Serval Jetting

[robert.b.west]

I just got the motor together and am going to start working with the jetting. I am kind of looking for a starting position. The carbs are 33mm pwks with clamp on k&n's. The pipes are t-5's (Not what I want and will change soon enough) Elevation is ~800 ft. I was told the main would probably end up around a 155 but that does not make sense to me because that is what I was at with my ported stock stroke. Does around a 155 make sense? And where should I start with the pilot? I think i have a 48 in there from before.

[Snopczynski]

I just got the motor together and am going to start working with the jetting. I am kind of looking for a starting position. The carbs are 33mm pwks with clamp on k&n's. The pipes are t-5's (Not what I want and will change soon enough) Elevation is ~800 ft. I was told the main would probably end up around a 155 but that does not make sense to me because that is what I was at with my ported stock stroke. Does around a 155 make sense? And where should I start with the pilot? I think i have a 48 in there from before.

if it helps we were running a mikuni tm28mm flat on a 4mill with a clean up port at a 370-380 main, with a serval 4mm it wanted 460 main jets in it.

[Judge1]

I just got the motor together and am going to start working with the jetting. I am kind of looking for a starting position. The carbs are 33mm pwks with clamp on k&n's. The pipes are t-5's (Not what I want and will change soon enough) Elevation is ~800 ft. I was told the main would probably end up around a 155 but that does not make sense to me because that is what I was at with my ported stock stroke. Does around a 155 make sense? And where should I start with the pilot? I think i have a 48 in there from before.

 

 

I have similar set up and the 33 pwks are running at the same range now, stroked and ported, as they were on stock port and stroke. With the exception of the needle change(cel I think) narrower tapper. I am going to 155 mains now that it is warming up. Went up one size for winter and now that it is starting to bog its time to go down to 155 again. I have 48 pilots and needle is middle clip, air screws 2 turns out.

[robert.b.west]

I think I will start around a 160-165. And go from there. I will post what it ends up being.

[RadarRacing]

PWKs many times use the same mainjet range on many different motors 350s,397s,421s etc. I think you will find the serval is a motor that will want a little smaller mainjet size than normal as it has a low exhaust port and higher transfers. It wouldnt surprise me if you ended up in the 140-145 mainjet range with 33mm PWKs and CEL needles.

 

Judge if your bike is bogging with that jetting as it is warming up you are probably quite rich at a 155 main. A serval is going to be a fairly hard motor to get to bog.

[No Limit Powersports]

Robert start with a 160 main cel needle and and the stock pilot and you will be real close.

[robert.b.west]

Yup. That is what I have in there now but wont be able to check til the weekend.

[gotta_goatsfast]

Start with 162 main, 50 pilot, CEL needle middle clip and break it in. Then plug chop your way to the perfect jetting (my guess is 155-160 main and 48 pilot). My serval with 35s seems to really enjoy 158s... I could probably go a little lower but I like it to be slightly fat for reliability and such.

[J.J.]

Yup. That is what I have in there now but wont be able to check til the weekend.

 

Robert, please follow up with your results once finalized, I will also be running 33PWK's on a 68x58 Serval, (pipes undecided) and value your feedback.

 

Many thanks!

J.J.