Bike not running right.

[Pighuntingpuppy]

The 2007 has got something going on. Finally got the coil out as the weather finally played nice out. Quick back ground on whats going on. Bike starts normal. Will normally go through the gears without a hiccup. No misfires or stumbles. When you lay into the bike and get it into Vboost, it feels like its just lacking on the top end. It never breaks up. It never stalls. Fuel mileage is higher than normal. Normally around 30-33mpg. Last couple tanks, I am nearing 40mpg. Even giving it hell. One other thing I noticed. When the bike is at idle, the RPM is 900. Normally when it is operating temperature, it is 1000 RPM. I removed the air box, checked the slides and top air jets. Nothing seemingly out of place. Removed the spark plugs. The right front spark plug is fouled black. Remaining 3 are light tan. So....despite the lack of raw fuel smell and higher than normal fuel mileage, I removed the ignition coil. Since this is what I suspect at the moment. Tested the primary coil. 3.2 ohms. Specification is 2.7 ohms. I will take this as an acceptable reading as temperature may not be exactly as the manual states. The secondary resistance is 13.17 K ohms. Specification is 13.2 K ohms. Again, I will take this as an acceptable reading as temperature may not be exactly as the manual states.

I may be overlooking something as generally when I see something that looks off, I can usually determine if its fuel or spark. I black spark plug tells me that I am getting either too much fuel or not enough spark. Since my fuel economy has increased....at this second, I would tend to overlook the carbs as the guilty party. But I know it could be. Same thing with the ignition coils. They may be the guilty party.

These are the symptoms, which is what I detected from this particular point. Spark plugs were installed earlier this year with NGKs. The Yamaha dealer did a valve adjust and carb sync less than 18 months ago. I know these mean squat in the grand scheme of things but its the history I know. What would be the next course of action to look at?

 

[Parminio]

I think you need a carb rebuild and thorough cleaning. My opinion is that you just have a bit of corrosion and the like around the jets that's just slowing down the fuel flow a bit.

On a personal note, I wish I could get 40 MPG out of my 07. I'm lucky to get 30 when I give it hell.

 

[Pighuntingpuppy]

The question is....would that fuel foul spark plugs? A restriction in fuel? See I work on cars for a living. Black plugs means someone is running rich or no spark. I agree that lack of fuel would account for an increase in fuel mileage. But it is contradicting what the spark plugs are telling me. Thats why this scenario is making no sense to me.

The 40mpg is happening now due to the condition it has. See where I live, I have long open roads. I can hit 100 and drive it till I run out of fuel. And at those speeds I can get 30mpg. Its the stop and give it hell goes that eat up gas mileage. Its like the Gen 2 mileage. I read that people are getting high 20s with it. I am getting low 30s with mine. 100-105 miles is 3 gallons of gas. When the fuel light kicks on. Those sustained speeds even you out. My Silverado, gets between 14-19mpg. 2004 6.0 with 4x4. Towing I was averaging 13. Same thing. Long open roads, fuel mileage even outs. When I play in the city though. Single digits. This last bit has nothing to do with the bikes problem, just an anecdote of what fuel mileage means.

 

[Parminio]

It may be oil fouled and not fuel fouled. You should be able to smell the difference with ease.

But if it's fuel fouled, you don't get better mileage by running rich, so that's a non-starter. You shouldn't get better mileage by not firing on one cylinder either because you're going to me moving the same amount of gas no matter what.

And as I mentioned elsewhere, take the plug out, hook it back up to the wire, start the bike and see if it's firing properly. If it is, that's not the problem.

At the end of the day though, problems don't net you better mileage except for one that I can think of: restricted fuel flow.

A Gen 1 Vmax will average around 30 MPH no matter what if it's stock and running right. I think the most I ever got out of mine was 34.

 

[Fire-medic]

I'm in-line on it being some obstruction or deficiency in the carbs. Time to remove 'em and to clean/inspect 'em.

