Mikuni VM28 flat slide carb jetting starting point.

[SIR69]

I have a 2006 Blaster with following options and I am wondering if anyone has used a Mikuni VM28 flat slide carb, and knows any jetting starting points.
I have : DG national header
FMF Power Core 2 silencer
Hot rods stroker crank
68mm bore
1800ft elevation
K&N fiter, stock box no lid
stock timing
race fuel
Mild port job

Any info or opinions would be greatly appreciated.

 

[Blaaster]

#290 main.
#32.5 pilot
Needle middle clip

Plug chop to confirm.

You are wasting money buying race fuel, it is not needed with your mods!

The DG header is not doing the mild port job any favours.

 

[SIR69]

Thank you for you quick reply. When I look at Mikuni's web site the show the stock jets for this carb as a 180 main and 15 pilot? Are these numbers some other type of jet size? This carb does not use same jets as stock blaster carb. Also head is cut and rechamberd pretty close, and I have a good supply of race fuel is why I use it. DG header is just what came on quad, would you recommend replacement with......? I am still putting this build togeather and just trying to get everything i might need to rejet and plug chop when it gets going. This carb fits perfect on boot and air box, and eliminates tors and switches to twist throttle (go ahead tell me its dangerous, I like it), but I have several stock carbs as well and if I am wasting my time I will just use one of those. This site has well documented jettings for stock carb. I am not doubting you because you seem like the man to listen too on this site, just making sure I understand you correctly. Thanks again.

 

[Blaaster]

Oops my bad, (just woke up) they do use different jets than the stock carb.

I saw no mention of head work in your post, that is why I commented on the race fuel.

If the compression has been raised by the head work then you may be on the right track with the higher octane fuel!

In no way will I knock the use of a twist throttle, I use one myself.
In the hands of the experienced rider, they seem to be a bonus.

Depending on what you wish to ride will determine your choice of header.

If you are looking for power in the low/mid region, the stock carb has been known to shine.

 

[SIR69]

Low to mid is what I am after.....could you offer any jet sizes for this carb though?

Would FMF fatty header be an upgrade to the DG?

 

[Blaaster]

I am not conversant with the 28 flat slide as I have not used one, I am therefore reluctant to comment.

If you are after low/mids a DMC Alien would be a good choice with the stock 26mm carb.

 

[speedyslyder]

just wait others will post. there is other threads on this carb somewhere to.fmf is a low to mid pipe yes.
what is compression at with head mod?
advancing the timing i believe will give more low end as well
changing sprocket size option too

 

[SIR69]

Engine is still being assembled... I will post compression after break in..
I am thinking of going up a couple teeth on the rear being as my ass dyno is a little heavier than others, and slotting the stator plate for timing is no prob. I am thinking that that is necessary for the fuel anyway..... Thanks for the replies

 

[Blaaster]

Fitting a spacer plate between the reeds and the cylinder tends to move the power to come on earlier!