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help please

what will be my starting jetting be for this mikuni vm roundslide 28mm carb, mods are in my sig and does it take the stock blaster jets?
 
http://www.blasterforum.com/engine-13/mikuni-52703/
 
1989 yamaha blaster
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Re: help please

Reply #1
The VM28 and the stock VM26 are going to be VERY close to the same setup.  Depending on your elevation, you'll probably end up at a 32.5 pilot and a 290-300 main.
Click on the pic VVVV You know you want to....


Re: help please

Reply #2
The VM28 and the stock VM26 are going to be VERY close to the same setup.  Depending on your elevation, you'll probably end up at a 32.5 pilot and a 290-300 main.

since its a bigger carb does it take smaller main jets? and it takes the exact same jets as a stock carb right?
thanks
1989 yamaha blaster
 braaap

Re: help please

Reply #3
I BELIEVE the entire VM series uses the same tiny pilot and 6mm hex "short" mikuni jets.

Larger carburetor isn't necessarily going to mean smaller jets.  Only under complete WOT is the carburetor throat any larger at all (and even then we're only talking 2mm or less than 1/8").  The vacuum signal in the VM28 should be VERY similar to the stock VM26 (same basic design with interchangable parts) so the jetting should be VERY similar.
Click on the pic VVVV You know you want to....


Re: help please

Reply #4
I BELIEVE the entire VM series uses the same tiny pilot and 6mm hex "short" mikuni jets.

Larger carburetor isn't necessarily going to mean smaller jets.  Only under complete WOT is the carburetor throat any larger at all (and even then we're only talking 2mm or less than 1/8").  The vacuum signal in the VM28 should be VERY similar to the stock VM26 (same basic design with interchangable parts) so the jetting should be VERY similar.

should the jetting be any different, ehh F it ill just throw in a 300 and see how it runs for now, but what confuses me is the guy before me had similar mods to me and said he had a 180 main jet in? maybe he ment to say 280?
1989 yamaha blaster
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Re: help please

Reply #5
He either meant to say 280 (believable) or he had a keihin 180 main (WAYYYYY TOO large) in it.  There really is no way to tell now.
Click on the pic VVVV You know you want to....


Re: help please

Reply #6
He either meant to say 280 (believable) or he had a keihin 180 main (WAYYYYY TOO large) in it.  There really is no way to tell now.

hes gonna reply back with more info on it..
1989 yamaha blaster
 braaap

Re: help please

Reply #7
I BELIEVE the entire VM series uses the same tiny pilot and 6mm hex "short" mikuni jets.

Larger carburetor isn't necessarily going to mean smaller jets.  Only under complete WOT is the carburetor throat any larger at all (and even then we're only talking 2mm or less than 1/8").  The vacuum signal in the VM28 should be VERY similar to the stock VM26 (same basic design with interchangable parts) so the jetting should be VERY similar.

I agree with James! no change in jetting.