[jzevorich]

Hi all!
I have a 2004 Yamaha VStar 650 Classic. (My first bike) I've been riding almost a year now, and I want to upgrade my bike. I'm turning it into a bobber with some 14" apes...lol

My first step is upgrading my exhaust, my air intake, and rejetting my carbs.
I hear good things about Vance and Hines, and I would like to go with the Shortshots or the Cruzers (which they don't make anymore, but I can get them off Amazon)
I would prefer the Cruzers, because I think they sound better. (I know, my bike is only a 650, but hey, what the hell)

My question is this: What air kit and rejet kits do I need that are most compatible with my bike and the V&H Cruzers?

 

[SemiFast]

Hi all!
I have a 2004 Yamaha VStar 650 Classic. (My first bike) I've been riding almost a year now, and I want to upgrade my bike. I'm turning it into a bobber with some 14" apes...lol
My first step is upgrading my exhaust, my air intake, and rejetting my carbs.
My question is this: What air kit and rejet kits do I need that are most compatible with my bike and the V&H Cruzers?

The exhaust system doesn't make a lot of difference but the "air kit" could, or will, make a big difference when it comes to carburetor tuning (jetting) the V-Star 650.
If you're thinking to increase the amount of intake air flow, the Kuryakyn Hypercharger will do that. I'm sure there are others on the market also. Or, you could modify the original air box by removing a substantial amount of plastic on the back side (removing the air restriction) as a way to greatly increase air flow and retain the original air filter type.
I've done them both ways.
You'll have to study the original air box to understand what, how much and where to remove plastic if you go that route. YouTube might help with that.

I like Factory Pro jet kits because they are straight forward WITHOUT a bunch of changes done just for the sake of change.
You'll need to buy main jets large enough (around 5 ~7 steps over stock size) to compensate for the air increase because the jet kit was intended for a stock air system but you will need the adjustable jet needles the jet kit comes with.
To get it right you will have to learn how to "read" spark plugs if you don't already know.... The good news is spark plugs are easy to get to on your machine.

S F

 

[slick nick]

https://www.650ccnd.com/perf.htm best and only place for modding the 650, that i know of..

 

[Frank94]

Hi
I have a 2009 Yamaha vstar 650 that I decided to upgrade its air box with a cold air intake. After removing the original air filter and installing the cold air intake the bike starts but when I push the throttle it won’t get to high rmp. Like it can’t get enough gas or air. Anyone one know what’s the problem ? I also tried to reset the ecu but it didn’t work.

 

[SemiFast]

I decided to upgrade its air box ........ when I push the throttle it won’t get to high rmp ....
.... Anyone one know what’s the problem ?

You'll need to buy main jets large enough (around 5 ~7 steps over stock size) to compensate for the air increase because the jet kit was intended for a stock air system but you will need the adjustable jet needles the jet kit comes with.

^ Depending on how much you increased the air flow / air inlet size.

S F

 

[slick nick]

you can buy jets separatly from a kit, main jets cost about $5.00. you might have a knotched needle or you can shim it. size.02 washers usually one is enough. you raise the needle to enrichen. the pms screw can be turned out to increase richness in low rpm range.and the pilot jet can be changed one size up. you have problems in the higher rpm range so look at changing the main jets.when you have a problem try increasing the choke and see if it helps.. jets r us is a good place for jets.a kit will give you probably three different sized main jets so it might be easier to narrow it down. 650 CC & D

 

[Frank94]

What if I upgrade the exhaust? Dose it help if I make them bigger ?

 

[slick nick]

no.when you increase the air going into an engine you increase the jets to keep a proper air to fuel ratio. Changing to performance pipes can make the engine lean at wide open throttle, so you can up the main jet one size because the mains come into play at higher rpms.

 

[SemiFast]

I decided to upgrade its air box with a cold air intake

I'm not familiar with the term cold air intake. Can you tell us exactly what that is?
It will help us (me) understand what changes were made and what might need to be done.

S F

 

[Frank94]

Cold air intake is an aftermarket air filter that is larger than the original filter and take more air into the engine. Do you know where I can find the exact main jet for the carburetor? I found out the original one is #90 and I need to replace it with #130 but I don’t know where to get it. Is there any store where I can pick it up instead of delivery ? I’m in oc California

 

[SemiFast]

V-Star 650's are popular in my area; I know the bike well. I've performance tuned quite a few of them.
By my count a #130 main jet is sixteen steps larger than the stock #90!
There is no way you are going to need main jets that large no matter what type of air box, air filter, air inlet and or exhaust mod's have been made. NO WAY.
See my post number two above. The information there applies to your machine.
You should be able to buy Mikuni main jets from most any M/C shop.

BTW,
Mikuni main jets are numbered in steps like this: 90, 92.5, 95, 97.5, 100, 102.5, 105, 107.5, 110, 112.5 and so on.
You can probably expect to be in the range in red above, depending.

S F

 

[slick nick]

Cold air intake is an aftermarket air filter that is larger than the original filter and take more air into the engine. Do you know where I can find the exact main jet for the carburetor? I found out the original one is #90 and I need to replace it with #130 but I don’t know where to get it. Is there any store where I can pick it up instead of delivery ? I’m in oc California

V-Star 1100 Wiki Knowledge Base - Carb Jetting the main jets are called small round..harley shops sell them,

 

[Frank94]

I got the main jets (#105) but they don’t fit In the holes they suppose to go. Also I don’t see any difference between the new main jets And the original ones except the head of the new main jets are larger and that’s why they don’t fit in their place.

 

[slick nick]

i'm sorry i gave you information for jets for the 1100 i thought the 650 was the same.makes me an idiot.

 

[Frank94]

I got the main jets (#105) but they don’t fit In the holes they suppose to go. Also I don’t see any difference between the new main jets And the original ones except the head of the new main jets are larger and that’s why they don’t fit in their place.

 

[SemiFast]

I got the main jets (#105) but they don’t fit In the holes they suppose to go. Also I don’t see any difference between the new main jets And the original ones except the head of the new main jets are larger and that’s why they don’t fit in their place.

Clean the head of the original jets and look for a number. It should be 90. According to the parts diagram it could be 91.5 for some year models. That is an oddity and not important at this point.
Hard to see the difference (in the hole) between the two when one is new and clean and the other is old and tarnished. Different numbered jets are different sizes.
As you probably already figured out you need the 'small head" type jets...

S F

 

[Frank94]

I changed the main jets to size 105 as you said but I still have the same problem. When I push the gas it chokes. So I think I have to use jets 130 as I said before

 

[SemiFast]

I'm not familiar with the term cold air intake. Can you tell us exactly what that is?

Cold air intake is an aftermarket air filter that is larger than the original filter and take more air into the engine.

Would still like to know... Exactly what that is. Might help.
Also, you might have something other than a tuning requirement happening.

S F

 

[Critter]

In theory a cold air intake pulls in ambient air away from the engine. In my sportscar I pull air from between the intercooler and the grill. On a twin it is usually out in front of the carb with a larger 'ram effect' air cleaner. You can see pictures of various ones on this PAGE

 

[SemiFast]

Yes. My main question is how free flowing (lack of restriction) is this cold air intake.

S F