Idle staying high

[dgc67]

Over the last few weeks my idle has not been dropping after the bike is warmed up.  Over the last few days it has started sooner and gotten worse.  It hangs up around 1500-2000 rpm.  Any thoughts as to why this would start occurring?

In conjunction with this I have noticed that, usually ONLY on my ride home, by the time I get almost home I notice the fuel filter is almost completely empty.  The bike, other than the high idle, seems responsive.  It is very weird.  This is after about 20 miles on the freeway doing anywhere from 10mph to 90 mph.  It happened yesterday, it was completely empty as far as you can tell.  This morning it will fill right up.  I guess I need to test the fuel pump after it is hot.  Thoughts on that?

[stereomind]

Assuming that nobody has messed with the idle adjustment screw, a high idle would indicate extra fuel/air getting in somewhere.
One possibility is that one of the enrichment plungers got some dirt under it, keeping it from closing all the way. One of the butterflies may not be closing completely... Lesseee.. throttle shaft seals may be going.. Could also be a tight throttle or choke cable.

Another possibility is that you've developed a vacuum leak somewhere. There are a couple of ways to test for that.. One is to gently spray carb cleaner or starting fluid on and around the carbs while the bike is running... This is not a favorite method for a lot of people cause it may damage the engine paint job if you overdo it. But, it will cause the RPMs to fluctuate if the fluid hits a vacuum leak. Another way is to wave a propane torch (unlit!) around the carbs.. If the propane hits the vacuum leak, the RPMs will go up briefly.

I'd check the simple stuff first, like tight cables, enrichment plunger not seating all the way, idle adjustment... Have the carbs been cleaned recently?

As for the fuel filter... I have never seen a V45 close up... Is the filter above the carbs or below?

[dgc67]

No work has been done to the carbs in sometime.  Today I turned the idle screw down and it held the slower idle so far. Weird, almost like it had worked itself up.

My fuel filter is on the left side of the engine, right next to the carbs where I can see it while riding.  Not the stock location for it.
When I put the bike up yesterday evening the filter was EMPTY.
Started the bike this morning the filter was about 1/3 full, like it had filled this 1/3 overnight on its own.
After about 15 miles of riding the filter was so full it does not even have an air bubble.

Now we will see what happens on the ride home.

[hootmon]

The Gen three (I know you don't have one of these) does not have a fuel pump, it is gravity fed. On the pet cock there is a filter over the tube that goes into the tank. It doesn't sound like you are having an issue getting fuel if you are doing 90  at times. But I would not expect to see any air in the filter.. Where would it come from??

[Smoked U]

The Gen three (I know you don't have one of these) does not have a fuel pump, it is gravity fed. On the pet cock there is a filter over the tube that goes into the tank. It doesn't sound like you are having an issue getting fuel if you are doing 90  at times. But I would not expect to see any air in the filter.. Where would it come from??

Vacuum?

[dgc67]

Yeah, it is weird.  From my experience it is not so unusual to see an air bubble in a fuel filter, but it should stay a consistent size.
Right now there is NO air at all.  Later it might be ALL air in there.  I wanna know how I can run 90 mph with a fuel filter that is empty.  I mean, clearly fuel is going through it.

[BudMan]

I added an in-line filter down by the carbs on my V-65 and it NEVER fills completely. However it does stay filled about the same amount all the time.

[dgc67]

Left for home yesterday with it FULL, got home and it was about 1/4 full.  Started it this morning it was about half full.  got to work and it is completely full again.  This one is just weird.
I have checked all my connections and everything is tight, and the bike never has a power loss of any kind.

The idle has stayed around 800 rpms since I adjusted it.

[stereomind]

Maybe the fuel pump is getting lazy?

[Slydynbye]

Isn't 800 rpm too low to get the oil to circulate and the battery to charge?

[dgc67]

The oil should circulate any time the engine as running, though I know on a 1st gen it is not good oil flow to the top until 3000 rpm, but sure can't set my idle that high.  When riding I try to keep it above 3000 always.  And I try to not stay at idle very often. 
No, it does not throw a real charge at idle, even if I had it idle at 1000 rpm it would not.  Not positive, but they usually start to throw a full charge about 2000 rpm.  Again, too high for idle.

Normal idle, from my experiences with bikes, is between 750-1000 rpm.  Most cars idle right at 750 rpm.

[hootmon]

I used to have my Gen3 set to 750RPM at idle and it idled fine, but I read about the lack of oil to the top end. Since I have a '94 that never had the TSB work done, I bumped it up to 1K at idle.
I'm not sure it really helps at all, but does give me a little more piece of mind, so I guess it's working.. 

[L J VFR]

I used to have my Gen3 set to 750RPM at idle and it idled fine, but I read about the lack of oil to the top end. Since I have a '94 that never had the TSB work done, I bumped it up to 1K at idle.
I'm not sure it really helps at all, but does give me a little more piece of mind, so I guess it's working.. 

The service manual states an idle of 1000 rpm + or - 50 rpm on the 3rd gen bike.  I keep mine at 1000 rpm as well.   I think the 3rd gens don't start fully charging until 3000 rpm as well.  Someone correct me if I am wrong.

[lragan]

My understanding is exactly as yours, Lance, on both points.

My '96 idles at 1000 quite nicely.

[dgc67]

Well, mine is going to be set to 1000 today, although I don't think this will have any bearing on oil flow or charging.  I did much more stop and go riding this morning than my typical commute and it died on me a couple of times.  So, I guess the 800 or so rpm is a little to low.

I believe it starts throwing a "full" charge about 2000 rpm and does not vary after that.  Meaning one consistent output no matter how much higher the rpm go.

My fuel issue is still doing this same thing.  Anybody think this could be heat related?  Pressure from expansion in the filter due to heat?
I don't think the fuel pump is stopping any, or slowing down.  The bike is still responsive, so it appears to be getting what it needs to keep the bowls full.  I can't really accelerate and look down at the filter at the same time to verify seeing gas go through and trying it in neutral is not a true test as it takes so little gas to do that.