Decreased gas mileage & horsepower.

[F6Ghostrider VRCC #32501]

Iv'e been noticing decreased horsepower over the last year. Initially I wrote it off as an exhaust leak which progressively worsened over time. One day last July, I acquired a set of OEM pipes. All the numbers were exactly the same as on the pipes on my 99 Tourer so I wasn't concerned about a pipe swap. By the way, they were so new there was no residue in the manifold or the piggies.

After the swap, my exhaust leak is completely gone, but now my mileage has decreased from 36 MPG down to 18 - 19 mpg . The engine runs as if I am running in 1 or 2 gears too high. From a dead stop, I really have to apply more throttle and slip the clutch. Iv'e been thinking the slow jets may need some TLC as she now has 154,000 miles. Iv'e done pinion cup, shaft replacement, rear wheel bearings & numerous front and rear tire replacements, but pulling the carb bank scares the bejeebers out of me. I know there are numerous posts with great results from some who questioned their own abilities, but I still am apprehensive. Pulling the tank is such a PITA. I hate spilling gas!
I hope that no one else has experienced this, but I'm sure someone may have good direction for me. Additionally, I hope I have provided sufficient information for a somewhat accurate diagnosis.

Thanks for everyone's help.

Jeff.   

[R J]

Are you sure the choke isn't on FULL?

The lever may move, but look down on the right side and see if the shaft is retracting.

Is it kicking BLACK smoke out the pipes?

[Pete]

If mileage went from 3X to 1X mpg just after an exhaust change?
Sounds like a stopped up exhaust.
Or a very bad mismatch between exhaust and carb settings/tuning.

[salty1]

How does the bike idle? Does the bike run smooth through all the gears, even though it lacks power? Have you checked for any vacuum and  intake leaks. When is the last time the air cleaner was serviced?

[Gryphon Rider]

Yup, take the tank off.  First check for a clogged air cleaner, then inspect all your vacuum hoses.  What do your spark plugs look like?

[Bighead]

This has nothing to do with your mileage but you shouldn't be spilling gas by removing the gas tank unless the Petcock is bad.

[sandy]

Why did you swap pipes if they were the same? Do the new pipes sound any louder/quieter than the originals. If they're quieter, then you probably have rejetted carbs and it's too rich. Run a half a can of Seafoam in a full tank.

[hubcapsc]

This has nothing to do with your mileage but you shouldn't be spilling gas by removing the gas tank unless the Petcock is bad.

I'm not sure what happened to the OP, but if you set your tank "on its nose" gas will
probably start siphoning out of the vent pipe at the rear of the tank...

-Mike

[Bighead]

I have had my tank off numerous times almost full and never spilled a drop. But I did keep the tank level when sitting it down and such would make much sense to tip it in my opinion

[Hook#3287]

Pulling the tank is such a PITA

Wait till you get to the air box

Really, if you did a rear wheel service, you can do the carbs.

Are you the original owner?   What's the history on the exhaust system?

Your carbs may have been re-jetted if you had aftermarket or modified exhaust.

[bassman]

M'be try putting the old pipes back on.....perhaps in the process of the swap you may have tightened up something on the new pipe install that had loosened on the old pipes and not noticed before?

[F6Ghostrider VRCC #32501]

I thought I might overlook some important details. Just didn't want to admit it. I am a member of the OTHG!
Original pipes all broke loose where they fit into the muffler. All 6 pipes broke away from where they were fit into the mufflers. Anybody have a fix for that? can the mufflers be cut and the pipes reattached?Too many wedges to get clearance to remove back wheel. I probably was doing it wrong.
My choke is off. No black smoke.
I'm the 2nd owner. Dad's not around to ask about jetting. But I'm pretty sure carbs are unmolested. Although I do believe the bike has been de-smogged.
The new OEM pipes have identical#'s as the old pipes. They sound really good. It lacks power under a load. IE; shifting through the gears.
And to answer the 64,000 question, I have run GALLONS of Seafoam and Berryman's through the fuel system with negative results. EVER!
Now that I think about it, I do have a K&N and it's probably been about 20,000 miles since the last cleaning.
And to answer the ?, prior to installation, I was able to push air through each pipe with a small air compressor with no blockage.
Kind of embarrassed. I am so good with my PM. Can't believe I overlooked the air cleaner. Next RDO's are Sat/Sun. 8 days straight.  If Momma doesn't have me gaffled up, I'll clean the air filter.
I'll keep you posted.
Many thanks fellow Valkaholics

[Bone]

When I ran K&N filters in other vehicles cleaning was not recommended at short intervals, 20k miles is a short interval for the K&N's.

