theneil Posted June 9, 2012 Report Share Posted June 9, 2012 So im waiting for me new serval cub cylinders, noss head, wiesco pistons and 4 mil crank from F.A.S.T, and Id like some feedback about what i should do for the carbs. >> backstory It was running great (except i never set the idle correctly so it would die if you let it sit idleing) with stock jugs, V force 2 reeds, toomey t5s, and a .030 overbore, but last time i rode it the right cylinder liner broke at the bottom, boogering up the piston (on one side) and the crank and rod bearings and the head and the jug. Thats why i got the above parts. What should i do about the carbs? would i be able to do the first part of a break in with the same jets in the stockers? Should i re jet to really rich before i even try to kick it over for the first time? Any ideas of what jets to start with (and needle position? Or should i spend the last of my hard earned dollars on larger carbs and jet those to my conditions? And if i do that what size/model should i buy? i would also like to start using more oil, in the 24-28 to 1 range (i was running it 32 to 1 previously) will that affect my jet size? ,I am new to this forum, but i searched alot and thats how i came to choose my other parts and where to buy them at, but not much info about the carbs. any help would be great. Bike specs Im running klotz techniplate, 5000 ft elevation, k and n filter with some sort of oval adapter, v force 2 reeds, stock ported serval cub cylinders (68/58 4 mil) hotrods 4 mil stroker crank with the f.a.s.t. treatment, toomey t5s and a noss cool head with 24cc domes, an adjustable timing plate and a F.a.s.t. clutch. Im 200 lbs and i live in the mountains, so there is a lot of hilly trails. but the dunes are only an hour and a half away, so ill be riding those too. Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted June 9, 2012 Report Share Posted June 9, 2012 Run the stock carbs for now. Rebuild them, do a TORS Elimination get a sync tool from FAST and a cheap Tach from eBay. Why are you running so much oil in the pre-mix? The more ppm, (parts per million) of oil you have in your pre-mix the less fuel you have to burn. You should be fine with 40:1, that's 16oz or 1 pint to 5 gallons of fuel. Speaking of fuel, what octane are you running. I would imagine #30 pilots, 340 mains and stock needles, middle clip. Why didn't you ask Jeff at FAST about carbs and jetting? Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted June 9, 2012 Report Share Posted June 9, 2012 i ran 27.5 pilots with 340mains stock needle in middle clip in my stock carbs on 421 serval with t5's at sea level and 70f temps. bigger carbs will wake the bike up for sure, tho the lil carbs offer pretty awesome throttle response. speak to jeff at fast, he'll hook you up on carbs. Quote Link to comment Share on other sites More sharing options...
rjdgriff Posted June 9, 2012 Report Share Posted June 9, 2012 Jeff at fast is the guy to talk to for sure. I havens t5s in area code 66086 with 27.5 pilots and t5jets and needle and she ran great. But I upgraded pipes to original rockets and carbs to 35 pwks and I'm happy as fuck. Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted June 9, 2012 Report Share Posted June 9, 2012 There you have it.If DDU ran 27.5s and 340s at sea level then you know you'll be fat and can work down.You'll probably end up on 27.5s and 310s-320s due to your elevation of 5000'.Lean out one size main jet for every 2000' of elevation.Which flavor Techniplate are you mixing?Find it and mix it accordingly...http://www.klotzlube.com/Tech_Sheets.asp Quote Link to comment Share on other sites More sharing options...
rjdgriff Posted June 9, 2012 Report Share Posted June 9, 2012 I also had/have 421 serval. And I now run 32:1 klotz Quote Link to comment Share on other sites More sharing options...
theneil Posted June 9, 2012 Author Report Share Posted June 9, 2012 Thanks for all the advice, I forgot to ask jeff when i was on the phone with him last, but i was looking for a few opinions. I suppose im going to stay at 32 to 1, but it says in the clymers manual 24-1 But it also says to use 10w-30 in the trans and its the klotz super techniplate Fast racing recommends Quote Link to comment Share on other sites More sharing options...
rjdgriff Posted June 9, 2012 Report Share Posted June 9, 2012 Jeff says to use klotz at 32:1. That's is what he recommends. Quote Link to comment Share on other sites More sharing options...
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