421 Serval plug Chop. Opinions.

[2004LEBanshee]

421 F.A.S.T. ported serval, PWK 35's, Nology coil wires. +4, K&N pods, VF3 Reeds

This thing was running crappy (sputtering up top and sometimes down low) until I dropped the main from a 155 to a 152, 45 Pilot, 2.5 turns out. CEL middle clip.

Runs pretty good now just seems like this is pretty lean compared to others on this site. My only problem now is I think the pilot is a little big some how. When it starts cold I dont need to hit the throttle but when warm I need to hit the throttle to get it to start. I also did a plug chop with 155 and the chop looks the same but the bike does not rev near as clean. Is it possible it just likes a leaner pilot then most or are a lot of people on here off with there jetting. Opinions.

 

Edited August 24, 2012 by 2004LEBanshee

[locogato11283]

I just won the 0-450cc class at the National Hillclimb on a FAST 421 Serval. Rocket pipes, 35PWK, pods and +4 timing. 160 mains and 48 pilots.

[RadarRacing]

Sounds about right but I bet you are slightly rich on the needle. Just remember to check the main again if you move a clip or two. If I had to guess its needle position.

[RadarRacing]

Having to hit the throttle to start when warm is usually because it is rich on the low circuit. You may need a smaller pilot as well as check the needle. I do half throttle chops but I like to keep it a little fatter on the needle than what your mainjet chop looks like. I would bet it is pretty fat with the cel needle in the middle especially if you have a midrange pipe.

[2004LEBanshee]

Sorry forgot to include I'm running shearer inframes. Seem to low on the main but I think the chop looks good and it runs like crap with a higher jet. I might. Try one smaller pilot and bump the main up.

[SuperMex]

Whats your elevation?

[2004LEBanshee]

1000 ft

[locogato11283]

Something isn't right. You shouldn't be that far off in jetting. Our elevations are the same and mine starts, idles and runs perfectly.

[guns4children]

I'm running 48p 160m cel 1 clip up. + 6 timing.

[Rustynail]

I'm running 48p 160m cel 1 clip up. + 6 timing.

 

But your doing 3/4 throttle plug chops

[2004LEBanshee]

I could never run those jets. I don't know what could be wrong. Oem cdi oem stator all check fine had an oem coil a few weeks ago and same thing

[dozer]

on my 421 serval im running 35 pwks 160 mains 48 pilots cel needle in the middle clip. i also have the nology coil and wires with shearer inframes. very easy to start on the first kick, hot or cold.

[2004LEBanshee]

My previous motor was a stock cylinder FAST 4 mill play port. It seemed to run smaller jets then everyone elses as well. Mine ran real strong so I just figured there was nothing wrong 5 years no problems. For this build I put a new OEM Stator and an unlightened oem flywheel on but the carbs CDI and wire harness are the same. Its a differnt motor but still likes way leaner jets then anyone elses . To me the plug chop seems to look good. Im not sure if this is something I should keep chasing or its just the way mine is. Is is possible something is wrong with the carbs and they flow diffently? I purchased them new off FAST when I built the 4 mil stocker about 6 years ago.

[2004LEBanshee]

I started today at 158 and a 48 and it was real boggy at all RPMS. It got better as I went down. Did the plug chop when I got to something that ran good.

[2004LEBanshee]

Would a bad flywheel have symptoms that go away with leaner jetting?