[Punisher]

Check your vacuum sliders (diaphragms) under the carb covers for holes/tears.   This was recently found on another member's bike and it was causing a big loss of power and bad fuel mileage.

Be careful pulling them and then hold them up to a light to look for pin holes/tears.   Be careful putting them back in as well, make sure they are correctly installed.

To narrow down which cylinder(s)  may be impacted you can pull the plugs and look for a lot of black soot on them.

[Rio Wil]

So, since you have been loosing power over the last year, what is the answer to this previously asked question?

How does the bike idle? Does the bike run smooth through all the gears, even though it lacks power?

[F6Ghostrider VRCC #32501]

The bike idles smooth and upon reaching normal operating temp, the idle is about 900+. It runs smoothly through the gears. It just lacks the HP when under a load. Definitely worth pulling the plugs and even looking at the diaphragms.

[Punisher]

The bike idles smooth and upon reaching normal operating temp, the idle is about 900+. It runs smoothly through the gears. It just lacks the HP when under a load. Definitely worth pulling the plugs and even looking at the diaphragms.

Same symptoms the other bike had.   Does your bike smell like it's running rich?    The other bike wasn't smoking out of the exhaust at all but was very rich smelling while idling or going down the road.

[F6Ghostrider VRCC #32501]

Now that you mention it, it does smell rich. I couldn't put my finger on it, but that is precisely what  smell.

Now that is identified, what should my plan of attack be?

It used to be hard to start. Crank & crank & crank & finally would start. I washed the springs off with brake cleaner, lubed the cables and tightened the clamps on the carb boots. Really helped tremendously. Starts right up. Still spills a little fuel on the ground upon starting.

[Punisher]

Now that you mention it, it does smell rich. I couldn't put my finger on it, but that is precisely what  smell.

Now that is identified, what should my plan of attack be?

It used to be hard to start. Crank & crank & crank & finally would start. I washed the springs off with brake cleaner, lubed the cables and tightened the clamps on the carb boots. Really helped tremendously. Starts right up. Still spills a little fuel on the ground upon starting.

Pull the plugs and see if any exhibit sighs of running too rich.    If one or more appear that way then pull those vacuum sliders and hold them up to a light looking for pin holes or tears.   Be careful with them and make sure you put them back in properly.

[Ricky-D]

Along with all the other suggestions, probably a wise decision

would be to perform a compression test on the engine in

order to ascertain the condition of the engine.

***

[DK]

I would consider changing the oil if gas has been dripping from exhaust. If above the mark when checking oil The oil, any extra would be gas thinning the oil. Not good.

[F6Ghostrider VRCC #32501]

Upon starting, it spills maybe 3-4 tbsps of fuel. But not from the exhaust. Drips near the center. And only after it sits overnight.

[Ricky-D]

Upon starting, it spills maybe 3-4 tbsps of fuel. But not from the exhaust. Drips near the center. And only after it sits overnight.

It sounds to me that you have a serious problem that

needs immediate attention.

***

[salty1]

Upon starting, it spills maybe 3-4 tbsps of fuel. But not from the exhaust. Drips near the center. And only after it sits overnight.

It sounds to me that you have a serious problem that

needs immediate attention.

***

  This could be a fireball if your not careful. Time to teardown and rebuild your carbs.  ???

[pancho]

I agree with the two previous posts,,, I would not take a ride on the bike until the problem with spilling gas is isolated and repaired.......    spilling gas is pretty serious stuff!!! 

Is the fuel coming from a tube under the bike or spilling on the motor??  If it is a carburetor spilling from the overflow, you may be able to clear the needle valve by tapping on the carb,, if this is the case, there are other serious problems this can set you up for other than fire...... which is pretty serious by itself.

[F6Ghostrider VRCC #32501]

Definitely not spilling on the engine. There is never anyone around at 0445 to tell me exactly where or which tube the gas is coming from.
Funny thing though; although not really funny, is that when I started riding this bike after my Dad passed 6 years ago, it has always spilled a little gas. Don't know if that was an issue he didn't get around to fixing, or it started when I started riding it. It did sit for six months prior.
Guess Ill bite the bullet and rebuild the carbs when it starts raining here next month. 

[Ricky-D]

My impression to that post:

Gonna use a sledge hammer to swat that fly.

Evidently, thorough investigation is "off the

table" due to the lack of another set of eyes.

***

[BudMan]

If you have a normal drain set-up, all the carb overflow tubes empty into one common drain tube below the bike. I would take individual tubes and run them from each carb to individual “Dixie” cups below the bike. This would allow you to know which carb needed immediate attention.
I have removed my bowls, floats and jets before without taking the carbs completely out of the motor. I just took off the air box and upper connections, removed the intake runners and raised the carb bank first on one side and then the other. With the carb bank raised up as high as it will go in that position it is easy to get to the underside of the carbs for most work.
(This is a lot harder to describe than it is to do!)

