[Road Rash]

I figured fuel starvation because it started up and ran fine for about 3-4 miles then started stumbling a bit. I noticed that I had left the choke partially on. When I turned the choke off it didn't make much difference at first, but soon after found that by turning choke to full on or almost so, that it ran smoother for a while. I recently did the decalifornication of the bike, and it seemed to run well. I thought the removal of the epa canister and tubes as per the article "DECALIFORNICATION OF A KLR". would solve my problems, after originally letting the bike tip over, I had the same symptoms. Prior to that it ran like a top (it has 3300 miles ,I'm the second owner).
The bike would rev pretty good then started acting like the fuel had just turned off, then would run again a split second later. I was able to limp the bike back home by turning the choke full on and it would pull third gear about 40 mph on the flats.
I'm thinking about checking the fuel petcock vacuum first maybe, then maybe the duckbill filter at the carb.
Have any of you had the same problem? I would be very grateful for any insight as where to start. As I said the first 4 miles or so it ran sweet through all gears through 65-70 mph at times.
Thanks for your help.
Jeff

 

[Six8five]

I’d start with the petcock
Check vacuum line, apply vacuum, check for flow.
If it’s good move on to the carb.
The wise ones will drop links and give specifics, you can use the search and read up, many others have had the same fun.

 

[Kevin Graham]

Float bowl or needle sticking and perhaps needs a quick spray of carb cleaner.

 

[Road Rash]

I’d start with the petcock
Check vacuum line, apply vacuum, check for flow.
If it’s good move on to the carb.
The wise ones will drop links and give specifics, you can use the search and read up, many others have had the same fun.

Thanks six8five for your response. I'm new to the KLR and have had the tank off several times to get to the carb and fuel lines etc. I'm tired of having to take off the side fairings and reinstall them. It may seem minor, but I hate trying to get them all to fit right and back in place. I wonder if the tank can be removed by just loosening some of the attachments (like I said, it's minor, but seems like a PITA. Anyway, back to the real problem. Is it possible to pull the fuel line off and motor the engine with the starter to get a good vacuum test? I imagine the vacuum petcock is pretty reliable, it's been in use on these for quite a while. If for some reason it is the petcock, what is a reasonable fix? Are they easy to repair, or are there any after market petcocks recommended? Thanks again for responding

 

[Road Rash]

Float bowl or needle sticking and perhaps needs a quick spray of carb cleaner.

Yeah Kevin, my greatest fear. I have my cross and wooden stake out, I hate cracking open carbs. I have an old 78 Kaw 650 B1 with four carbs just waiting for attention (for years?). Oh well, I guess it is inevitable. I have heard about the duck bill filter on the carb intake as well, guess it'd be a good time to get acquainted. I imagine I can find some good carb rebuilds on this forum, but I guess I'll have to invest in a good maintenance manual for the bike. Thanks for checking in. It's much appreciated

 

[Kevin Graham]

Yeah Kevin, my greatest fear. I have my cross and wooden stake out, I hate cracking open carbs. I have an old 78 Kaw 650 B1 with four carbs just waiting for attention (for years?). Oh well, I guess it is inevitable. I have heard about the duck bill filter on the carb intake as well, guess it'd be a good time to get acquainted. I imagine I can find some good carb rebuilds on this forum, but I guess I'll have to invest in a good maintenance manual for the bike. Thanks for checking in. It's much appreciated

You don't even have to take the tank off. Just loosen choke and throttle cables and the boots and you can rotate the bowl toward you and same opposite way. I did the jet mod without removing anything.

