Safe to run a 155 main?

[weaselcircus]

I finally got around to re-jetting my 2000 KDX200. I bought it brand new and it has never been re-jetted before. From what I could find, it seemed that the stock main jet was supposed to be a 160, and the recommended size to go to was a 155 (from searching the posts on here and the justkdx tech tips). But when I pulled out the main, I found it was actually a 175, and not a 160 like I was expecting. So my question is this: Would I still be okay to drop to the 155? Or do I need to start up higher and work my way down? The bike is stock except for the snorkel has been pulled and a few holes drilled in the air box lid. Riding area is Idaho with elevations something like 3000-5000 feet. Thanks!

 

[D36-108A]

Holy #$%!, that bike must've run like $#!&! even at sea level. At your altitude, you probably will even end up smaller than 155.

I hope it didn't have a 175 in it to compensate for an air leak or something.

 

[JasonWho]

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[clutchcover]

I'm from Pocatello, and I run a 155. The 175 is way to rich even for a winter jet on my bike. I ran a 162 in 10 degree weather and it checked out alright. Have you been throwing oil or fouling plugs alot? I am not sure what the correct jet for your bike is as every bike runs different. Where in Merridian do you ride? Ever make it this way? It's rare to find another kdxer in Idaho.

 

[weaselcircus]

Okay, thanks for the info. I'll give the 155 a test and see how the plugs look. It was definitely smoking and spooging quite a bit. Would foul a plug about every 3rd ride or so. But this is my first 2 stroke (and 2nd bike ever) so I didn't have anything to compare it with and didn't realize that it might be so poorly jetted.

As for where I ride around Meridian, I usually head up into the foothills around the valley, out to the Danskin Mtns, or down to the Owyhees when it's early spring or late fall. I actually grew up in Pocatello, but didn't have a bike when I was there. I still have friends and some family there, so I make it back occassionally for a visit and usually sneak in some fishing or bird hunting.

 

[mudwalker]

You should clean and repack your silencer also.

 

[John Harris]

What size pilot jet is in it? I am confident you could run a 45 and maybe even a 42. Your bike should go years without fouling a plug. IMO at your altitude you could probably run a 150 main. Do the changes correctly!

 

[Jim Crenca]

Jetting info is only meant as guide as each bike reacts differently.
Assuming there are no air leaks & bike is in good condition, WOT plug chop is the ONLY way to evaluate main jet (IMO). My 94 is lean with anything smaller than a 162, and I run a 165 for a margin of safety (don't have time to rejet for elevation, air density, barometric pressure, etc).
Also consider that the level of expertise from an internet based forum will very greatly.

 

[JasonWho]

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[clutchcover]

Stock is 160 on the 200's. Still a long ways away from factory baseline.