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got a 2000 mach z stock motor except for a exhaust can last year fouled plugs went to a 45 piolit solved the problem now after getting it out this year fired right up no problem took carbs off cleaned them like i do every year put boyesen rad valves in it and put carbs back on all new gas and everything and now it smokes like a ##### and fouls plugs bad and now what it does which it never did before is with the choke on full and engine cold it takes 10 or so pulls to start it then when it does start it smokes real bad and runs real rich bad set of rad valves?i checked all this again chokes they :cussing: :cussing: :cussing: :cussing: are not sticking ,needle and seats are all sealing,floats were adjusted last year and not touched this year,oil pump not sticking in fact its a little on the lean side just a fuzz so any suggestions???? i only changed the reeds will it cause it to run that rich??? and why so hard to start???and the smoke is not antifreeze it is fuel rich the plugs after 5 minutes all of them now are black it revs up good and all but man it never ran like this until i put the reeds in is it just a whim that something else happened when i put the reeds in and its not the reeds at all?????
 

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I'll take a crack at this one.

First off, your engine seems to show "typical" Boyesen reed/Rad installation.

First - hard starting

Boyesen makes your engine run LEAN on the bottom. typically to the tune of 1 to 1-1/2 turns on the fuel mixture on the pilot stage.

A motor is usually much harder to start if it's lean.

Second - rich running

Boyesen usually richens out the mid-range and mains- typical is about 2-3 main jet sizes.

These problems you are talking about seem like normal symptoms of Boyesen installation.

I use boyesen, have been ever since I have had a motocross. All my reed sleds have had them. Very good product, just needs a little tuning.
 

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after doing what madsledhead said to do, if it still does what it's doing now check to make sure the reeds are seated properly against the cages. If there is any light what so ever showing between the reed tips and the cages then that is probably your problem, i had this happen to me and it was letting way to much gas in the cylinders. I had the same symptoms that you are haveing with my mach z. A quik fix is to flip the reeds upside down and hopefully that should solv the problem, it did for me.
 
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