Starving for fuel

[heavyd]

Now that my final drive is all back together, I have been trying to get some miles on locally before I go on any long trips. Went on the Ride For Dad yesterday,and then a 150km cruise afterwards. I didn't notice on the Ride, but when I was cruising some backroads later in the day I started noticing between 90-100km/h 2200-2700 rpm it is stumbling a little. It feels like it is starving for fuel, the same hesitation that I get about a minute before I have to switch to reserve. I am hoping to pull the plugs tonight to have a look since I just changed them when the final drive was apart and I realized I am not sure how they should look. When I took the old plugs out, they were fairly dark brown and a bit wet but that was after changing my antifreeze so the bike only ran for 4-5 minutes to get the air out. Not sure if that is a factor, but it was choked at first because it hadn't been running for 3 weeks, then just sitting at an idle.

I guess this was a long way of asking if someone could post a pic of the way my plugs should look? Thanks

[YoungPUP]

You want your plugs to look like lightly browned toast.  2500ish RPM is where mine was having problems when the slow jets were starting to get crapped up.  IF shes been sitting a while for maint. I'd try a can of seafoam (or pour in fuel system cleaner of your choice) and run that tank through and see if it improves.

[Patrick]

Have you had the fuel off ?? If so, then check to make sure the vent line isn't kinked [common thing]..

If you have a vacuum operated fuel valve then it could be starting to have problems [ another common thing]..

Any continuos driveability issues below 2500 rpms are usually varnished low jets.. A good dose of Sea-foam before the problem becomes too serious usually helps...

[Chrisj CMA]

Dont even worry about them plugs......its your petcock, or vacuum system if you havent desmogged.  Check the two vacuum lines that go to the middle intakes on each side, carefully look at the caps for unused nipples and the main vacuum cause for petcock malfunctions....the long line going from #6 to the petcock....if that is cracked youre in luck its the easist to change

[Ricky-D]

Here ya go.

http://www.centuryperformance.com/spark-plug-reading-spg-192.html

***

[heavyd]

Thanks for the info everyone, I am always amazed at how fast and reliable the responses are on here. I usually run a half a can of seafoam through every 3-4 tanks, I have about 1/3 of a tank right now, maybe I should dump a whole can in? The fuel tank/petcock haven't been touched in at least 4-5 years, don't think anything has moved to kink any fuel lines. I have been wondering about the slow jets for awhile but I haven't wanted to touch the carbs due to my very limited mechanical ability, and lack of Valkyrie mechanics on PEI to fix a mistake.

I haven't desmogged, but I looked at my vacuum tubes in the spring as a possible source of my popping on decel and everything looked fine then. I have new redeye caps and intake orings on the way, but not sure when they will arrive. Am I likely to damage anything driving it as is?

Thanks

[Chrisj CMA]

The only think likely to be damaged is your fuel consumption (mpg)  The vacuum lines to #3,#4 are darned near impossible to inspect wihtot removing them.  

With the bike running, try to have an ear down by the intakes and gently blip the throttle and listen for whistling, you can also spray carb cleaner gently under the carbs....if idle increases when you spray then you have vacuum leaks.

I more strongly suspect a detrriorating petcock.

[Russell Rice]

I would check all the vacuum lines before I started tearing anything apart.

[heavyd]

The only think likely to be damaged is your fuel consumption (mpg)  

Strangely enough, my MPG sucked earlier in the spring and I attributed it to the cold temp because my last ride last year was to lead my fathers funeral procession and I burned approx 7L in 40km. It was the 5th of December and 3C. Since this started yesterday my MPG is back to where it should be, haven't ran it to reserve but by my math I should hit reserve around 220km riding 2 up.

[heavyd]

Issue is still there off and on. New O-rings and vacuum caps arrived today, so hopefully that will solve it

[heavyd]

Finally got the vac caps on a couple of days ago, they were hard and cracked, but were only part of the problem. My number 3 vac line has finally gotten bad enough I can see an issue. Going to tear things apart after my Fathers Memorial ride next weekend, don't want to risk something going wrong. Gas milage isn't great, but everything seems to be working fine other than a little stumbling. And once I am over 120km/h it works flawless. 

Any advise on the vac line replacement? Been reading all the info I can find on it, and planning to replace the air filter and intake o-rings while I am in there. 6ft of 5/32" ID silicon tubing should do it right?

[Chrisj CMA]

Use the string method (search for it) and you dont have to remove the carbs or the airbox

[X Ring]

Finally got the vac caps on a couple of days ago, they were hard and cracked, but were only part of the problem. My number 3 vac line has finally gotten bad enough I can see an issue. Going to tear things apart after my Fathers Memorial ride next weekend, don't want to risk something going wrong. Gas milage isn't great, but everything seems to be working fine other than a little stumbling. And once I am over 120km/h it works flawless. 

Any advise on the vac line replacement? Been reading all the info I can find on it, and planning to replace the air filter and intake o-rings while I am in there. 6ft of 5/32" ID silicon tubing should do it right?

Here's your solution  http://www.valkyrieriders.com/shoptalk/desmog.htm

Marty

[heavyd]

Thanks ChrisJ, I thought about that because it does look a lot easier but I think I am going to do it the hard way. lol. Gives me a chance to learn a little more about the bike and how it goes together, and I can change the air filter while I am in there. I also have new intake o-rings so I might as well do it all at once.

Marty I thought about that, but I haven't read about any advantages to desmogging other than no more popping or vacuum leaks. The popping doesn't bother me that much and if the new lines last the 15 years that the originals did that seems like a better option the tearing all that tubing and stuff out. IMHO. Am I missing some advantages? Still on a steep learning curve here.....

Thanks

[BradValk48237]

I would say that you need to check the Diaphragm on the pet rooster...

I have had this happen 2 times and now looks like a 3rd... main symptoms are fuel starving issues... It dosen't just up and quit.. at least for me it didnt.... sometimes it would run fine and them you'd be going down the road and it would run out of fuel.... then wait a couple of minutes and you could go again....

I think that the diaphragm gets a tiny leak/crack and pressure from the weight of a full tank helps keep it open and more vacuum from higher RPMS... as the tank gets lower, less hydraulic pressure and the valve closes..... if I switched to reserve then the bike would run again until the level in the tank got lower.. As soon as you slowed down the bike would stumble and some times almost run out of fuel or would run out

I am thinking of just moding my stock petcock to manual only as I don't have $90+ bucks right now to get a Pingle that would do the same thing...

I'll bet its the petcock diaphragm....

Just my 2 cents..

Brad