Wow, Ron...I'm impressed that you get by with a 120 main. I have a 128, and it seems right at that edge of perfect where fuel economy is optimum without fear of burning a hole in the piston...no pinging. You run an aftermarket pipe, don't you? What intake mods do you have?

Just thimking out loud here.

 

TNC: your 128 is a dynojet, isn't it? Which based on the jet comparison chart is equivalent to a 137.5 Kehein.

Ron: is your 120 a Kehein or other?

Conversion Chart: https://www.kawasakiforums.com/forum...e2/#post442610

Just thimking too much.

 

Ahhh...I didn't see that. I just assumed DJ...and you know what they say about that.

Additionally, I don't why some of you guys run OEM style jets. Everyone knows the DJ jets are much faster...add about 3hp from what I've seen...LOL!

 

horse power gain is the square of the orifice internal diameter times the root of the last number you thought of minus (3.145 times the number of the post in the thread you are reading.)

 

It's getting too deep for the knee highs, time to dig out the hipwaders.

 

I took all that down, redpillar.

I believe the reason I can use a 120 main is that I also am using the KLX300 emulsion tube instead of the 250 tube. Kawasaki calls it a needle jet holder. The difference is that the 300 tube has additional air bleed holes. That provides better fuel atomization with the big bore. Since it atomizes better, the burn is more efficient and less gas is needed. With poorer atomization, it takes a larger jet to get enough gas into the cylinder for a reasonable burn. The less atomized mixture isn't as efficient.

My jets are all Keihin.

I'm using a KLX300 pipe and muffler with a custom 1 1/4" tip. The carb has the 300 emulsion tube as mentioned. I'm also using the 300 slide. The difference with that slide is that is has an additional diaphragm chamber bleed hole.

Oh, and I know this is sacrilegious, but I am using the oem snorkel.

Ron

 

Now hold on there, Ron...LOL! Where did you get this info about that difference in the carbs between the 250 and 300? I guess I'd never heard about this. I know what you're referring to on the emulsion tube deal and the slide deal as far as it possibly being beneficial, but it's the first I'd ever heard of it.

 

TNC:
You're too busy putting miles on your bike and not sitting around reading posts. I picked up the emulsion tube and installed it for the 351 project.

 

When I modified the carb as a result of the 351, I wanted to use all oem parts. I compared the differences between the 250 and 300 carbs. Basically, other than jets, the only differences were the slide and emulsion tube.

My guess was that the emulsion tube had more (or differently placed or sized) air bleed holes. That turned out to be the case. I had no idea what was different with the slide, but I bought one to find out. The difference was that the slide is metal and has the extra bleed hole in the side.

I doubt if the slide makes a lot of difference, but I am using it anyway. I can affirm that the emulsion tube makes a big difference (in my case).

More on the slides. You can skip this.
It's my opinion that the slides don't necessarily need to rise faster than originally designed. If the slide rises too fast then the intake charge is leaned out until the carb can catch up. To counteract this, people usually raise needles and increase main jet sizes. Of course, that just masks the problem and creates additional problems of excessive richness after the slide is stabilized. Most don't notice this because a moderately rich condition is difficult to "feel".

Also, too large a hole can cause the slide to flutter. That causes all kinds of jetting mayhem.

I think the 300 slide has the addition bleed hole because the slide is heavier than the 250 slide and without it would rise to slowly.

Ron

 

Great info there, Ron.