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Stripped Hex Head - How do I get it out?

Typically the smaller stuff gets plugged up first. Carb cleaner will swell rubber, so remove the slide before spraying. Remove pilot and main jets, and the pilot fuel screw. Make sure you get the washer and o-ring out of the fuel screw cavity. Focus your attention on the fuel screw circuit and transition ports (the small holes at the base of the throat, just in front of the slide).
Thanks for that.

Yeah a good carb cleaning and a new spark plug to get started. You'll know those are a fresh starting point. Grab a multimeter and check resistance on the ignition coil. It's an easy check, just find out the specs from a manual. Those three things done will narrow down possible reasons for the bike acting up. And they'll be on your maintenance schedule now. If there's still trouble you can dig in.
Right, picked that up from your thread - to check the ignition coil.

Need to get a spark plug wrench! I left a nice T-handle one back on the DR650 in India.

Question for when I put it back together - what's the correct way to set the baseline for the idle speed screw (throttle stop in my case)? Is there a recommended number of turns out from fully wound in? And then run and set it by RPM feel/sound? (no tach)

I guess I should start another thread for this carb rebuild :mrgreen:
 
Yeah, strange that they're part of almost every drill bit set. I'm rebuilding my tool collection and was looking for a set that would come with flat and philips bits and hex bits but oh no, hex bits come separately but instead you get flat, philips and square bits.


Hah, yeah, lots of ways to do this. Had so many square bits, was ready to sacrifice one but it didn't damage it.

This carb... so this DRZ has been sitting for the past 2 years as the previous owner didn't get time to ride her and she's not running smoothly. I guess the ethanol in the fuel has gummed up all the little circuits in the carb. It fires up and idles, sort of OK, but it sputtered, coughed and died beyond half throttle, in traffic on a test ride. So that's telling me the pilot circuit might be fine, but still going to clean it up and going to pay close attention to the main jet circuit, maybe the needle jet is gummed up.

If it ran good when put away, Carb needs to be cleaned.
If it ran this way when put away, the main jet is likely sitting in the bowl :giveup:

The O ring will be in the mail tomorrow, replace that as well.

The single best cleaner other then my Sonic tank and soap made for carbs..is of all things,,,,, a Motorcraft product
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Do not soak plastic or rubber bits in this, but jets, carb body and other metal with varnish on them... it does great.

You dont have to dunk the carb in two cans worth... you can set the carb in a pan and pour the cleaner in the passages your having issues with. then put the small parts in the pan covered in run off as you "fill" the carb.

Give a shout if you have any questions..... I've worked on a few DRZ's
 

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If it ran good when put away, Carb needs to be cleaned.
If it ran this way when put away, the main jet is likely sitting in the bowl :giveup:

The O ring will be in the mail tomorrow, replace that as well.

The single best cleaner other then my Sonic tank and soap made for carbs..is of all things,,,,, a Motorcraft product

Do not soak plastic or rubber bits in this, but jets, carb body and other metal with varnish on them... it does great.

You dont have to dunk the carb in two cans worth... you can set the carb in a pan and pour the cleaner in the passages your having issues with. then put the small parts in the pan covered in run off as you "fill" the carb.

Give a shout if you have any questions..... I've worked on a few DRZ's
Sweet, thanks for that, Eric.

You were right on the money. The pilot screw o-ring is shot:

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Washer removal tool ;)

And yeah, lots of gunk and varnish all over.

i-dzJt9tJ-M.jpg

Don't have a garage so doing this in my kitchen! (It's too cold out on the porch)
 
Does the needle valve need to be replaced? Looks like it's got a groove. An uneven one at that :ponder:
i-ZjMvxfc.jpg


Valve seat has some junk:
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I can't read the numbers on the main jet or the starter jet. The pilot jet is a 22.5. I'll just put it all back in after a deep cleaning. Oh yeah and lots of abused screw heads.
 
Good progress. Probably wouldn't hurt to replace that needle valve.

Nothing wrong with a "kitchen garage". It's a perk of being an adult, you can run your house like you want. Mom always said "when you have your own house then you can do what you want". Done! I have electrical work setup on the kitchen table now. And I have a garage to work in, it's just too cold!

Also I sometimes eat dessert for supper.
 

So we are not talking apples to pomegranates
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The O ring you found damaged is the fuel mixture screw O ring.

The O ring Im sending you that i suggested you replace as long as your in there is the float needle seat O ring.

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You remove the screw seen holding the seat in place and gently pull up and twist the seat up and out.
The old O ring likely looks something like this
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For most Mikuni carbs, that little O-ring is the same, right?
 
The O ring you found damaged is the fuel mixture screw O ring.

The O ring Im sending you that i suggested you replace as long as your in there is the float needle seat O ring.
Ah, you're right. Got it now.

Do you know the dimensions on the fuel mixture screw O ring (92055A)? I have a big box of assorted o-rings. Want to check if one of those fits.
 
Ah, you're right. Got it now.



Do you know the dimensions on the fuel mixture screw O ring (92055A)? I have a big box of assorted o-rings. Want to check if one of those fits.

1.13x2.7mm is the actual size however

1.5x3mm Will work
 
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1.13x2.7mm is the actual size however

1.5x3mm Will work
Thanks. I have 1 x 3. Looks like it fits.

Question on jetting, this bike has the full MRD exhaust, 3x3 mod, big bore kit and so I presumed the carb was re-jetted but just confirmed that the jets are stock (main 142.5, pilot 22.5, starter 62.5). Does that seem right? Don't all these mods need a main of 155 or 160? Does the pilot need to be larger?

If these are not the right jets, should I get a jetting kit and go from there?
 
Stock needle is going to be lean at low throttle opening no matter how you jet it
I would get a James Dean jet kit and start with the blue needle clip 4, 150 main stock pilot jet and about 1.75 turns out
 
I got the bike running! :rider:

Thanks to Eric for the hard-to-find float valve seat o-ring. :chug:

Put in a new JD Jet kit, new gaskets and o-rings all around, lubed up the sticky throttle cables and BARRRP!

[ame="https://www.youtube.com/watch?v=t7hB6EpncHo"]DRZ400 First Fire Up After Carb Rebuild - YouTube[/ame]
 
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