Gumball12 Posted May 6, 2015 Report Posted May 6, 2015 I am having trouble finding anyone with the same specs for a guide to start jetting. I would like to have options on the bench before I get it going. I have 28mm pwk, Shearer SB, V-Force 4, Seval Wampus. I am at sea level about 90 degrees. I currently have 162, 160, 158, 155 mains and 50, 48, 45 pilots. jjh needle 22cc domes, +4, .047 squish Quote
Gumball12 Posted May 6, 2015 Author Report Posted May 6, 2015 I don't have that luxury where I am at or at least on with jets instock. That is a good idea though Quote
RadarRacing Posted May 6, 2015 Report Posted May 6, 2015 You are probably close with the jets you have. Serval are quite different to tune sometimes. Dont use cub domes BTW. I think you will be in the 155 to 160 range but start with the biggest. Ideally start even bigger than your 162. Like 168 and start working dow. Do a proper plug chop and report back. 1 Quote
Gumball12 Posted May 6, 2015 Author Report Posted May 6, 2015 The domes I have were cut for serval. But ? What is the difference between the two? One set I have has a larger squish band than the other. Quote
trickedcarbine Posted May 8, 2015 Report Posted May 8, 2015 It's possible you may wind up with a low 150's or high 140's main since the 28's are a bit small and will have a pretty potent signal. 1 Quote
Gumball12 Posted May 8, 2015 Author Report Posted May 8, 2015 That what I was thinking. I am going to start at 162 and work down. When I get close it is time for the dyno Quote
RadarRacing Posted May 8, 2015 Report Posted May 8, 2015 Honestly 28s dont hold the smaller servals back as much as you'd think. I know of a 421cc serval that made 83hp with stock carbs and yet only 85hp with 35s and 86hp with 38mm. For pumpgas domes the CUB domes used in servals have caused some detonation issues with some pipe/ dome/porting combonations. Serval domes for pumpgas work better with less compression than what are common CUB pumpgas domes. Same for race gas domes. 1 Quote
trickedcarbine Posted May 8, 2015 Report Posted May 8, 2015 Plenty of 75+hp stuff out there now on the smaller pwk's Quote
Gumball12 Posted May 8, 2015 Author Report Posted May 8, 2015 I stayed with smaller carbs hoping for quicker response. I am not trying to get the big numbers just looking for the best curve. I am at 170psi on both sides cold before break in or starting it. I do plan on race gas. Right now I have vp110 mixed 50:50 with 93. I think I will be alright. I got the dome cut from driveline. The ones I installed. The ones that came from BP have a lot larger squish band and were manufactured in kalispell mt by vortec. I have not heard of them but they look just like the pro design ones I used with the old motor. leak down passed squish good etc. pipes arrived today. I will get her fired up tonight as long as the wife lets me lol.. 75 hp will be more than enough power Quote
Gumball12 Posted May 8, 2015 Author Report Posted May 8, 2015 Wow it sounds good! I am at 50 piolets and idles best 1 turn out or less...guess 52? Or should I wait til I do a few cycles? Quote
RadarRacing Posted May 9, 2015 Report Posted May 9, 2015 I would wait on it but yes you could do a 52 or if it tunes fine 1 turn out there is no reason whatsoever to swap pilots. I usually only go bigger pilot if it wont tune enough. Even almost closed is fine, yet the guideline is 1.5 to 2.5 turns. Do timing around +5 or Quote
sleeper06 Posted May 9, 2015 Report Posted May 9, 2015 1 turn wouldn't bother me at all ,as radar said I've run em almost closed Quote
Gumball12 Posted May 9, 2015 Author Report Posted May 9, 2015 162 is too lean. After short open run, plugs are evenly whit/grey. Bike did not get too hot though at least according to my lazer temp gauge. Try bigger jets soon. 170 then down Quote
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