idle issues

[trantony]

Ok, all you brainiacs out there! Need help. Having issues with the fat girl idling. Got a "97 Tourer, all stock with about 63k miles on ticker. Runs fine w/ 30-38 mpg depending on wrist action. On cold start she idles about 400 rpm, (extremely low, I know) but when she heats up idles goes up to between 1200 and 1500 rpm. It wavers between these figures. When I start with idle at 900 rpm (recommended) she idles between 1400 and 1700 rpm when engine heats up. Would this be a possible slow speed jet clogged, or possibly a stuck float. How would one check for these issues. All comments and suggestions welcome and greatly appreciated.
Thanx,
Leon
Ride safe and keep the shiny side up and the rubber side down.

[Grandpot]

You're thinking right.  It most likely is a carb problem.

First check for vaccuum leaks in the vaccuum lines and at the "O" ring connections on the intakes.  This is a little tricky to do because of the confined spaces.  Spray a SMALL amout of carb cleaner or ether at each connection and along the entire length of each line.  Do one spot at a time.  If there is a vaccuum leak the RPM will increase when the offending spot is sprayed.

Be real careful.  You will be spraying around sources of ignition.  Also, if you spray too much, the vapors may be drawn into the air box by the normal route and raise the RPM and act like a vaccuum leak.

Given the age and miles on the bike, if you have never replaced the vaccuum lines, you are due.

If you don't find any leaks, put fresh gas in the tank with a strong dose of Sea Foam or Techron and ride around for awhile.

Good luck. 

[Kingbee]

I'm thinking vacuum leaks also.  Your idle speed should be set hot, at about 900 RPM.  If your cold start idle becomes un-stable, that's what the enricher/fast idle cuicuit is all about....

[98valk]

www.factorypro.com    cv carb tunning
NOTE: A rich problem gets worse as the engine heats up.
If the throttle is lightly "blipped" at idle, and the rpm drops below the set idle speed, then rises up to the set idle speed, the low speed mixture screws are probably set too rich: try 1/2 turn in, to lean the idle mixture.
NOTE: A lean problem gets better as the engine heats up.
If the throttle is lightly "blipped" at idle, and the rpm "hangs up" before dropping to the set idle speed, and there are no intake leaks and the idle speed is set at less than 1000 rpm, the mixture screws are probably too lean: try 1/2 turn out, to richen mixture. Be sure there are no intake leaks and the idle speed is set at less than 1000 rpm!

check for vacuum leaks as already mentioned. Also check intake manifold o-rings

[Madmike]

thanks for the link

[Mr.BubblesVRCCDS0008]

Check all clamps on the intake assembly most will loosen after a while. You have clamps from airbox to carbs,carb to intake runners (2 clamps) on these. Also if you spray water from a squirt    bottle at the base of the intake where the o rings live it will also let you know if there is a leak. The water will seal to leak for a moment and the ilde will change. It is much cleaner and safer than other methods. I've use WD-40 with the spray tube for this and it works good also  and IMHO is safe to use also, just messy.

[trantony]

Hey guys, thanx a lot for the input. I plan to check for vacuum leaks today, and also reset the air mixture setting. CA, it does hang at fast idle momentarily after blipping throttle. Think i'll try closing air down a bit and ride for a spell. Oh, one more thing. Sorry, I forgot to mention she's been desmogged and had all new vacuum lines installed for about 30k miles. I will post my findings when I get results. Thanx again guys.
Ride safe and keep the shiny side up and the rubber side down.
Leon

[98valk]

also check the petcock vacuum diaphragm (PVD). It might be worn, thereby leaking vacuum and causing a lean condition by not fully opening the fuel diaphragm. Mine is worn after only 19k miles. The bike has not run right for 2 yrs, the final thing came to the PVD after somebody wrote about similar operational conditions and their PVD was split.  The PVD is constantly vibrating and mine was worn near the center pivot point. the base material was there yet the rubber coating was gone. 2x eyepiece revealed this. I have order parts and will be installing a snubber which will reduce the vibration. PVD repair kits are big business for K&L. The valkyrie kits are always sold out, about $15, had to get one for the CBR1000F for $17, diaphragms are the same. no need to get the $30 oem cover kit which provides none wearing parts.

[Grandpot]

CA,

Can you supply a link for K&L or a more descriptive name.  I'm interested in the PVD for $15.

[trantony]

Guys,
Checked all vacuum lines and caps for vacuum leaks and had none. Just readjusted air mixture screws from 1 3/4 turns 2 1/4 turns out. Also syncronized carbs. I did however notice that when I started bike and added hemostat to #6 vacuum line to fuel petcock as directed, it would still run out of gas. CA, I think you may have something there with the daighram leaking. Why else would it run out of gas if the line was clamped after the bike was running? I tried 3 times, making sure the hemostat was completely colapsing tubing. It would still run out of gas. Must be a leak in diaghrm. You think! Where do you get these kits again?
Thanx,
Leon

[98valk]

Guys,
Checked all vacuum lines and caps for vacuum leaks and had none. Just readjusted air mixture screws from 1 3/4 turns 2 1/4 turns out. Also syncronized carbs. I did however notice that when I started bike and added hemostat to #6 vacuum line to fuel petcock as directed, it would still run out of gas. CA, I think you may have something there with the daighram leaking. Why else would it run out of gas if the line was clamped after the bike was running? I tried 3 times, making sure the hemostat was completely colapsing tubing. It would still run out of gas. Must be a leak in diaghrm. You think! Where do you get these kits again?
Thanx,
Leon

if there is no vacuum, the valve will close and then no fuel.  I'm suggesting, as was my case, a constant on and off again lean condition caused by the vacuum diaphragm not fully opening or only partially opening due to the vacuum leak.

[trantony]

Ok guys,
Here is latest update on idle issue. I got to brainstorming and decided to put a vacuum gage on the petcock to see if it held. Well, it doesn't, in fact it leaks down pretty quick. Is this a definite indication of a leaking diaghram? Comments anyone.
Thanx,
Leon

[98valk]

CA,

Can you supply a link for K&L or a more descriptive name.  I'm interested in the PVD for $15.

K&L Supply is the company name. Their website is very limited, however their customer # is very helpful.

#18-5254 (actual K&L part # for CBR1000F and other bikes, diaphragms and spring are the same, I just received this kit, it has extra o-rings not needed for our bike.) (Tucker Rockey # TR29-2506) more $$$ but all that is avail right now
http://www.cyclepages.com/ProductGroupDisp.aspx?ProductGroupID=4001277

For Valkyrie
TR29-2725 (actual tucker rockey part #)  (K&L 18-5018 is the K&L #)  cheaper $$ but not avail right now. It is listed on www.directlineparts.com
http://www.powersportsuperstore.com/K-L-SUPPLY-CO-PETCOCK-REPAIR-KIT-MULTIPLE-APPS-SEE-p/tr29-2725.htm    

I received my kit #18-5254 from www.directlineparts.com    not on their site, just give the part # to the phone rep.

[98valk]

Ok guys,
Here is latest update on idle issue. I got to brainstorming and decided to put a vacuum gage on the petcock to see if it held. Well, it doesn't, in fact it leaks down pretty quick. Is this a definite indication of a leaking diaghram? Comments anyone.
Thanx,
Leon

that's what mine did using a mity-vac. Couldn't even silicone it to be leak free. new kit solved it.

also picked up a new screen filter, 16952-MZ0-003. It comes with the petcock to tank o-ring.

[98valk]

http://daughertymotorsports.com/howto/tankvalve/tankvalve.html