I thought I would shoot a quick video on my phone so you can see how rough it idles, the "misses", how it responds to a blip of the throttle, etc. Any suggestions of what my problem might be? I gave the carb float bowl a few solid taps with the butt of a screw driver in case the float was a little stuck - it shouldn't be though as I stripped and gave the carb a thorough clean before fitting it - and I didn't change the float height when I did that as it had worked perfectly fine before.

https://www.youtube.com/watch?v=NzXp...ature=youtu.be

 

What happens if you shut the petcock off for a few seconds with the air mix screw all the way in? How's the plug look?

Bike sounds terrible doesn't it? A weird throaty sound, but part of that could me your cell phone microphone..almost like the slide is sticking. You probably didn't have the carb apart during the 351 install though did you?

 

Not a happy motor. Is the valve timing correct?
I always start a diagnosis with the basics.....and what I fiddled with last is first on my list.
Had the engine run with this carb..after your thorough cleaning? Or was the carb done at the same time as the other work?

 

Arctra,
I read a protocol for tuning the pilot jet on our CVK. Turn in pilot all the way so the bike still barely idles. If it dies, increase the idle speed a little until it does. Then open the pilot jet 1/8 to 1/4 turn at a time to find the highest idle speed. Your pilot sounds rich and acts just like mine did after doing the 351 and jetting 38 & 128 (or 132, don't remember). Adjusting the pilot made very little noticeable difference and adjusting the 35 certainly did. But I'm at 2,700 ft. I figured the pilot and main were both rich and ran rich for the break in then leaned it out.

 

Thanks - I'll try that. Sounds odd to turn the screw all the way in - if I hadn't already done that with the engine still running I wouldn't have believed it would be possible.

 

Try putting the airbox lid back on. The lid off, backfire mesh removed and twin air flow way more air. I have a similar setup and even with the 132 jet it does not like snorkels removed. Runs like crap with the lid off.

 

Woo-hoo! She runs! I have finally got the KLX running on the 351 big bore after several problems getting the jetting right. I have just done a test ride with the Dynojet #132 and the Dynojet needle dropped to the clip on the 2nd groove. Bike pulled nicely from idle to 8000rpm without any sign of rough running.

I think I will try taking her out for a test ride in the bush this weekend. Feeling excited to have her running again!

 

When I did a test ride in the bush with my fuel needle on the 2nd clip from the top I started struggling around the 6000 to 8000rpm range with the bike running rough once up to running temp. SO I moved the clip up to the top groove on the fuel needle to see if that helped. Well it didn't just help, it made the bike sing! I did a full days ride yesterday with a mix of tight single track and open fire trails, and the bike ran flawlessly the whole day. So I am VERY happy with the upgrade now

So this is the setup I have landed on:

 

Arctra,

Congrats on nailing your suspension and jetting.
Would you like to share your settings here.
https://docs.google.com/spreadsheet/...FE&usp=sharing

 

Done mate. Good idea.