 

[Six8five]

Thanks six8five for your response. I'm new to the KLR and have had the tank off several times to get to the carb and fuel lines etc. I'm tired of having to take off the side fairings and reinstall them. It may seem minor, but I hate trying to get them all to fit right and back in place. I wonder if the tank can be removed by just loosening some of the attachments (like I said, it's minor, but seems like a PITA. Anyway, back to the real problem. Is it possible to pull the fuel line off and motor the engine with the starter to get a good vacuum test? I imagine the vacuum petcock is pretty reliable, it's been in use on these for quite a while. If for some reason it is the petcock, what is a reasonable fix? Are they easy to repair, or are there any after market petcocks recommended? Thanks again for responding

You can pull vacuum with your lips
When you pull on it fuel will flow.
This is a problem others have had including me.
Most replace the vacuum operated for a non vacuum and cap off the line.
Don’t be scared of the carb the CV40 is an easy one to work on RMATV has a great video on YouTube.
Taking the tank off will get easier, you can get it off only removing one side faring you don’t have to remove both but it is easier.
You can pour gas down the hose to the carb to fill the bowl then crank and see how it runs it will run a couple minutes before the bowl goes dry.
A Clymer manual is what you want it will make things easier but YouTube is hard to beat.

 

[pdwestman]

Read this,

Care & Feeding Of The Keihin Carb

Read & watch these,

KLR Keihin CVK40 carb Explained video

I did not have anything to do with the production of this video and I could argue some of the finer points, terminology and descriptions that the author uses in various portions of the video. But I currently can not and do not Want to learn how to get into submiting pics and vids in these...

www.klrforum.com

"Care And Feeding Of The CVK40"

If there's a moderator within the sound of my keyboard, this link should be stickied, IMHO: Care & Feeding Of The Keihin Carb This primer on the CVK40 (and generally, all CV carbs) has bounced around from elusive, and sometimes obsolete, websites; recommend keeping track of the link, perhaps...

www.klrforum.com

 

[Road Rash]

You can pull vacuum with your lips
When you pull on it fuel will flow.
This is a problem others have had including me.
Most replace the vacuum operated for a non vacuum and cap off the line.
Don’t be scared of the carb the CV40 is an easy one to work on RMATV has a great video on YouTube.
Taking the tank off will get easier, you can get it off only removing one side faring you don’t have to remove both but it is easier.
You can pour gas down the hose to the carb to fill the bowl then crank and see how it runs it will run a couple minutes before the bowl goes dry.
A Clymer manual is what you want it will make things easier but YouTube is hard to beat.

Thanks again for your reply. I just wanted to be clear if there is typically a problem with these vacuum operated petcocks? It sounds like you've replaced yours with a manual one. If they are problematic, I saw manual ones for sale on Eagle Mikes site. I know that mine operates, anyway, I won't tell you about the guy that started his KLR without the fuel line connected and found a good stream of fuel coming from the petcock, I, he almost had a heart attack when he saw it streaming out, I, mean he keeps a fire extinguisher close by now. This bike has not seen much in the way of dirt in it's first 3300 miles, but I'll pull the air filter and replace it if necessary. If I find the cleaner dirty, will start pulling the carb. I've heard a lot of discussion on this forum about in line gas filters. Seems like that could stop some problems. Anyway you've given me some direction and I'll start from the top. Thanks again

 

[Six8five]

Thanks again for your reply. I just wanted to be clear if there is typically a problem with these vacuum operated petcocks? It sounds like you've replaced yours with a manual one. If they are problematic, I saw manual ones for sale on Eagle Mikes site. I know that mine operates, anyway, I won't tell you about the guy that started his KLR without the fuel line connected and found a good stream of fuel coming from the petcock, I, he almost had a heart attack when he saw it streaming out, I, mean he keeps a fire extinguisher close by now. This bike has not seen much in the way of dirt in it's first 3300 miles, but I'll pull the air filter and replace it if necessary. If I find the cleaner dirty, will start pulling the carb. I've heard a lot of discussion on this forum about in line gas filters. Seems like that could stop some problems. Anyway you've given me some direction and I'll start from the top. Thanks again

The petcock has a small rubber diaphragm, it does not like ethanol, unless it had ethanol free gas in it, then it’s suspect.
Ethanol free fuel will keep your bike happier.