Keep us posted!

[The emperor has no clothes]

If you have a normal drain set-up, all the carb overflow tubes empty into one common drain tube below the bike. I would take individual tubes and run them from each carb to individual “Dixie” cups below the bike. This would allow you to know which carb needed immediate attention.
I have removed my bowls, floats and jets before without taking the carbs completely out of the motor. I just took off the air box and upper connections, removed the intake runners and raised the carb bank first on one side and then the other. With the carb bank raised up as high as it will go in that position it is easy to get to the underside of the carbs for most work.
(This is a lot harder to describe than it is to do!)

Keep us posted!

Seems like once you've got that far it's not much more to just take the carbs out.

[BudMan]

Seems like once you've got that far it's not much more to just take the carbs out.
[/quote]
Linkage scares me.

[The emperor has no clothes]

Seems like once you've got that far it's not much more to just take the carbs out.

Linkage scares me.
[/quote]Yeah I can understand that. I did my standard carbs recently and was worried about getting the linkage back correct. Took lots of pics. But it really was no big deal at all. Didn't even need the pics. It's a lot easier to clean the carbs up on the bench.

[F6Ghostrider VRCC #32501]

Man, I really appreciate everyone's feedback here. A pleathera of knowledge. Most of which I assume came the school of hard knocks. I really think the main problem here is a loose nut behind the wheel.  Probably just over thinking the whole thing. I have a tendency to be uumm..... frugal. Yeah, that's it, frugal.  Guess I'm scared ill drop 500 bones to rebuild the carbs and I just don't have it right now.  If I could get by with jets, bowl gaskets and intake o-rings, I'm there! Thanks a million guys. I'll keep you posted with results as I have an uninterrupted day to invest in troubleshooting.

[f-Stop]

I had very similar symptoms you described while riding home from InZane in 2010.  It started in Wisconsin and progressively got worse as I traveled south through the states.  Power loss and decreased fuel mileage.  I attributed my problem to accidentally filling up with ethanol at a gas station somewhere in Wisconsin and maybe this had gummed up the carbs somehow.  The worst was riding into a big headwind in Kansas where I could only maintain speed while drafting on other vehicles and only getting 15mpg.

So, long story short…my problem was ultimately vacuum lines and cover set.  (Was it the ethanol?  Maybe, but I think the ethanol acted as an indicator.)  I also replaced the fuel lines.  Now, given that you may have the de-smog mod, you probably still have an OEM petcock.  My suggestion would be to replace the cover set and the #6 vacuum hose.  Check or replace all your manifold plugs and replace the fuel lines.  I'd also pull the carb bowls to check your floats, clean your jets and then replace the bowl o-rings.

Now, at 154,000 miles, I'd say that a carb rebuild is not on the whole unwarranted.  But, if you get into it and find that your o-rings in the joint sets are bad and stuff like that…well then ya gotta do it!

Good luck!

 

[97Valk_CT_Euless]

Just ordered all the rubber from Redeye except for the diaphragms.  Was about $120.
Haven't gotten them yet but they shipped them same day.

[F6Ghostrider VRCC #32501]

OK. I am only a mechanic out of necessity. My lingo and verbiage is not where I would like it to be.
So with that being said, "What is the cover set and the o-rings in the joint set?

[Bone]

Here is a picture of the cover set the part number might have changed.
Also a picture of the inside of a petcock.

[F6Ghostrider VRCC #32501]

OK. Now I know what the Cover Set is. What is/does the Joint Set O-Ring(s) look like/do, and where are they located?

[The emperor has no clothes]

OK. Now I know what the Cover Set is. What is/does the Joint Set O-Ring(s) look like/do, and where are they located?

Thats probably the o-rings that are on the bottom of your chrome intake manifolds   it also could be the o rings on the rear wheel. There are 6 of the intake all the same size, and 3 on the wheel of different sizes.

[F6Ghostrider VRCC #32501]

Well, I just replaced the 3 O-Rings in the Final Drive. A for sure, must do every time you pull the back wheel even though it cost me $20!  Didn't do that the last time & had nasty moly crud slung every where!

So, the Intake O-Rings sounds right. That was in my game plan anyway

[Rocketman]

Does your power problem change at different RPM ranges?  i.e., is it low on power at low RPM, but get better once you get into the higher ranges?

Also, I expect that the "rich running smell" is not reliable until you get that fuel leak resolved.

Mark