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DYNOJET kit 3 months 2 weeks ago #31983

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I received another EBay set of carbs today and unlike the last set, these ones are in very good condition and everything came apart with no trouble what so ever.
First thing I noticed were the Main-jets.  Not "Mikuni".

 

 

Then found these:  A significant  "stepped" taper, 6 slots instead of the typical 5 and 2.5mm longer. 

 

 

Also:

 

 

The steel plate (Sits on top of the Diaphragm)  is OEM and 34 grams.   The other is plastic and is 3.4 grams.  A massive (relative) reduction in weight which I'll surmise is to make the entire assembly more response.  Note the stress cracking and warping ! 

 



I did a quick "search" on a hunch and believe these to be a DYNOJET kit.

 

The irony with all of this?  Someone was attempting to reap the advertised benefits of a "Dyno   Jet" kit .  "Stage 1",  "Stage 2"or "Stage 3",....unknown and when reassembling unwittingly missed the fact that 2 of the three "washer/spacers" that fit under the assembly on the center vacuum-tube, were missing !  That's the equivalent of 1 needle-slot.

Their results of this endeavour must have been very disappointing  and probably why these carbs have eventually made it to me. 
That's it ! 
 Just a  F.Y.I. .......for your amusement !
1980 KZ 1300 sr# KZT30A-009997
Always High - Know Fear !
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DYNOJET kit 3 months 2 weeks ago #31985

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It's destiny. You needed a winter project and the carbs needed professional attention. A marriage of man and machine. I can't think of a better person to figure this all out and who knows, maybe this happened to advance your way to 60 miles per gallon. You'll have to let us know when you hit 300 miles to the tankful.
That 6 slot needle is interesting. Runs leaner than stock  until 3/4's full throttle then rapidly reaches full flow in the last 1/4 lift. Most people think that more horse power happens when you install bigger jets when quite often, the mixture initially is more rich than it needs to be for safe cylinder piston temperatures.
Then there's the difference in weight of 30 grams between the discs. That would allow the throttle piston valve to rise higher and quicker at similar vacuum points.
I just know you're going to have fun "figuring" these carbs out.

Quite a few times when "track tuning" a bike, we ended up leaning out the jets by one or two sizes but the risk can be running too hot and burning a hole in the piston. And that's why I really enjoy fuel injection when an O2 sensor is monitoring the exhaust and reporting back to the ECU for fuel mapping correction. It's magic. You can map to run lean at low power output and richen up the map when running at high output levels to help cool the combustion chamber and pistons.

May your snow blower / snow plow remain idle and may your whiteboard marker not run out of ink. Cary on Scotch. looking forward to hearing about "Testing Days" results.

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DYNOJET kit 3 months 2 weeks ago #31987

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And the final(?) "coup de grâce" is:

 

This set had None.....not one....NADA.  

There's a tiny "tit" on the bottom of the needle holder, similar but smaller to the one that registers the holder correctly into the vacuum-piston.  This tilts the needle towards the air-filter side of the emulsion-tube opening. I'll speculate that this is intended to keep the needle centered when there's  LOTS of air-flow striking it.  Regardless:  Omit this spacer (needle is now significantly higher)  and that little 'tit" will now be riding on the c-clip......or not !    If it happens to align between the c-clip ends..........the needle will be that little bit lower.  
It would be interesting to see an instruction-sheet from the "kit".  I can't see this spacer being deliberately omitted and because 2 of the 3 the vacuum-tube spacers were missing I'll bet the missing needle spacers is an owner fuckup, as well !  
Trying to tune these carbs would have been unachievable and most certainly would have driven the owner/tuner insane.

So:  They'll go back to stock with missing pieces replaced and tuned accordingly.   
 
1980 KZ 1300 sr# KZT30A-009997
Always High - Know Fear !
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