'broke' my carb

[JRC]

I just bought my first KLR this week. It's a '99, has 5k miles, and is in good shape. I'm the 3rd owner. It's my 15th bike in 30 years. I look forward to participating in the newsgroup, probably with lots more questions than answers in the beginning. Now for my question. The bike idles a bit rough, surges at freeway speeds, and over revs between shifts. It backfires,and the plug is bone white. I figured the bike is running lean, and decided to drill out the pilot mixture plug and turn the screw about 3 turns out (BTW, there is a Tech Q&A on KLR valves and idle mixture in this month's Rider). After loosening the carb and rotating it, I could see someone had already drilled out the plug. The screw was set at 4 full turns out. This seems like a lot, based on my experience with other bikes. On the KLR does turning the screw out make the pilot circuit richer or leaner? (some bikes are one way, some the other.) Is there a typical setting? Any ideas on what else I can do to correct the lean behavior? (I also checked the exhaust flanges and they seem OK.) Thanks in advance for your help to a new owner. JRC in MN

[Mike Torst]

Welcome aboard! TO cut the chase, it sounds like the typical lean condition of a stock carb. You will do yourself well to check the FAQ. http://www.bigcee.com/klr650faq.html Mike Torst Las Vegas -----Original Message----- From: JRC [mailto:jrc1515@...] Sent: Sunday, July 04, 2004 3:50 PM To: DSN_klr650@yahoogroups.com Subject: [DSN_klr650] My "new " KLR - and a question I just bought my first KLR this week. It's a '99, has 5k miles, and is in good shape. I'm the 3rd owner. It's my 15th bike in 30 years. I look forward to participating in the newsgroup, probably with lots more questions than answers in the beginning. Now for my question. The bike idles a bit rough, surges at freeway speeds, and over revs between shifts. It backfires,and the plug is bone white. I figured the bike is running lean, and decided to drill out the pilot mixture plug and turn the screw about 3 turns out (BTW, there is a Tech Q&A on KLR valves and idle mixture in this month's Rider). After loosening the carb and rotating it, I could see someone had already drilled out the plug. The screw was set at 4 full turns out. This seems like a lot, based on my experience with other bikes. On the KLR does turning the screw out make the pilot circuit richer or leaner? (some bikes are one way, some the other.) Is there a typical setting? Any ideas on what else I can do to correct the lean behavior? (I also checked the exhaust flanges and they seem OK.) Thanks in advance for your help to a new owner. JRC in MN

[dooden]

--- In DSN_klr650@yahoogroups.com, "JRC" wrote:

> I just bought my first KLR this week. It's a '99, has 5k miles, and > is in good shape. I'm the 3rd owner. It's my 15th bike in 30 years. > I look forward to participating in the newsgroup, probably with lots > more questions than answers in the beginning. > Now for my question. The bike idles a bit rough, surges at freeway > speeds, and over revs between shifts. It backfires,and the plug is > bone white. I figured the bike is running lean, and decided to > drill out the pilot mixture plug and turn the screw about 3 turns out > (BTW, there is a Tech Q&A on KLR valves and idle mixture in this > month's Rider). After loosening the carb and rotating it, I could see > someone had already drilled out the plug. The screw was set at 4 > full turns out. > This seems like a lot, based on my experience with other bikes. > On the KLR does turning the screw out make the pilot circuit richer > or leaner? (some bikes are one way, some the other.) Is there a > typical setting? > Any ideas on what else I can do to correct the lean behavior? > (I also checked the exhaust flanges and they seem OK.) > > Thanks in advance for your help to a new owner. > JRC in MN

2 ~ 2.5 turns out is normal. The over rev's part got me thinking maybe a slide diaphram going south maybe ? Maybe the carb boot were/are leaking, or maybe the pilot circuit is plugged and adjusting the needle is not doing anything for you, but if you already bottomed the needle (gently I hope) and cycled it back out. http://members.aol.com/roundr1/CVK40.html Lots of info on the internals of the CVK40 http://www.sagebrushmachine.com/pilottool.html How it hit that sweet spot on the pilot circuit. I am sure somebody with more knowledge will pipe in and offer a better reply than I, Dooden A15 Green Ape Yooperland

[Matt]

My guess is that you are idling rich and running lean. Check your airbox and filter - is it the original filter and has the airbox been opened up? Is it the stock exhaust? I think someone tried to richen it solely with the pilot screw which will richen the idle (making it run rough) but not have a huge effect on the running mixture. Turn the pilot screw back down to 2.5 or 3 turns and then shim the needle. There's a lot of info out there on shimming the needle but basically take the black top cover off lift the needle out and start with one #4 washer under the head of the needle and see what happens. Check the size of the slide hole while your in there (the off center one can be drilled out to 1/8" for better throttle response). Not sure about the overspeed and backfiring but you might want to open the "anti-backfire" diaphragm (can't remember the right name) on the back (left) side of the carb. The rubber on mine was dissolving leaving just the mesh underneath. Matt