 

[Road Rash]

Read this,

Care & Feeding Of The Keihin Carb

Read & watch these,

KLR Keihin CVK40 carb Explained video

I did not have anything to do with the production of this video and I could argue some of the finer points, terminology and descriptions that the author uses in various portions of the video. But I currently can not and do not Want to learn how to get into submiting pics and vids in these...

www.klrforum.com

"Care And Feeding Of The CVK40"

If there's a moderator within the sound of my keyboard, this link should be stickied, IMHO: Care & Feeding Of The Keihin Carb This primer on the CVK40 (and generally, all CV carbs) has bounced around from elusive, and sometimes obsolete, websites; recommend keeping track of the link, perhaps...

www.klrforum.com

Great read and great video! Great info. No excuses, I'll be pulling the carb for a cleaning and intro. Thanks, great motivator. Thanks

 

[KLR Kool-Aid!]

I had a petcock diaphragm wear out at about 60K, and the symptoms were similar. Check out post #33 on the thread Pilot jet issue? (2nd opinion, please). I like having the vacuum operated petcock, so I ended up rebuilding it with EM's kit and I've had no problems since. ( Full disclosure: I carry a "spare" manual raptor petcock in my saddle bag "just in case".)

 

[pdwestman]

I recently did the decalifornication of the bike,

I will ask if you PLUGGED the rubber elbow near the RH front corner of the battery box to prevent dirty air from entering into the Clean Side of the air box? Not that it would alter the running in the short term, but for engine longevity in the long term.

Did you also remove the exhaust AIS plumbing?
Maybe the decalifornication cap on the top front Brass nipple of the carb has popped off or rotted, causing a vacuum leak?

 

[PeteK]

Also remember that there is a SMALL fuel strainer inside the end of the fuel hose where it attaches to the carb fitting. Make are that is not blocking flow.

 

[pdwestman]

I'm thinking about checking the fuel petcock vacuum first maybe, then maybe the duckbill filter at the carb.

Also remember that there is a SMALL fuel strainer inside the end of the fuel hose where it attaches to the carb fitting. Make are that is not blocking flow.

Did you over-look some info in his opening post, PeteK?

 

[PeteK]

Apparently. "Duckbill" didn't jump out at me.

 

[Road Rash]

I will ask if you PLUGGED the rubber elbow near the RH front corner of the battery box to prevent dirty air from entering into the Clean Side of the air box? Not that it would alter the running in the short term, but for engine longevity in the long term.
YES, I did make sure to seal off the airbox (with permanence in mind). It's air tight there.

Did you also remove the exhaust AIS plumbing?
Maybe the decalifornication cap on the top front Brass nipple of the carb has popped off or rotted, causing a vacuum leak?
I didn't do anything with the exhaust air injection. I didn't think it necessary. I'm planning to use EM air injection plug when I have some scarce spare time. I will definitely have a look at the front of the carb. As soon as I can get the bike on the lift. Old GL1100 up there now demanding attention.

 

[Road Rash]

Also remember that there is a SMALL fuel strainer inside the end of the fuel hose where it attaches to the carb fitting. Make are that is not blocking flow.
Didn't know that. I'll check that when I get it on the lift. Thanks

 

[Road Rash]

Thanks everybody for your responses, I'll get back to all of you as soon as I can get it on my lift. As I said I've been trying to get my 82 GL1100 off the lift, but every time I fix something I find something else needing to be addressed. Waiting for more parts and hopefully have it off soon.
It's very evident that I will need to check the whole fuel system starting with the petcock, duck bill fuel filter, carb inspection and cleaning. You have all given me excellent information (video links, et al.) and I'm very grateful. It'll be a week or two before I get back to you all about how it's going or went. I have too much on the plate before then. I'll update when I can.🔧

 

[KLR Kool-Aid!]

Just a note - it you can get it to run off of a "temporary" fuel source (e.g., pouring fuel into the fuel line below the petcock), it's probably the petcock causing you heartache, so you may want to try that before pulling the carb. Good luck and let us know what you find.