engine dies when i open throttle

[Paul]

The problem: My '98 KLR 650 with about 30,000 miles, starts and runs good up to about 4000 RPM, runs bad, raggedy, surging, hesitating, etc between 4000 and 5000 RPM, then smooths out some and revs to redline. It's rideable, I've been riding since May with it this way. Background: A year and half ago, a car hit me on the KLR. Wrecked the radiator and fan, bent the subframe. I wasn't able to ride for almost a year, so the bike sat. Finally was able to ride again and got it running in May. I've put both Sea Foam and Techron in the tank, I tried to clean the carb twice and so finally I brought it to a professional mechanic. He cleaned the carb twice and replaced the diaphram with no change. Along the way, I also re-built the fuel petcock and installed a new fuel filter. I don't even know what else to check. My mechanic suggested maybe the compression release, but I don't see where that could be it. I set the valve clearances about 4000 miles ago, before the accident. New psark plug. Any suggestions? Thanks, Paul Streeter Minnesota

[klrdon@comcast.net]

No real reason to suggest this except the rpm range of poor running seems weird. Ignition module, unless that rpm range is a transition between fuel jet circuits (idle-midrange-main needle jet) and I have no expertise to offer either as the true issue )) Did you put a full rebuild kit in the carb? Don M -----Original Message----- From: Paul Sent: Sunday, October 30, 2011 10:47 AM To: DSN_KLR650@yahoogroups.com Subject: [DSN_KLR650] I'm stumped The problem: My '98 KLR 650 with about 30,000 miles, starts and runs good up to about 4000 RPM, runs bad, raggedy, surging, hesitating, etc between 4000 and 5000 RPM, then smooths out some and revs to redline. It's rideable, I've been riding since May with it this way. Background: A year and half ago, a car hit me on the KLR. Wrecked the radiator and fan, bent the subframe. I wasn't able to ride for almost a year, so the bike sat. Finally was able to ride again and got it running in May. I've put both Sea Foam and Techron in the tank, I tried to clean the carb twice and so finally I brought it to a professional mechanic. He cleaned the carb twice and replaced the diaphram with no change. Along the way, I also re-built the fuel petcock and installed a new fuel filter. I don't even know what else to check. My mechanic suggested maybe the compression release, but I don't see where that could be it. I set the valve clearances about 4000 miles ago, before the accident. New psark plug. Any suggestions? Thanks, Paul Streeter Minnesota ------------------------------------ List Sponsors - Dual Sport News: http://www.dualsportnews.com Arrowhead Motorsports: http://www.arrowheadmotorsports.com List FAQ courtesy of Chris Krok: http://www.bigcee.com/klr650faq.html Member Map: http://groups.yahoo.com/group/DSN_KLR650/app/peoplemap/view/map Group Apps: http://groups.yahoo.com/group/DSN_KLR650/grouplets/subscriptionsYahoo! Groups Links ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1834 / Virus Database: 2092/4584 - Release Date: 10/30/11

[Jeff Khoury]

When dealing with these kinds of problems, first start with the simple stuff. Check the air cleaner/snorkel to ensure there are no blockages. A stumble in the middle of the range is almost always indicative of varnish buildup on the needle or in the main jet pathway. Take the carb off again and pull out the needle. Make sure it's COMPLETELY free of varnish. I've seen some so bad that you have to use steel wool or a polishing wheel on a dremel to remove it. Even a little varnish on the needle will create a stumble. After you're done there, take off the bowl and remove the main jet. You should be able to see light all the way from the main jet holder through the venturi. Use Carb cleaner and a rough pipe cleaner to ream out this passageway. I've even clamped a drill onto the pipe cleaner and spun it slowly for a minute or so to ensure all the varnish is clear. Keep pumping carb cleaner in there (K&W is the best, wear gloves and glasses when using, it will burn your skin) to dissolve the varnish. When you think it's clean... do it again. Re-assemble and I'll bet your stumble will be gone. Once you're to this point, no amount of additive will help you. You gotta do it by hand.

