either a carb or petcock problem, HELP!

[trantony]

Calling all carb techs! Having issues with my "97 Valk idling at about 400rpm on cold start. When it heats up it idles at about 900-1100rpm. It fluctuates. If I set idle at 900 when I first start it, when it gets hot it idles from 1500-1700rpm, still fluctuates. I was wondering if I can check the petcock for leakage by connecting a mity-vac to the vacuum line at the #6 intake. I have done this, but it leaks down in about 4 seconds. Not sure I understand what the indications are of this? The bike has 64K miles on it, has been desmogged, good vacuum lines, and carbs sync'd. The air intake is 1 3/4 turns out. It runs great on hiway getting about 34mpg @ 70mph. Anyone got any ideas what is going on here? Thanx in advance. Ride safe and keep the shiny side up and the rubber side down.
 

[BonS]

My 2 cents - Not scientific but I can pull the #6 vac line to the petcock and then, with my mouth, pull a vacuum on a good petcock and it'll stick my tongue to it indefinitely. You likely need to rebuild/replace it. I'm no help with the fluctuating idle but someone will come along soon.

[Dennis Klinefelt]

Are you using the choke..??

[Kingbee]

If your line to the petcock is good, then you need to rebuild the petcock.  It should have held a vacuum for a week.........

[Patrick]

There very well could be more than one problem.. The idle shouldn't fluctuate like that and that could a vacuum leak or a low speed jet problem.. [When you mention 1 3/4 turns on the air intake, I don't know what you mean.. I'm thinking your talking about the pilots].. You should be able to control your initial idle speed with the choke/enrichener and its normal for the engine to idle slower when the engine is still cold..

[RTaz]

...replace your intake o-rings...be sure your airbox is on correctly ....be sure that the #6 vacuum line is correct size....and be sure you don't have a float sticking....also you may think about your timing belts....

[FLATSIX]

One question : do you have valance covers?

2 weeks ago I changed the O-rings in the intakes, have put back my valance covers, but I did it in another way as before : I first mounted the sparkplugcaps into the holes, so they fitted perfectly, but then I could not go under the valance covers to put the sparkplug caps firmly on the sparkplugs. I pushed them from on top and mounted the valance covers (so the caps were not fully on the sparkplugs!)

Then I did the synchronising of the carbs : result - when cold the motor idles at 500 rpm and not too steady (needle up and down)

I thought that it was due to the synchronising till I started to ask here on the board how to mount the valances : I redid it, pushed the rubber sparkplug tops firmly on the sparkplugs and then mounted the valances :result - idling with cold motor is like it should 700 - 800 rpm and very quick 900 rpm + idling is steady + bike runs even more better.

SO PLEASE CHECK THIS OUT IF VALANCE COVERS : SPARKPLUGCAPS MUST BE FIRMLY ON THE SPARKPLUGS ) !!
 

[trantony]

Thanx for help guys! I've about come to the conclussion that I may have a couple of problems. Possibly plugged slow jets and a bad petcock. BonS & Kingbee, I think we're on the same page with the petcock rebuild. Flatsix, not using valance covers, but I will check for plug connections. RTaz, what would be the best way to check for sticking carb float? Could this be done by draining float bowls and leaving drains open a few hours? Wouldn't a bad petcock give similar symtoms? I was reffering to the pilot screw adjusments earlier. Dennis, Ive always had to use choke for cold start ups. Isn't this normal?

[Bone]

Ive always had to use choke for cold start ups. Isn't this normal?

I'm in a colder climate and used my choke for most start-ups. This spring I replaced the battery because of age it didn't show any signs of getting tired.
Now I can hit the button and she fires without the choke but I do use it occasionally to increase the idle for a few moments.

[franco6]

here in houston i stop using the choke in march-april ,it starts right up. just let it warm up a bit.

[Medic]

trantony...mines been doing the same thing (97 also). I've got #38 slow jets and a petcock rebuild / cover set...just haven't had the time to do it. My Valk has also been DeSmogged and recently had the valves adjusted and carbs synced. The only thing different I have is right-sided exhaust popping when cold starting..Goes away after warmed up except for minor popping on decel at times. Not sure if I have the vaccuum leak like you or not. Let me know if the new jets and petcock rebuild works for you  . With my schedule...it may be towards the end of July for I get into mine.  Also let me know how many "turns out" on the pilots you find works after the slows switched if you use #38's. The '97's had different carbs and the stock setting is different than other years...so I'm curious on what works when putting the #38 slows in a '97.

[FLATSIX]

Trantony and Franco6, you are not the only ones with problems on the '97 Valk!

I bought mine new and have the same issues - went during all these years several times to the Honda-dealer where I bought my '97 from and asked him about the misfiring from my left exhaust - the only answer that he could give was "that nothing is perfect

and with that I had to do it.

When I open throttle till 2200-2500 rpm I hear misfirings at the left. Another thing : while synchronising the carbs I was 99% of the time turning and adjusting the screws from the 3 left - the right side kept much more steady.

Checked already everything : O-rings,clamps, vacuum etc...... nothing to find but keeps misfiring - if you can find the cause or can cure yours '97- please let me know as I wanted to finally after 12 years ride it without the slight failure she has - for the rest she drives fine, oly the ennoying popping at the left