Mackington Posted February 5, 2018 Author Report Share Posted February 5, 2018 Agreed! They look sharp Quote Link to comment Share on other sites More sharing options...
Mackington Posted February 12, 2018 Author Report Share Posted February 12, 2018 Update! I finally have my jetting dialed in on these 28mm PWK's (for the colder weather at least). Due to the general lack of high altitude specific jetting information on the web I have posted my engine / jetting information below. Hope it can be helpful! Altitude: 5,277 Feet Temperature: 50 Degrees ENGINE INFORMATION: Keihin 28mm PWK Carbs #40 Pilot Jets #140 Main Jets Toomey Needles #2 Needle position from bottom Idle Screw almost 100% in VForce 4 Reed Cages Chariot Billet Intakes CFM Aluminum Air Box (No Lid) K&N Filters & Pre-Chargers Hot Rods 4mil Crank Vertex 66mm Blaster Pistons (#22569) Vito's Hemi Head V Pro Design 19cc Domes (Cut for 4mil crank) NGK BR8ES Spark Plugs I still need to smooth out the off-idle a bit with air screw adjustments. Other than that though the WOT plug chop looked great! I still need to perform another midrange plug chop though just to be sure it's all dialed in. Everything seems to be running great! *EVERY MOTOR IS DIFFERENT. START RICH AND WORK DOWNWARD* Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted February 13, 2018 Report Share Posted February 13, 2018 sweet good stuff Quote Link to comment Share on other sites More sharing options...
Mackington Posted February 15, 2018 Author Report Share Posted February 15, 2018 I was able to fix the sluggish off-idle with the air screw! They are both all the way screwed in right now and it's idling/revving perfect. I'll have to tweak these again though when I install these new metal idle screws. The plastic ones that come on the PWKs are bullshit! Next up is one last round of plug chops on the Pilot, Mid-Range, and Main circuits. I'll perform these plug chops and post pics when the weather gets warmer. It will likely be a little rich when it warms up since I've been jetting in 50-60 degree temps. Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted February 15, 2018 Report Share Posted February 15, 2018 if you have to screw your air screw all the way in for it to run right (not the plastics idle screws, the brass screw), you are gunna wanna up your pilot a size or 2 Quote Link to comment Share on other sites More sharing options...
JKJK Posted February 15, 2018 Report Share Posted February 15, 2018 Viewing your jetting specs your pilet looked lean to me.Confirming this is the fact that the air screw is in all the way.I would up the pilets at least one size,center the air screw,and dial in as needed.Also i was not aware toomey had needles available for 28 pwk's.I have always had good results from useing the jjh needles. Quote Link to comment Share on other sites More sharing options...
Mackington Posted February 16, 2018 Author Report Share Posted February 16, 2018 Yea I was thinking the same for pilot. Bumped it up to achieve idle at 5k when syncing carbs. May go up one more size to be sure. I’ve yet to plug chop the #40 pilots.The jetting specs I got straight from CT Racing. Same with the Toomey needle recommendation. I’ll see how that goes though when I plug chop the mid range. Worst case I have JJH needles laying around. He recommended starting at #35 pilots but plug chops came back pure white which is why I bumped up to #40 pilots. The plug chop I did on the #140 mains looked perfect at least haha. Getting there! Warmer weather will definitely richen it up. It’s been in the 50’s here lately. Quote Link to comment Share on other sites More sharing options...
Mackington Posted February 18, 2018 Author Report Share Posted February 18, 2018 Went riding today and for the most part it ran great! However I did have a plug rattle loose. May be paranoid but I’ll try jumping up the mains a size or two. Plug chops looked perfect in the same temps but better safe than sorry. Quote Link to comment Share on other sites More sharing options...
Mackington Posted April 26, 2018 Author Report Share Posted April 26, 2018 Finally got my jetting dialed in perfect! Plug chop verified. Fires up first kick every time now! Here are my settings: ELEVATION: 5351 Feet CARB SETTINGS: (55 - 75 Degrees Faranheight): 28mm Keihin PWK Carbs 91 Octane Pump gas @ 32:1 (Castor 927) #40 Pilot Jets #142 Main Jets Toomey Needles #2 Needle Position (from bottom) Idle Screw almost 100% in ENGINE: (CT Racing 4 mil Stroker): MX Porting by CT Racing Toomey T5 Pipes & Silencers NGK BR8ES Spark Plugs VForce 4 Reed Cages Chariot Billet Intakes CFM Aluminum Air Box (No Lid) K&N RU-0700 Filters & Pre-Chargers Hot Rods 4mil Crankshaft Vertex 66mm Blaster Pistons (22569) Vito's Hemi Head V -Pro Design 19cc Domes (Cut for 4mil crank) -160 psi per cylinder DISPLACECMENT: 396.86cc Bore x Bore x Stroke x Constant / 2 66 x 66 x 58 x .0031416 = 396.8594 Hope someone finds this helpful! Quote Link to comment Share on other sites More sharing options...
Mackington Posted May 19, 2019 Author Report Share Posted May 19, 2019 Hey Everybody! Recently tuned my carbs again and FINALLY got it dialed in 100%. I installed #42 Pilots and a JJH Needle on the middle clip. Now it idles and rips smoothly throughout the whole powerband. I suspect the Toomey needles I had in there initially were slightly too lean along with the pilot jet. Anyways here is (hopefully) my final jetting setup for my 4mil: ELEVATION: 5351 Feet TEMPERATURE: 60 Degrees Faranheight ENGINE: (CT Racing 4 mil Stroker): MX Porting by CT Racing Toomey T5 Pipes & Silencers NGK BR8ES Spark Plugs VForce 4 Reed Cages Chariot Billet Intakes CFM Aluminum Air Box (No Lid) K&N RU-0700 Filters & Pre-Chargers Hot Rods 4mil Crankshaft Vertex 66mm Blaster Pistons (22569) Vito's Hemi Head V -Pro Design 19cc Domes (Cut for 4mil crank) -160 psi per cylinder CARB SETTINGS: (55 - 75 Degrees Faranheight): 28mm Keihin PWK Carbs 91 Octane Pump gas @ 32:1 (Castor 927) #42 Pilot Jets #142 Main Jets JJH Needles #3 / Middle Needle Position Idle Screw 50% in Air Screws 1/2 Turn Out The picture attached is a plug chop performed 1st - 6th gear / Wide Open Throttle https://imgur.com/a/Xt2Jbmq Quote Link to comment Share on other sites More sharing options...
gusto Posted May 21, 2019 Report Share Posted May 21, 2019 Good stuff Quote Link to comment Share on other sites More sharing options...
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