BB-banshee171 Posted January 6, 2014 Report Share Posted January 6, 2014 Ok I've got a 421 serval, which I'm sending to have dune ported, I have 35 pwks, what jetting should I start out at? I looked in the carbs and they have 42 pilots with 158 mains. Any help would be greatly appreciated so I don't buy more jets than I have to. Quote Link to comment Share on other sites More sharing options...
BB-banshee171 Posted January 6, 2014 Author Report Share Posted January 6, 2014 I'm sorry 152 mains Quote Link to comment Share on other sites More sharing options...
dave5.0 Posted January 6, 2014 Report Share Posted January 6, 2014 Few sizes up on the pilot. Main Shouldnt be much bigger I doubt. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted January 7, 2014 Report Share Posted January 7, 2014 48 pilot 160 main t I start Quote Link to comment Share on other sites More sharing options...
lms1977 Posted January 7, 2014 Report Share Posted January 7, 2014 Yea I was gonna say 48 pilots and 155-165 to start should put you in a safe spot to start Quote Link to comment Share on other sites More sharing options...
BB-banshee171 Posted January 7, 2014 Author Report Share Posted January 7, 2014 Thanks guys Quote Link to comment Share on other sites More sharing options...
Young Guns Racing Posted January 23, 2014 Report Share Posted January 23, 2014 Yea I was gonna say 48 pilots and 155-165 to start should put you in a safe spot to start X2, very good advice here. Quote Link to comment Share on other sites More sharing options...
uman1030 Posted January 23, 2014 Report Share Posted January 23, 2014 X2, very good advice here. cool saved me some time! Guess this is were i will start on mine as well. still waiting on engine to be shipped back but i got some 35's pwk's sitting here to put on mine as well. I've Become very familiar with the stock carbs and jetting but id like to have a descent starting point to save some time with the new carbs. My yz 250 uses a keihin carb so im no stranger to keihins and i have some spare jets. iirc i have a 55/180 in the YZ but it doesn't have quite the same needs as the shee obviously as its a single cylinder/carb. this is a good starting point atleast thanks. Quote Link to comment Share on other sites More sharing options...
BANSHEE HP Posted January 23, 2014 Report Share Posted January 23, 2014 Isn't a serval "dune" ported as cast? 1 Quote Link to comment Share on other sites More sharing options...
uman1030 Posted January 23, 2014 Report Share Posted January 23, 2014 Isn't a serval "dune" ported as cast? Dont believe so, Jeffs making mine a 421 serval and he made no mention of it being a dune port. think its ports are very conservative as cast. Edit: I stand corrected. Quote Link to comment Share on other sites More sharing options...
RadarRacing Posted January 24, 2014 Report Share Posted January 24, 2014 A serval basically is a dune ported cylinder. Doesnt mean Jeff cant help with porting and domes and gain everywhere. Most servals I have seen did not like much timing and ended up at the smaller size of what normally is ran in a specific carb. So it may like even smaller than the normal 155 jet in 35s. Your yz dirtbike probably also has a 39mm carb not a 35. 39s need to run bigger jets. Quote Link to comment Share on other sites More sharing options...
rjdgriff Posted January 26, 2014 Report Share Posted January 26, 2014 On my fast 421 serval I was running +4 timing vf3 and 35 pwks with 24cc domes. My jetting was at 48 and 155 in the summer and 165 in the winter. Elevation is at 1100 Quote Link to comment Share on other sites More sharing options...
uman1030 Posted January 26, 2014 Report Share Posted January 26, 2014 A serval basically is a dune ported cylinder. Doesnt mean Jeff cant help with porting and domes and gain everywhere. Most servals I have seen did not like much timing and ended up at the smaller size of what normally is ran in a specific carb. So it may like even smaller than the normal 155 jet in 35s. Your yz dirtbike probably also has a 39mm carb not a 35. 39s need to run bigger jets. ya I wasn't comparing jetting since its a single compared to duals not to mention a diffrent dispacement. just noting I'm familiar with the carb type. And have a bunch of spare jets. And meant the post above was a good starting point. Not what's in my dirt bike. edit: gotch ya serval will probably like less jetting then the cub ill start at about 155 and work down till its right. Sent from my Galaxy Nexus Quote Link to comment Share on other sites More sharing options...
1bad4millbanshee Posted December 3, 2014 Report Share Posted December 3, 2014 These servals on oump gas? Quote Link to comment Share on other sites More sharing options...
Derrickc14 Posted September 12, 2015 Report Share Posted September 12, 2015 (edited) On my fast 421 serval I was running +4 timing vf3 and 35 pwks with 24cc domes. My jetting was at 48 and 155 in the summer and 165 in the winter. Elevation is at 1100 What needle and position of needle did you have your in? Edited September 12, 2015 by Derrickc14 Quote Link to comment Share on other sites More sharing options...
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