 5mm hole in the stainless nut, and put a nut and some loctite on it to keep it from turning on the bolt.
Soft solder the mixture screw and 3/16" bolt together. Its important to get the bolt and screw as straight as possible while the solder is still soft. It took me three or four goes to get it straight.
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Homer
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Homer » Fri Oct 28, 2011 6:43 am

As you can see, once their back on the carby, they're easily accessible for adjusting.
033.JPG
Job done, its beer o'clock!
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schmiffee
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Re: hand adjustable fuel mixture screws for TRX ???

Post by schmiffee » Fri Oct 28, 2011 8:32 am

If this works as you say and as easy as you imply...you're a freak!! :D
Understeer - when you hit the fence with the front of the bike.
Oversteer - when you hit the fence with the rear of the bike.
Horsepower - how fast you hit the fence.
Torque - how far you take the fence with you.

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Mincehead
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Mincehead » Fri Oct 28, 2011 7:33 pm

Nice little mod Homer. =D>
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Con Rod
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Con Rod » Tue Apr 10, 2012 2:24 am

Very handy mod indeed.

Did anybody ever come accross anywhere you can buy an easily adjustable fuel screw for the standard TRX carbs?

I have seen a few for the Keihin FCRs but not for the standard Mikunis
Paul

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Homer
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Homer » Tue Apr 10, 2012 12:43 pm

Don't think you can mate, thats why I made the ones I did.

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Con Rod
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Con Rod » Tue Apr 10, 2012 1:45 pm

yup, I may have to go that route but was hoping for the lazy option :D
Paul

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Dav
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Dav » Wed Apr 11, 2012 12:40 am

Ages ago when I had my DR motard I bought an extended screw for the Mikuni carb from keintech:
http://www.kientech.com/ExtendedFuelScrews.htm
They might be able to help or know somewhere that can 8)

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Con Rod
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Con Rod » Tue Apr 17, 2012 1:39 pm

Decided to follow Homer's example and make my own fuel screw adjusters

started with some brass all thread
1 a.JPG
Which I then filed down to size and put a notch on the end. Also flatted out the other end so I could turn them
1.JPG
Then I soldered that to the back of the fuel screw (was not finished at the point I took the photo but you get the idea)
1c.JPG
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Last edited by Con Rod on Tue Apr 17, 2012 1:43 pm, edited 1 time in total.
Paul

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Con Rod
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Con Rod » Tue Apr 17, 2012 1:41 pm

then screwed them back into the carbs and bobs your uncle
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3a.JPG
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Paul

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Rod.s
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Rod.s » Wed Apr 18, 2012 12:27 pm

Con Rod wrote:then screwed them back into the carbs and bobs your uncle
4.JPG
3a.JPG
6.JPG
So the carb kits turned up ok :D :D Well done looks just like a bought one =D>
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Con Rod
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Re: hand adjustable fuel mixture screws for TRX ???

Post by Con Rod » Wed Apr 18, 2012 1:04 pm

yepo, turned up, all looks good, very happy with them. Fuel screws fit!. Will refresh the rest of the carbs at the weekend maybe
Paul

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