Vacuum problem still there! Hopeless!

Old Man Rock asked the following questions:

>>While stuck at the too high idle, what is effect of adding some choke?

Full choke will lower the rev just a tiny bit. Kills the engine at idle.

>>If carbs are like the image shown below, which is the "hidden" pilot air jet referred to?

Not seen in that pic. Here it is...

It is item #10 in the pic.

Fooled around with it today. Literally flooded the carb holders and carbs with WD40 as it idled. No change-no smoke. Tried the same as it revved-same result. I have discovered that if I leave it revving high as it does, it eventually comes down on it's own. Takes maybe 10 seconds.

Now, this peaked my interest! As it starts to come down, there is a click or tick or clack, then it comes down. Almost as if someting hung up is letting go before it can come down to idle. Unfortunately, it has a loud exhaust and I can't quite tell where this noise is coming from. Can....well, can a butterfly still be open if the linkage is closed? Can it hang up on something and not follow the linkage? I know that some car carb butterflys are spring loaded to the linkage. Or could the symptoms becaused by a hanging slider?

I don't think having a slide hanging open will cause if to rev if the butterfly is closed. Now if 1 of those butterfly shafts is hanging up, it will try to hold all 4 open as well do to the linkage. Do you have the air box or pods off so you can look into the rear air horn area when running? I don't think you can see past the slide to see if a butterfly is open, but you should see the slides all come back to the same level. Maybe make a mark on the shaft at the base Idle setting and see if it returns correctly to this mark each time?
Battle on.

Yanked the carbs back off today. Couldn't find anything suspicious.

Phone rang, and while talking I started turning the (now free) throttle cable back and forth at the grip. It had been my assumption that the throttle cable was snapping back to full closed when I released it as it revved. It both sounded and looked like it was fully closing, and I still mostly believe that.

But, while free from the carbs, I noticed that the cable hangs up, slightly, at about the halfway point in it's travel (hummm...just about at the point where the rev takes over). I can force it through this hangup easily with the grip, but if I try to pull it through with the little ball on the other end, it's a little bit difficult.

It's hard for me to believe that the springs on the throttle shafts can't pull through this slight hangup, but at this point I'm considering everything! Opinions? Also, what's a good easy to find lube for the cable? Thanks!

You have vacuum gauges?

Reasoning, ideal operations, with no coke applied your vacuum would be ~ 20cmHg... If the vacuum is way down ~ 5-10cm, then your choke circuit is still in operation...

NOTE: I'm not saying you forgot about the choke lever, I'm meaning internally the choke circuit itself is whacky....

Just ran into this today where after warming up the engine, hooked up my gauges and as mentioned above way low... I was like WTF.... Then I realized the sucking sound with the tops off the carb was due to the choike still on.... DOH!

Yup, the coke lever was still on a tad. Switched off and my vacuum jumped right up where they out to be....

Just a thought... Maybe different on your setup/carbs...

OMR

You can get quality cable lube from any motorcycle shop and nearly every online vendor. I have one of the Motion Pro tools that makes the job a breeze. They typically sell for about $10, and I think it would be a bargain at twice the price.

You may want to replace the cable as it may be frayed in the housing and could stick at WOT and scare the #&*^) out of you, and at the same time inspect/ lube the handle bar where the grip twists/ upper throttle cable guide.

Motor Head wrote:

You may want to replace the cable as it may be frayed in the housing and could stick at WOT and scare the #&*^) out of you, and at the same time inspect/ lube the handle bar where the grip twists/ upper throttle cable guide.

Yes -- and new cables are relatively inexpensive, and available from Z1E.

Lubing is important, and the lube tool mentioned is excellent, but lubing won't help an internally frayed cable.

Good Luck!

Been busy with other things, but I got back to it today and removed the cable completely from the grip and carbs. The cable by itself is very smooth (and the springs at the butterflys are still nice and strong). Turns out that it's the grip itself. It spins freely on the bar, but the nylon (I guess?) plastic part at the inner end of the grip was turning rather tightly in the black plastic channels that hold the grip to the handlebar. I cleaned a lot of crap out of the channels, then lubed it all up with some spray chain wax (an odd choice for a lube I guess but it works fine).

Turns much more freely now without the centuralized hangup I mentioned earlier. Still, it's not as free as would be fully desired, but I have verified that (without the engine running at least), it snaps back to idle quite strongly.

Nothing was done with the carbs this time (as I saw nothing to do), except I backed all the pilot screws out another 1/2 turn (total of 2-1/2 turns out on all of them).

I will put it all back together tomorrow, then crank it up and see what happens.

had a frued cable on mine once, got me a speedin ticket for it, my guess is frayed cable, get a new one

I'm assuming it's a single pull cable without a return pull cable, if so...

I know it's a hard reach especially on a 4 cylinder with the air box in, but can you not just (eliminate the cable from suspect) by not hooking it up, and reach in and flip the throttle open by hand a few times to see if it returns to idle properly.

May I suggest that you not use chain wax as a throttle as it is fairly thick and sticky. Any good cable lube or motor oil will work well. I prefer DuPont Dry Teflon spray. It does not attract dirt and is very slippery.