KX Riders

Maintenance & Technical => KX500 Original => Topic started by: Toom038 on May 28, 2013, 09:08:58 AM

Title: pressure/vacuum test?
Post by: Toom038 on May 28, 2013, 09:08:58 AM
Does anyone know what pressure and/or vacuum I should use to test a 500 motor? I have a '99 that I can't get jetted right. I want to eliminate all other issues before I go postal on this carb and put a new one on it. I'm at a 180 main, 52 pilot and stock needle at 4th clip from top and it still blubbers off the bottom. Floats are set at 16mm and I put a rebuild kit in the carb. Seems fat on the bottom and then hits hard at upper mid. I'm right at sea level, running 50/1 93 pump gas. Is there something else I could be missing? Thanks in advance.
Title: Re: pressure/vacuum test?
Post by: sandblaster on May 28, 2013, 11:44:23 AM
Should hold 7lb positive and negative pressure overnight.
Thank Yodarad for the info :-)
Title: Re: pressure/vacuum test?
Post by: joko on June 30, 2013, 11:09:43 AM
 I tried a 2" expansion plug in the exhaust port to seal it. It was a little too small by about .080", so I wrapped electrical tape around the rubber OD and put it in. It still leaked, when I checked it with soapy water, I think the grooves in the exhaust port from the pipe contributed to the leaking, but couldn't get it to seal after many attempts. Anyone have a better plug solution?
Title: Re: pressure/vacuum test?
Post by: Gage on July 01, 2013, 03:45:49 PM
wait I know this one  :-D http://www.kxriders.com/forums/index.php/topic,11497.15.html (http://www.kxriders.com/forums/index.php/topic,11497.15.html) The Mity vac worked really great for this too. http://www.amazon.com/Silverline-Elite-Hand-Vacuum-Pressure/dp/B004BYGSJI/ref=sr_1_10?ie=UTF8&qid=1372736900&sr=8-10&keywords=mityvac (http://www.amazon.com/Silverline-Elite-Hand-Vacuum-Pressure/dp/B004BYGSJI/ref=sr_1_10?ie=UTF8&qid=1372736900&sr=8-10&keywords=mityvac)
Title: Re: pressure/vacuum test?
Post by: sandblaster on July 01, 2013, 04:12:29 PM
I'm wondering... Since it only has to hold 7lb have you tried some black RTV?
Title: Re: pressure/vacuum test?
Post by: Toom038 on July 02, 2013, 01:41:13 PM
I found a plug in the plumbing section at my local Ace hardware store. It worked fine. No leaks. Thanks for the info here. I got her running really well now thanks to the knowledge of you guys. It was the float height that was screwing things up. Checking it externally found the issue.