351 with stock carb - a detailed review

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  #121  
Old 05-31-2017, 10:50 AM
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Originally Posted by fixer53
just ordered my bb 351 kit, now I need to order some carb jets. I already have a dynojet mq2152 kit, but the biggest main jet is a dj132. after reading this thread,(and thank you for all the info) I would like to start off with a dj146 , a 38 pilot and a dn0228 needle 1n with stock spring. the question I have is where to get the jets from? jets r us have the main jets, but I am lost on witch pilot jet to order, ANY advice would on this kit install would be appreciated.
Pilot jet Keihin N424-25B. I use jets r us.
 
  #122  
Old 05-31-2017, 02:52 PM
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I just got a 38 pilot from JetsrUs, S10gto is right on the part#. I would personally skip the 38 and get a 40. I have a 38 and it is still decel popping pretty bad even at 3 turns out. 146 is probably a good start, 144/1N also runs great with no issues to report, I would get 140-150 sizes and you'll be covered for whatever we figure out.
 
  #123  
Old 06-05-2017, 02:26 AM
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got my 351 kit, engine taken apart, will start install tomorrow(cant find my gasket seal... oops . gotta wait till I go advance auto to buy some, to late tonight , but will get a fresh start in the am). I am curious though about the new piston with the bill blue kit, the cinder bore is 3.51 and the piston is 3.366 that seems like quite a difference. the other question I have is the ring gap positions, the JTpiston installation guide has the gaps at90 and 270 degs and the Kawasaki manual has them at 0 and 180 degs (0degs=front of bike and 180=back) any suggestions on which guide I should follow.
 
  #124  
Old 06-05-2017, 02:38 AM
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I just put the ring gaps on opposite sides when I installed my 331 piston. The rings will move while the engine is running anyway so I didn't worry too much about it (thats why 2 strokes have the rings pinned in place).
 
  #125  
Old 06-08-2017, 12:20 AM
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Hey Bryan.. I know you've got a lot "going on" but I wanted to encourage you to not reinstall the stock needle before dyno testing. The stock needle is so much "thicker" in it's entirety - and longer in length - that it could seriously "taint" the fueling curve all the way to redline.. It may be that, after analysis, the stock needle is exactly what is needed - but it is premature to resinstall it at this point.
 
  #126  
Old 06-08-2017, 12:27 AM
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I'm committed to this setup to get the dyno testing done. Now we just need a day without rain storms. I still need to get the new springs installed. After that, I'm ready to get it tested.
 
  #127  
Old 06-08-2017, 05:30 PM
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I have changed to a 40 pilot, highest idle is at exactly 1 turn out.

Was previously running a 38 at 2.75 turns out hmm.... Also interesting is that the 40 pilot seems to have cured my warm up cold nature issues of wanting to lean out and bog within the 1st min or two or riding. With the 38 I had to be very slow with the throttle during warm up or it would lean bog and die, havnt ridden it much but that no longer happens...good throttle response almost as soon as it starts.

Oh i also changed to a 146 and kuoba screw vs stock screw so maybe thats affecting it... I changed 3 things at once just to make KLXster's life difficult lol, just kidding man
 
  #128  
Old 06-08-2017, 06:21 PM
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It really seems that anyone below 2k ASL ought to be using the #40 pilot jet..

Jabara, with the Kouba and #40, you can fully control idle, decel, and "below 1/8th" throttle ops.

The "standard setting" to start with - the setting to have before any fine tuning - needs to be midway between idle drops. When warm and idling @1300, turn in till lean idle drop, then out to rich idle drop, then back in to the midway point between the two..

P.S. Do you think th Kouba has the exact same taper and length as the stock fuel screw?
 

Last edited by Klxster; 06-08-2017 at 06:24 PM.
  #129  
Old 06-08-2017, 06:59 PM
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Originally Posted by Klxster
It really seems that anyone below 2k ASL ought to be using the #40 pilot jet..

Jabara, with the Kouba and #40, you can fully control idle, decel, and "below 1/8th" throttle ops.

The "standard setting" to start with - the setting to have before any fine tuning - needs to be midway between idle drops. When warm and idling @1300, turn in till lean idle drop, then out to rich idle drop, then back in to the midway point between the two..

P.S. Do you think th Kouba has the exact same taper and length as the stock fuel screw?
Midway between idle drops also happened to be my highest idle point @ 1 turn out.

Well my good sir... as far as the taper you are in luck, I took a photo of them side by side and they are slightly different, the Kuoba having more of a triangle shallower taper and possibly a finer point, to my eye anyway. Pic attached.
 
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  #130  
Old 06-09-2017, 01:21 AM
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I thot the Kouba was different from stock.. Explains why you are "good" at 1 out vs more like 2 out for the stock fuel screw..

Carry on my good man - God save the Queen, the British are coming, bring out yer dead..
 


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