----- Original Message ----- From: klrdon@... To: "DSN KLR650" DSN_KLR650@yahoogroups.com>, "Paul" Sent: Sunday, October 30, 2011 9:37:47 AM Subject: Re: [DSN_KLR650] I'm stumped No real reason to suggest this except the rpm range of poor running seems weird. Ignition module, unless that rpm range is a transition between fuel jet circuits (idle-midrange-main needle jet) and I have no expertise to offer either as the true issue )) Did you put a full rebuild kit in the carb? Don M -----Original Message----- From: Paul Sent: Sunday, October 30, 2011 10:47 AM To: DSN_KLR650@yahoogroups.com Subject: [DSN_KLR650] I'm stumped The problem: My '98 KLR 650 with about 30,000 miles, starts and runs good up to about 4000 RPM, runs bad, raggedy, surging, hesitating, etc between 4000 and 5000 RPM, then smooths out some and revs to redline. It's rideable, I've been riding since May with it this way. Background: A year and half ago, a car hit me on the KLR. Wrecked the radiator and fan, bent the subframe. I wasn't able to ride for almost a year, so the bike sat. Finally was able to ride again and got it running in May. I've put both Sea Foam and Techron in the tank, I tried to clean the carb twice and so finally I brought it to a professional mechanic. He cleaned the carb twice and replaced the diaphram with no change. Along the way, I also re-built the fuel petcock and installed a new fuel filter. I don't even know what else to check. My mechanic suggested maybe the compression release, but I don't see where that could be it. I set the valve clearances about 4000 miles ago, before the accident. New psark plug. Any suggestions? Thanks, Paul Streeter Minnesota ------------------------------------ List Sponsors - Dual Sport News: http://www.dualsportnews.com Arrowhead Motorsports: http://www.arrowheadmotorsports.com List FAQ courtesy of Chris Krok: http://www.bigcee.com/klr650faq.html Member Map: http://groups.yahoo.com/group/DSN_KLR650/app/peoplemap/view/map Group Apps: http://groups.yahoo.com/group/DSN_KLR650/grouplets/subscriptionsYahoo ! Groups Links ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1834 / Virus Database: 2092/4584 - Release Date: 10/30/11

[Jeff Khoury]

Your problem sounds like you need a full carb cleaning. At the very least your transition jets are clogged, and your main/needle may be dirty and/or stuck. Most of the time new jets are not required, but you'll need to do a full teardown and cleaning. If you search the archives of this list, I've posted many times on how to do it. The transition jets are built in to the body of the carb. If you look in the "engine side" of the carb, you'll see three (usually) tiny holes right where the throttle butterfly closes on the bottom side. These "fill in" between the pilot (idle) circuit and the main as you open the throttle. Since they're drilled into the body of the carb, you can't replace them. If they're sealed over with varnish, use a strand from a brass wire brush held in needle-nose pliers to "pop" them open again, then liberally spray K&W carb cleaner down them until you're sure they're open.

----- Original Message ----- From: "Michael Martin" To: "DSN KLR650" DSN_KLR650@yahoogroups.com> Sent: Sunday, October 30, 2011 3:03:21 PM Subject: Re: [DSN_KLR650] Engine dies when I open throttle Don, I would remove and clean (or replace) the carb jets. Mike Martin, Louisville, KY ________________________________ From: gerhardtdon < djgerhardt@... > To: DSN_KLR650@yahoogroups.com Sent: Saturday, October 29, 2011 11:57 PM Subject: [DSN_KLR650] Engine dies when I open throttle I have a 2003 KLR650. I ride the bike about 200 miles a year. The engine starts fine and idles OK. The engine dies when I open the throttle. I installed a new battery and spark plug. I get a good spark when I test it with a spark tester. I drained the carb bowl. I have been using Seaform with each fill up. I checked the FAQ section for help but could not find a solution. Does any oner have a recommendation on items I should check next? Thanks Don G. [Non-text portions of this message have been removed]