Highbeam - you have the DJ 116 in? Where are you with exhaust and airbox? Stock or modified. Just wondering. My carbs setting on the bench right now, raising the clip from 3rd to 2nd position and thinking about dropping another size on the main jet.

My riding buddy has his KLX300 carb on the same bench. It had already been worked over by the dealer shop in town (and this one in fact is known for doing good work and knowing what they are doing), and they had changed the pilot from 35 to 32 and did some other work. It was interesting to see the "pros" actually dropping the pilot size. Tell you what though...his bike takes a while to warm up before it goes. Without the choke on for a long time, it just dies.

 

You hit upon something that I believe a lot of people overlook. I am no pro, but even a blind hog can find the proverbial acorn occasionally. Over many years of putzing with engines, and especially single cylinder 4-strokes, I think overall performance and fuel mileage is much improved by jetting at the leanest and cleanest edge possible. This can be a fine line, but IMO it's worth finding. If your bike takes just a little longer to warm up, what's the problem? Otherwise you may ride a bike all day long that is a bit rich and not yield as crisp a throttle response or good fuel mileage. And personally I think an overly rich CV carb is the worst, as it is really slow to react when jetting is not spot-on.

When installing my 300 cylinder, I did a 35 pilot at the same time, but it was quite evident that the OEM 32 was spot-on for good idle and off-idle response. I'm always amused to see someone claim how well their bike starts once they "richened" up the pilot jet. I don't doubt that a bit, but there's a price to pay later when the engine is warm...and that's a whole lot longer than the short warmup period. Drilling the lean starter jet is the proper fix for that, and then select your pilot jet for optimum performance for a warm engine.

 

TNC:
You say "OEM 32." Our bikes come stock with the 35, correct? And you used the 32 with better results? My buddy has another 32. He was going to put it in and then found that work had already been done. And, the enrichment was already at 0.018" too (maybe Kaw already had it right on the carb for the 300?). Now you got me thinking of putting in that 32 while I got this thing apart. I can turn off the choke after only 10 to 15 seconds even when chilly and 1.5 turns out on the screw. Sounds rich.

 

Nope...misquote on my part. I did mention the blind hog, didn't I?...LOL! No, I went from the stock 35 to a 38, but even with the bigger bore I went back to the OEM 35. Sorry for the confusion on the numbers, but the point remaining the same...the leanest jetting without being too lean is probably best overall. Not sure how the 32 would work out, but with a bigger bore, I'd be more concerned about its off-idle throttle response than the idle. Still, one wouldn't know without trying it to be positive. I've just been impressed how my bike runs in my home area at about 1700' and then how well it runs even at altitude in CO and UT. I figure I must be close enough to ideal to leave it alone...LOL!

 

So....what are your thoughts then? Should I throw the 32 in and see how it runs? I don't see anyone else here trying it. But he's got one on the 300...
Feeling like a blind hog.

 

Try any thing you like and tell us how it works. We all have different tastes and expectations. Some want power at any price. Some want to do what everybody else does.

I believe in tuning for the major part of when you run the bike. It all depends.

Where I lived a year ago it was a mile to the first stop sign. Choke the bike, start it, out the drive way, push the choke in forget about it.

Where I live now the stop sign is 20 ft from the end of the drive way then another one shortly after. It needs to be tuned different.

Don't tune your bike for 5% of the riding. Tune it for what works for YOU. Now I am running a 351 and getting 60+ mpg. It has a flat spot when cold just off Idle, but I may live with it for the fuel mileage. The flat spot goes away once its warmed up. Temp here is still in the 30s and 40s F so I need to wait till its warmer before I do any more or I will be tuning the bike for spring not summer.

I marked my throttle for 1/4 and 3/4. Almost all of the riding I do is at or below 1/4 turn on the throttle. Even at 65 mph. SO the main jet will not affect my commuting much, only when I really get on it.

I WAS running a 128 main with the stock carb and cylinder. I thought it worked quite well. Everybody has their own expectations.

David

 

Yes, I followed the directions on the main jet. With my stock intake and exhaust that means a 116DJ jet.

Now on the pilot jet I left in the OEM 35 but only turned the fuel screw to 2.25 instead of the 3 turns that the directions state. I like high mpg and want to try and eek out a little more this way. I have no apparent lean symptoms.

Oh and of course I drilled the choke jet to 0.018".

All of the above makes the bike start like it should and run right.

 

This might be the setup I'm going for since mine is stock. Also, this should fix the "surge" that is apparent when cruising 1/2 throttle at 70mph.

 

I have been in my carb at least 10 times in the past 2 weeks experimenting with different jet, spring, and needle combinations.
To fix your 1/2 throttle surge, you can install the DJ needle and spring without removing the carb.
Remove the seat and tank plastic. Remove the 3 tank mounting bolts. Slightly lift the tank and tilt it to the left. (no need to disconnect hoses)
With a stubby philips, you can now get into the top of the carb to replace those parts.
If the only reason you are going into the bottom of the carb is to install the DJ 116 main, I would not bother, as I found it to be equivalent to the stock 118.
On the other hand, if you are going to drill the starter jet, you may as well remove the carb and do the work on a bench.
Craig

 

Thank you for the insight craig. That seems to be the only problem I have for this bike and since the DJ kit does accommodate for future performance upgrades (exhaust), tinkering with just the needle and spring is a relief. By the way, what performance do you get out of the bike by drilling the starter jet? And one more question, forgive me, what kind of modification would you suggest for my bike? Riding style would be mostly highways and passing vehicles and also this summer I would be riding to CO.

Thanks in advance!