--- In DSN_klr650@yahoogroups.com, "JRC" wrote: > I just bought my first KLR this week. It's a '99, has 5k miles, and > is in good shape. I'm the 3rd owner. It's my 15th bike in 30 years. > I look forward to participating in the newsgroup, probably with lots > more questions than answers in the beginning. > Now for my question. The bike idles a bit rough, surges at freeway > speeds, and over revs between shifts. It backfires,and the plug is > bone white. I figured the bike is running lean, and decided to > drill out the pilot mixture plug and turn the screw about 3 turns out > (BTW, there is a Tech Q&A on KLR valves and idle mixture in this > month's Rider). After loosening the carb and rotating it, I could see > someone had already drilled out the plug. The screw was set at 4 > full turns out. > This seems like a lot, based on my experience with other bikes. > On the KLR does turning the screw out make the pilot circuit richer > or leaner? (some bikes are one way, some the other.) Is there a > typical setting? > Any ideas on what else I can do to correct the lean behavior? > (I also checked the exhaust flanges and they seem OK.) > > Thanks in advance for your help to a new owner. > JRC in MN

[JRC]

The exhaust is stock, as is the air intake. I cleaned and reoiled the air filter per the owners manual, thinking that would enrichen the mixture by cutting down the airflow a small amount. I currently have the pilot set to 3 turns out. I checked and adjusted the throttle cables, the chock cable, and the clutch. It still surges at about 55 mph in high gear and over revs on shifts. If I just pull in the clutch at 3000 rpm and chop the throttle it stays at the same rpm and then take a long time to drop to idle speed (3-4 seconds).

> I think someone tried to richen it solely with the pilot screw >which will richen the idle (making it run rough) but not have a >huge effect on the running mixture.

Currently, I have new gas, and Seafoam in the tank. If that doesn't work, I may pull the carb and take it apart. The fact that the pilot screw was set at 4 turns tells me that someone was working on it, and he may not have known what he was doing. There may be other surprises for me inside the carb. I wonder if a sticky slide is causing the over rev and the lean condition

> Not sure about the overspeed and backfiring but you might want to > open the "anti-backfire" diaphragm (can't remember the right name) > on the back (left) side of the carb. The rubber on mine was > dissolving leaving just the mesh underneath.

Many carbs have a decelleration valve on them, to control backfire and engine stalling under hard decel. Does turning the pilot screw out enrichen or lean out the idle mixture? The pilot screw controls air on some types of carbs, fuel on others. Thanks. This is a great group. Jim

[Guy B. Young II]

On this carb, it enrichens the mixture. Guy A16 At 10:10 PM 7/5/04 -0000, JRC wrote:

>Does turning the pilot screw out enrichen or lean out the idle >mixture? The pilot screw controls air on some types of carbs, fuel >on others. > >Thanks. This is a great group. > >Jim

[dooden]

--- In DSN_klr650@yahoogroups.com, "JRC" wrote:

> Does turning the pilot screw out enrichen or lean out the idle > mixture? The pilot screw controls air on some types of carbs, fuel > on others. > > Thanks. This is a great group. > > Jim

Out = richer 3 full turns seems excessive to me, I am just a tad over 2 full turns and I dont get surging, but again I am the guy that uses Chainsaw Bar Oil on his filter, and thats some tacky stuff. Dooden A15 Green Ape

[bigfatgreenbike]

jrc1515@... wrote:

>The exhaust is stock, as is the air intake. I cleaned and reoiled >the air filter per the owners manual, thinking that would enrichen >the mixture by cutting down the airflow a small amount. > >I currently have the pilot set to 3 turns out. I checked and >adjusted the throttle cables, the chock cable, and the clutch. It >still surges at about 55 mph in high gear and over revs on shifts. >If I just pull in the clutch at 3000 rpm and chop the throttle it >stays at the same rpm and then take a long time to drop to idle speed >(3-4 seconds). > >

This REALLY sounds like an air leak. One way to find out where, is to idle the motor and spray starter fluid (sparingly) on the intake boot- if the motor is sucking in air here the idle will rise. Devon

[JRC]

--- In DSN_klr650@yahoogroups.com, bigfatgreenbike

> This REALLY sounds like an air leak. > > One way to find out where, is to idle the motor and spray starter

fluid (sparingly) on the intake boot- if the motor is sucking in air here the idle will rise.

> Devon

I was thinking air leak, too. Although, it's been my experience that when there's an air leak on a bike, they won't run at all unless the throttle is gunned. KLRs may be different. This bike will idle, but it has a periodic misfire and and stumbles up and down about 200 rpm total. I inspected the hoses and intake manifold and didn't see anything obvious. I haven't tried the starter fluid trick. I may try WD40, which is a bit less flammable. Thanks.

[john W]

I was removing my gas tank in order to put in my iridium plug and wire my 12 volt auto-lighter into my mini-dash..The fuel line of course was on the gas tank pretty tightly. I used a screw driver to gently get the hose to start moving off the metal tube of the tank. I thought I got it most of the way of and started pulling w/my hand. It jerked off and I couldn't stop quickly enough..It came off the tank, but kept going and I managed to break off the plastic "L-type fitting" that's attached to the carburator. I couldn't believe it !!! So now I'm just having to wait until tomorrow (even ronayers is closed) to look for the part. However since I have the carb off, I noticed another L-type fitting a little higher on the carb that appears to be the same part number (92005-1120). Strangely, there's no hose or anything attached to that one which is a greyish color (I broke the black one) Anyway, I'm considering just switching the broken one with the grey one and just using that one . Does anyone know what the grey one does and if it's kosher to switch ? thanks ! ===== Sammamish, WA '94 klr650 '03 ZR-7S '86 klr250 '86 yam it200n KLR 650 FAQ's http://www.bigcee.com/klr650faq.html __________________________________ Do you Yahoo!? Yahoo! Mail is new and improved - Check it out! http://promotions.yahoo.com/new_mail