KLR250 Carb question - KLR650.NET Forums - Your Kawasaki KLR650 Forums Resource! - The Original KLR650 Forum!
KLR650.NET Forums - Your Kawasaki KLR650 Forums Resource! - The Original KLR650 Forum!
Go Back   KLR650.NET Forums - Your Kawasaki KLR650 Forums Resource! - The Original KLR650 Forum! > Other Kawasaki Motorcycles > KLR250 and Super Sherpa Main Discussion
Register FAQ Members List Calendar Mark Forums Read
KLR250 and Super Sherpa Main Discussion

Thread Tools Display Modes
Old 11-06-2017, 01:32 AM   #1
Vincent Baelde
Occasional Poster
Super Cool Since: Oct 2017
Locale: Victoria, Australia
Postings: 3
Vincent Baelde is on a distinguished road
Default KLR250 Carb question

I have a 2004 KLR250, and it's got a coolant line going through the carb. I can't seem to find a manual which has this.
Does anyone know what this coolant line does?

Long version:
My bike seems to idle at different speeds depending on the engine temperature, I very rarely need any choke to start it, but it sometimes dies idling when it's hot.
There's also a clear plastic bubble going from the pump to the carb, and it is half filled with air no matter how long I bleed the system for.
Vincent Baelde is offline   Reply With Quote
Old 11-09-2017, 12:35 AM   #2
kidflyr's Avatar
Super Cool Since: Mar 2012
Locale: Ukiah, California
Postings: 419
kidflyr is on a distinguished road
Question Re: KLR250 Carb question

Welcome to the forum, Vincent!

Appears to me that you have a version with a heated carburetor to prevent icing in cool climates, or possibly just that Kawasaki cut the expense of for the North American market. I have not yet seen one in person though one or two forum members have described this feature on their KLR250's. As I recall a line from the thermostat housing routes to the carburetor, and a line from the carburetor routes to the water pump housing. The plastic bubble in the coolant circuit to the carburetor is not familiar to me, and I would like to think that a previous owner would not be foolish enough to put one of those generic clear plastic fuel filters on a coolant line. That plastic bubble stands out as odd to me.

As compared to bikes without it, this feature should give you more consistent carburetion and coolant temperatures across a broad range of ambient temperatures. The carb heating coolant circuit acts as a mixing circuit similarly to Watt-man's Thermo-Bob but without the higher temperature thermostat.

The idle behavior you mention could be a range of factors that further information would be helpful in determining. First, Kawasaki specifies an idle speed of 1,300RPM, +/-100RPM for all years KLR250. What is the RPM range your bike roams once it achieves operating temperature? Describe the activity of the temperature gauge under normal (or as normal as you experience) idle conditions? Has the idle mixture screw cap (a blank aluminum disc on the underside of the carburetor, 6- or 8-ish mm diameter) been removed, indicating tampering/adjustment by yourself or a prior owner? How recently were the valves adjusted, carburetor cleaned, and what jet sizes are installed in the carburetor? Factory jetting is 35 pilot, 118 main for most regions. An area which I scrutinize more than some riders is the evaporative emissions system on bikes equipped with it, or the vacuum cap on the carburetor's only vacuum nipple, up top. Emissions lines or the vacuum can can develop hairline cracks that result in inconsistent engine behavior because of the slight vacuum leak from the fine crack(s). Testing by installing a snug new vacuum cap (I prefer the vinyl ones here, as they have been less prone to cracking for me) is a quick and easy way to isolate that possibility.

I will check back soon, but I'm split between fire academy and my forestry duties at present, so my response may take a day or two.
Nick was here

Support this awesome resource! Go Premium!

1993 KLR250 * Titanium tibia * Kenda K761 tires * Airbox de-snorkled & opened up * PCV valve * UNI bulk foam filter * Modified exhaust port * 38pilot/135main * Capacitors in parallel with battery * LEDs all around * Jeffsaline's headlight relay * 16 tooth countershaft sprocket/40 tooth rear * WOLO "Bad Boy" horn
kidflyr is offline   Reply With Quote
Sponsored links
Old 11-09-2017, 01:49 AM   #3
Vincent Baelde
Occasional Poster
Super Cool Since: Oct 2017
Locale: Victoria, Australia
Postings: 3
Vincent Baelde is on a distinguished road
Default Re: KLR250 Carb question

Thanks for the detailed response.
This is my first bike and my family aren't bike people, so my maintenance is a bit patchy. I did the valves when I got the bike 8 months ago, and I just recently cleaned my carb and air filter. The carb cleaner I got didn't warn you about rubber parts, so I left it on my slide overnight and it made the diaphragm expand and wrinkle.
I'm going to replace that next week (F*&@# $205 for a replacement slide) and I expect that to fix the stalling. Right now I have the idle cranked way up to keep it from dying.

I sorta just wanted to understand how it worked for future reference, and to know if I should worry about the air in the coolant system.
You're spot on about it coming off the thermostat housing and going into the coolant pump. I think the bubble has no filter in it.
Attached Thumbnails
Click image for larger version

Name:	20171109_172812.jpg
Views:	38
Size:	86.6 KB
ID:	65433  
Vincent Baelde is offline   Reply With Quote
Sponsored links

carb, carburettor, Cooling system, klr 250, klr250, question

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Another A/F Choke Vacuum Carb Question for noob boothbay KLR650 First Generation 6 07-05-2017 11:19 PM
2006 KLR650 carb question Howurd KLR650 Maintenance, Modifications & Technical 15 04-24-2016 03:48 AM
Jetting and Carb Tune Question colebcampbell KLR650 Maintenance, Modifications & Technical 4 04-16-2016 04:31 PM
cylinder head question and carb needle identification ArtSiordia KLR650 Maintenance, Modifications & Technical 6 11-11-2015 01:56 AM
Working on my carb - float gasket question (2009 klr 650) UgleeX KLR650 Maintenance, Modifications & Technical 9 11-07-2015 02:01 PM

Powered by vBulletin®
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
© Copyright KLR650.NETAd Management by RedTyger