apeik Posted August 7, 2014 Report Share Posted August 7, 2014 setup is: 421 serval as cast, brand new. pump gas domes from redline cut for this setup .050 squish, 152 psi each hole cpi sb inframe pipes stock cages with boyesen reeds wicked billet intakes(sealed to death with 1211) passes leakdown 6psi for 8 mins zero loss 35mm pwk carbs 55 pilot, cel 3rd/4th clip, 175 main(float hight checked, everything inside spotless) 700 ft elev. 70-80 degrees San Diego, CA All genuine Keihin jets Now this is about as basic of serval setup as they come minus the reeds. I bought the carbs new from fast about a year ago, and from the day i got them they have wanted retarded huge jetting or bike is way to lean(ate a set of pistons to find this out). It jets out like pwk 39mm's, I've checked more than once and they are 35's. Now a bit of backstory the motor i had before this was a passion ported cub, neverending problems including the jetting being crazy. With that setup it ended up running good finally with 175 mains, dgk needles on the 5th...yes 5th clip and 55 pilots. I assumed it was something to do with the retard port job that cub came with. Well now im running basically the same setup as tons of other people, and I'm having to use Huge jets, even compared to a friend with the same identical setup minus reeds and his bike wont rev out with anything over a 155 main, and smokes like a banshee. Mine barely smokes with 175 mains, 55 pilots. I know my way around this bike pretty decent, but it makes no sense and feels like there's either something wrong with the carbs or possibly reeds. Now i suppose as long as it jets out and runs good it shouldn't matter, but it bothers me. Has anyone else ever seen anything like this? Sorry for the long winded post, and thanks in advance for any insight. -Aaron Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted August 7, 2014 Report Share Posted August 7, 2014 U need to do a proper plug chop but that's not the first serval I heard of that high on jetting I tuned one with similar mods perfect chop at 172 / 52dgh 2nd clip and about 6 months back same basic set up just shearers I chopped down to a 165 /55 cel 4th clip every motor wants what it wants do chops keep it safe and trust your plugs , I have jetted 421 cubs that take less fuel then some servals Quote Link to comment Share on other sites More sharing options...
apeik Posted August 7, 2014 Author Report Share Posted August 7, 2014 (edited) Ya, i need to do a plug chop, but i dont have room to get out of third gear at my shop without getting it impounded. When it was on the dyno at shearers with the cub cylinders on it, is when it was at 175 main, dgk 5th clip, 55 pilot at 3k alttitude and he said the jetting was good. Course it only made 82hp and was slipping the shit out of the clutch, now it's got a lockup. i might try to swap carbs, prolly best direct way. Edited August 7, 2014 by apeik Quote Link to comment Share on other sites More sharing options...
apeik Posted August 7, 2014 Author Report Share Posted August 7, 2014 ya, im guessing it'll be pretty obvious if it's the carbs causing it to be lean naturally. his smokes like crazy with 48/155's sitting in the garage. Quote Link to comment Share on other sites More sharing options...
apeik Posted August 7, 2014 Author Report Share Posted August 7, 2014 So i was brainstorming last night.. came into work and pulled the right cable adjuster boot up...and took a pic...appears they havnt been opening all the way with this stretched cable. Quote Link to comment Share on other sites More sharing options...
apeik Posted August 7, 2014 Author Report Share Posted August 7, 2014 They weren't outta sync..I pulled the boot on the right side up off the adjuster.. and took a pic to show they don't open 100%. cable so stretched that with the adjusters on their last thread they still don't open 100%. guessing I was never running fully on the main? 1 Quote Link to comment Share on other sites More sharing options...
apeik Posted August 7, 2014 Author Report Share Posted August 7, 2014 this is with adjusters ran 1 thread from falling out. still till not completely open it appears Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted August 7, 2014 Report Share Posted August 7, 2014 this is with adjusters ran 1 thread from falling out. still till not completely open it appears Try modding your thumb throttle and adjusting both ends of the cable properly. ( thumb side and carb tops) Between the modded throttle and adjustments you should be able to open 40s if need be. Quote Link to comment Share on other sites More sharing options...
apeik Posted August 7, 2014 Author Report Share Posted August 7, 2014 It's a twist..don't have any way to mod it..ordering the longer adjusters in a few minutes. it's the cable from the 2 into 1 part that's just to long Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted August 7, 2014 Report Share Posted August 7, 2014 It's a twist..don't have any way to mod it..ordering the longer adjusters in a few minutes. it's the cable from the 2 into 1 part that's just to longGotcha. I bet when get them opened 100% you'll drop some on the mains.Also a lot of guys find the cel needles to run a little cleaner than the "D" series needles on cub/serval cyls. Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted August 7, 2014 Report Share Posted August 7, 2014 Just re-read your post closer...saw you already have a CEL not the DGK. Fwiw , a CEL is a shorter needle than a DGK. Quote Link to comment Share on other sites More sharing options...
apeik Posted August 7, 2014 Author Report Share Posted August 7, 2014 ordered the longer adjusters, so should be able to get them to open all the way when they come in. Turns out my friends carbs were opening about 80% or so as well, but he had the longer adjusters, and they were so far adjusted down they were hitting the slide on the top to the adjuster . I need more room to chop out the main and see where it ends up. Quote Link to comment Share on other sites More sharing options...
apeik Posted August 7, 2014 Author Report Share Posted August 7, 2014 picture of my friends carbs pulled wfo for the lolz picture of what mine looks like if you pull the cable up while wide open..so they do go up quite a bit Quote Link to comment Share on other sites More sharing options...
hp2000 Posted August 7, 2014 Report Share Posted August 7, 2014 Oh wow.. Quote Link to comment Share on other sites More sharing options...
apeik Posted August 7, 2014 Author Report Share Posted August 7, 2014 he had to adjust his idle stop on his chariot housing to allow full love mentioned up and down. This is after it was all fixed up Quote Link to comment Share on other sites More sharing options...
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