Put the slide diaphragm in some hot water - expands it a bit as well as softening it up due to warm temp. Dry and install. That was one of the tips when doing the KLX300 jetting my brother tipped me off to - put the slide diaphragm down into a cup of hot water while doing the work.

One other tip, when you do valves if you have to wait to get shims or the like put the cam cap back on and snug the bolts - keeps the gasket in shape. Don't let it sit around and shrink up or whatever.

 

Well, finally got it all back together and the "new" engine with the rebuilt carb is running. It fired right up yesterday and I took it around the block. Yesterday it fired up right away. This morning I needed the choke to get it started. But it was cool by So Cal standards at 48deg and my past engine usually needed the choke.

But now I have more questions. I will probably start a new thread because this is more about advice on the "new" engine break-in. But some is still carb related. I am specifically interested in advice on checking whether I am running lean or rich as lots of folks discuss on here. What are the signs that I have either situation? Or, how do I know when I have it in Goldilocks mode, "just right"?

Note I am Los Angeles at basically sea level and everything in the carb is stock. I did purchase a rebuild kit that had a new needle, gasket, pilot air screw, etc. Since I had trouble w/ the pilot air screw. Since I had the issue removing the old pilot screw, I didn't have a reference position. So, I used the service manual setting of 1 and 5/8 turns out.

Thanks to everyone for chiming in on this thread. It has been about 18mo since the engine originally seized and I haven't been on a bike since. Yesterday was awesome just to get around the block. Really excited to finalize things and start riding it again.

 

With the engine warmed up, adjust the pilot screw for max rpm. You may have to go back and forth with the idle speed screw to get optimum setting. That will take care of the idle mixture adjustment.

Ride on
Brewster

 

Well ok Jeff.. So the carb is carbing correctly at all RPM ranges..? If so, then you can move on to next level CVK tuning..

Rich or Lean.. We will need to know the current state of mods/tune your bike is running..
Create a signature with your bikes' current "status" - start by clicking "UserCP" in the upper left of your screen when your logged on.. See my signature below..

 

Brewster - Need to get a pilot screw adjustment tool. Or, I will need to spring for one of the 3rd party pilot screws that allows finger adjustments. I will also check w/ some friends to see if anyone has the 90-deg adjustment tool.

Klxster - So far only the most basic ride around the block, but seemed to be "carbing" OK. The engine idled at about 1500 rpms and sounded clean. Probably only shifted through 3rd maybe 4th gear on the short ride and never got above 40ish. No noticeable popping in the exhaust on decel. There was always a little delay in going to WOT as the carb got going, but I think that is normal for the stock CVK from what I read. Can you define the rpm ranges I should be checking? Also, what should I check for, just smooth engine operation?

The bike is stock everything (except for the used replacement engine, but that is all stock). I updated my signature to indicate the date of original engine death and the recent replacement and carb rebuild.

Thanks again to everyone for chiming in w/ assistance.

 

Alrite! Yep, check for smooth operation in all situations - certainly including full throttle snap-and-holds from a reasonable starting RPM (3.5k) up to at least 9K rpm.. If all is well then you have a good basline for starting your performance mods - if that is what you want to do.. Cheapest first mod would be a DJ2152 carb kit, installed as per instructions for stage 1. This mod will address your concerns about the bike running soo lean in stock configuration.