okay...cant.....take......it ......anymore.......must.....get....the.....351... ..kit....
Did the DJ kit with KN filter, screen removed and alternate snorkel yesterday. much snappier response and the wheel actually come up off the ground with my fat a$$ slightly now :P. only gave me a taste to go up from there. as far as stock exhaust go (trying to keep it quiet) and the stock carb with 300 DJ kit, do you guys think this will work okay? 128 needle near sea level. much better than the stock on my 07. I really dont want to have to abandon the carb or the exhaust at this point. Seems like reviews are okay w/o the change. thoughts?

 

oh forgot, I did get the 13t sprocket but hesitant also to put it on for the same reason bailor. actaully fairly happy with the stock gear ratios, just want more kick in the ****....

 

Don't get me wrong matty, I appreciate what the 13t did for me. There's times that it helps quite a bit. It lets you maneuver around at idle without having to pull the clutch, and also helps when using the gearing to keep yourself slow going down a steep hill on the trail. For what you gain on the low end with it, you really don't loose that much on the top to compensate. But that's just me. I do mostly tight, technical trails (which it's GREAT to have) and the like--probably 95% offroad, 5% street. There's a TON of combinations out there, you just have to figure out what will work best for you according to your riding style. But if you ride mostly trails, don't hesitate to give it a shot. It's not permanent--if you don't like it....just put the 14t back on. Just give it a shot, I think you'll like!

I can't give you any advice on the stock carb with the 351. I put on a Mikuni TM36-68 pumper when I did the 351 so I don't know any different. It seems like guys have been using it with a decent amount of sucess though. However, that stock exhaust is the biggest restrictor of power on your bike...get rid of that piece of crap! If you keep it, and now you add 100cc to that same choked out exhaust? Iccck! I can't comment on how it runs with a 351/stock exhaust setup 'cause I never did it, but man, I gotta think it wouldn't be good. Again, there's a TON of setups when it comes to exhausts, and I understand if $$ is a limiting factor, but it's something that can make a huge difference on this bike. See--once you start the mods, it's hard to stop--one slippery, expensive slope!!

 

Keep the stock carb.. you wont see any huge diference in changing the carb vs using the dyno jet kit. However, dump that stock exhaust like a bad habit and never look back at it again!

Honestly,

I think it would be pointless to spend 500.00 on the 351 kit, 70.00 on the dyno jet kit and then use the stock exhaust..

I had the big gun, it was one of the loudest.. I liked it, it did not bother me once I had my helmet on, it was not that loud. There are other exhaust systems that are not as loud that will help wake that bike up!

If neither of those work for you then go get a stock exhaust off a klx300 at the very least.

 

351 runs well with stock carb. I have no complaints.

 

I am thinking of getting the 351 kit for my 250SF motard... what jetting are you using in yours with the stock carb?

 

stock pilot, DJ 132 main, DJ needle, 1.5-2.5 turns out on fuel screw.
Could probably go down one more on the mail jet but untill I can get to a dyno with A/F sniffer I'm going to keep it safe.

 

And what approx altitude are you at CousinLarry? When you say go down one more on the main jet, I assume that you are talking about going down in diameter/size to lean it a little more...

The stock bore of the stock carb will flow a sufficient amount of air? No need to get the larger bore style that Bill Blue sells for use with the 351?

 

For trail riding, both a bigger bore kit and a pumper carb are totally worth it. I went the Bill Blue 331 a couple of years ago and it gave the motor the ***** it needed to climb hills and powerslide corners. The pumper carb then gave the motor a more instant throttle response which is necessary to lift the front over obstacles. Yes, both are completely worth it. Though you will need a better flowing exhaust and ditch the airbox lid to round it out.

Then you'll find you're going so much faster, you'll pretty much have to deal with the suspension next

The upgrade in power is very easy to modulate. In no way has it made it more difficult to ride the bike.

 

I'm not sure which pictures you've been looking at. Here's a side by side 250 and 351. Do you think those channels are almost gone?



The bike works fine with the 351, stock carb and stock muffler. I rode mine thousands of miles in that configuration, and it only had the stock muffler relieved with a 1/2" drill bit, and rejetting in the stock carb. And the KDX200 snorkle.

It ran fine. If you rev'd it to only 4,000 rpm and dumped the clutch, it would stand straight up. And that was while using the bigger 15T countershaft sprocket.
If you go to Bill's website, you can compare the 351 dyno runs with the stock carb and pipe and then the 351 with the pumper carb with an aftermarket pipe.