351 with stock carb - a detailed review
#21
I think its because these cv carbs are very forgiving. You can compensate for a shortage in one circuit by adjusting another. I want to get the most out of this kit so I'm going big on the jets. I also think that a lot of people with the kit are running a stock header and/or a lid. I have my bike opened wide. If I don't feel all of this helps, ill back down the jetting a little bit. As for the stock 35 pilot; if the exhaust turns red at idle, it's way way too lean. That's beyond an adjustment of a screw.
#24
#25
I just think its really interesting that if you look at "the spreadsheet", most people with 331 or 351 kits are running 128 or 132 main jets with either stock 35 or 38 pilots...
I realize klxster has more dyno time than probably that whole spreadsheets worth of people, but i do think its interesting that so many people run 128 or 132 and seemingly work ok. Klxter i sure wish you had a big bore kit to dyno...
I think i'm going to get a wideband AF meter when my kit gets here
I realize klxster has more dyno time than probably that whole spreadsheets worth of people, but i do think its interesting that so many people run 128 or 132 and seemingly work ok. Klxter i sure wish you had a big bore kit to dyno...
I think i'm going to get a wideband AF meter when my kit gets here
The spreadsheet serves a good purpose. It will give guidance to those that need a "good working" setup - and my dyno testing proves that "good working" setups include main jets as small as DJ132's.. Bryan is correct that the performance needles and lower clip positions can create a "good running" KLX with a main jet that is way too small - but top end power(perhaps even engine health), is greatly reduced
I do not want a "good working" setup - I want the most HP and TRQ I can possibly get from my bike - and I found the setup that does that.(With what we currently have to work with in the way of needle choices..)
It just so happens that what I found is waay off from all the "good working" hand-me-down setups that have been used for years now.. And, in a way, that's too bad. But, in another way, that's really good as everyone running a setup "from the herd" can now find biggy power with minimal alterations, if they want to run lidless..
You choose dyno data (mine/Houstons4/etc) or dogma (the spreadsheet).. Dyno butts and plug chops, as it turns out, will cost you the HP and TRQ you've paid good money for..
Any 250 running a DJ128 or DJ132 had certainly better also be running the lid on the airbox. I don't have data for 351's. No one does. But feeding it the same as you'd feed a 250 has never made any sense to me..
Last edited by Klxster; 04-17-2017 at 08:46 PM.
#26
I got to take the bike out for a short ride with my carb's initial setup. It has the #40 pilot, DJ needle from the 2152 kit on the 3rd notch, slide drilled (can't undo that), DJ 140 main jet, screw out 2 turns. Riding near sea level with my open setup. So this thing rips. It has absolutely no hesitation out of the hole and pulls hard right up to where I let off for break in purposes. The only thing I noticed is that after my ride my idle climbed to 2200 rpm. I'm guessing that's because the rings are seating in and causing less friction. I'll just adjust the idle screw for now. With the bike running this well, I'm going to keep it this way until the 100 mile break-in is done. After that, ill get to play with the top end performance more. I'll make updates as I experiment and I'll also update my first post with my setups and how they perform for quicker reference. I also noticed that the extra power really did a good job of showcasing the lackluster suspension. Especially the forks. Ill have to try to dial them in better.
#27
Haha. I got auto corrected. Jets R Us mikuni, keihin, hitachi, holley, jets and carb parts
KEIHIN SLOW JET N424-25B
#28
Dont get me wrong I know you have the setup nailed, i was just pointing out the craziness of how different the setups were. My butt/ear dyno agrees with you, I think the DJ 2152 stg 2 128 MJ, on 3N with the light spring gives me a overly fat midrange when i get on the throttle and probably is on the leaner side of safe at WOT. Definitely going to order some 140+ jets and experiment with 2N... closer to what you are doing
#29
I got to take the bike out for a short ride with my carb's initial setup. It has the #40 pilot, DJ needle from the 2152 kit on the 3rd notch, slide drilled (can't undo that), DJ 140 main jet, screw out 2 turns. Riding near sea level with my open setup. So this thing rips. It has absolutely no hesitation out of the hole and pulls hard right up to where I let off for break in purposes. The only thing I noticed is that after my ride my idle climbed to 2200 rpm. I'm guessing that's because the rings are seating in and causing less friction. I'll just adjust the idle screw for now. With the bike running this well, I'm going to keep it this way until the 100 mile break-in is done. After that, ill get to play with the top end performance more. I'll make updates as I experiment and I'll also update my first post with my setups and how they perform for quicker reference. I also noticed that the extra power really did a good job of showcasing the lackluster suspension. Especially the forks. Ill have to try to dial them in better.
Have to say it is hard not to really get on the throttle during break-in. As you said, I can really feel the added power even when only going part throttle. Response is great!