Jump to content

Upgrading to 28mm PWK's from Stock Carbs


Mackington

Recommended Posts

Hello Everyone!

So just as I dialed in the jetting on my stock carbs I found a deal on a pair of 28mm Keihin PWK's. My question is where do I start with jetting?

Current Stock Carb Settings:

#27.5 Pilot Jets
#350 Main Jets
#4 Toomey Needle Position (from bottom)
Air Screws 1.5 Turns Out

Here is my list of Engine Work from the CT Racing 400cc Stroker Kit:

Toomey T5 Pipes
Toomey Perfect Jet Kit Needles
TORS Removal Kit & Carb Caps
Vito’s Hemi Head V (Pro Design 19cc Domes Cut for 4mil)
Timing plate (set @ zero for 91 pump gas)

Pro-X Blaster pistons

MX Porting

Hot Rods 4Mil Crank
CFM Aluminum Air Box (No Lid)
K&N Pod Air Filters with Pre-Chargers
Chariot Billet Intake Manifold
VForce 4 Reed Cages

OTHER VARIABLES:

Altitude 5,258ft (Colorado)

Temperature: 65 Degrees

Compression: 150-155psi

 

Thanks in advance!!

 

Edited by Mackington
Link to comment
Share on other sites

u talking about those ones on fb for 275 with filters? if so good deal they look clean.

also im curious to see who will be the first to comment on the t5s 

most run a jjh needle i think in the 28s... 45 48 50 pilots and some 145 148 150 152 155 main jets. I could be way off bc ive never tuned 28s before only 35s and stockers.  But its prolly gunna be  around there some where.  Start fat on the main and work it down. 

Edited by Ayesully810
Link to comment
Share on other sites

10 minutes ago, Mackington said:

Thanks @Ayesully810 ! That's exactly what I was looking for. I needed an idea of what range of jets to buy lol.

These are indeed the carbs from the swap page haha. Sick of the ripping the stock ones apart!

yeah when i had my 35s i just bought an assortments of everything  40-58 pilots  and 135-160 main jets  that way its all covered.  Good luck post some pics of the new motor too

Link to comment
Share on other sites

Cool thanks again! I'll post updated pics ASAP.  Are there specific part numbers I should be looking for? I am finding TONs of different ones haha.

I usually order jets through Vito's Performance. Do these part #'s seem right?

https://www.vitosperformance.com/atv_parts/product.php?productid=700&cat=222&page=1

https://www.vitosperformance.com/atv_parts/product.php?productid=726&cat=222&page=1

Link to comment
Share on other sites

I second Tony's answer. One of my bikes is a stock stroke dune ported with the rest of the mods the same as yours on 28 PWKs. I settled on 48 pilot, 152 main and jjh middle clip. I bought pretty much the exact range of jets that were suggested. Jetsrus is a good source also, I've bought tons of jets from them in the past.

 

Link to comment
Share on other sites

Just now, Mackington said:

Thanks @97Screamer ! I just ordered a bunch from RMATV. They had them for pretty cheap! I will report back with my findings.

Were you able to find jjh needles on RMATV? I recently ordered some through Jetsrus because I couldn't find them on RM. I forgot how much paying for shipping sucks!

 

Link to comment
Share on other sites

3 minutes ago, 97Screamer said:

Were you able to find jjh needles on RMATV? I recently ordered some through Jetsrus because I couldn't find them on RM. I forgot how much paying for shipping sucks!

 

Lol yea the shipping adds up! I did not find those needles but I did find the mains and pilots I needed. I called the guy who built my motor at CT Racing and he said to use the Toomey needles I have in the new PWK's. He also mentioned I should start at 35 Pilot and 140 Main for this motor at my altitude.

Edited by Mackington
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...