 

[Pighuntingpuppy]

It may be oil fouled and not fuel fouled. You should be able to smell the difference with ease.

I dont think its oil. I havent lost any. Oil is still right where it was when I last changed it about 2000 miles ago. This looks fuel fouled. Oil fouled plus will either look ashy(if ran long enough with a light to moderate burn). Or they will get a wet look that does not dry(during a heavy burn). My 1988 truck before I built the engine, was sucking oil on the #1 cylinder. When it would completely foul out, I would get a dead cylinder(engine misfire) it would have a gummy wet look to it. I kept a stock of plugs in the truck cause it at first it seemed every 1000 miles or so and progressively got worse till the cylinder was completely cooked.

As for fuel, it very well may be. Right now, I am looking for suggestions that may be more evident as others. Diagnosis right now is cheap. Shotgunning parts is not. I am not committed to replacing anything yet. I have not yet been able to get the carbs off yet. Lost the light again while I was checking other things. When I get some more time and light, I will pull those carbs and check to see if I have a piece of debris blocking something. My first thought was the needle wasnt pulling out of the mains. Cause the problem seems to happen under high RPM under load and Vboost. Round town driving....you would never know there was anything wrong with the bike. Gets up and go. If you keep out of the Vboost, you can hit 100-110 with no problem. Thats why I checked the slides to see if they were pulling out with the engine running. To see if there was any fluff or debris evident with a basic visual inspection.

Once I get the carbs off and apart, I will let you know what I see and find. Maybe something obvious once apart.

Thanks for the help so far.

 

[Fire-medic]

Look for Damon's video on ebay for going through your carbs, or we have multiple members on here who can rehabilitate them for you. That would be dannymax (see the banner ad), CaptainKyle, or Sean Morley.

 

[redbaron13]

Sometimes the screw will come out of the main tube and you will pull the main fuel jet out of the carb into the throat . easy check, putll the airbox and operate the throttle back and forth to see if it is moving. if it is, pull the float bowl cover, push the jet in with your fiinger and tighten the screw. You do not have to break the carb rack, just use a flex extension and a japanese bit, not a standard. Low battery will fowl plugs. Bad fuel pump may affect bad top end running. I pulled that junk fuel pump out and put in a mr gasket green model, same psi as the oem pump. Still have not had a problem. Sometimes, if a po is not careful and he adjusts the vboost, he may not tighten the cable enough, this will keep the boost from fully opening, as with the screw falling out of the thing, then just the cable pulls and does not open the boost. But I do not believe you can see the screw without removing the carb rack. Other problems can lie in the cricuit card. Mine quit cycling randomly, pull the controller cover and push on the transistors while cycling the key, mine would only cycle with pressure on the oem card. Instead of buying the expensive oem controller, I put in a galaxy controller with the dip switches in the oem position. If that sucker goes, and I cannot find another there is a guy on the net that rebuilds the controllers for about 450 bucks. Or Sean may have some of those. In 5.5 years of riding, I did the wiring harness crimp mod, replalced the starter clutch, ecu, vodoo exhausts and the fuel pump mod. Those cheap connectors melt too coming out of the left side gear cover going to the connector. I broke that crap off and hard soldered the wires together with insulation of course. Since the I have just been riding the thing, minus about three months for a hip replacement. There is a lot of other stuff that can go wrong after reading through the tech data here, but this has been my limited experience with the bike, I crank it, let it warm up, and ride it like I stole it.

 

[redbaron13]

oh, I forgot the voodoo exhaust two into one, freaking love it, the deer will not run in front of me. They just look and by that time I am gone.

 

[redbaron13]

Woops, clutch slave cylinder, They seem not to salvage well.

 

[Fire-medic]

Woops, clutch slave cylinder, They seem not to salvage well.

I prefer to replace with OEM NOS dealer-available things like the master cylinders and the clutch slave cylinder.

 

[Screwloose]

The 2007 has got something going on. Finally got the coil out as the weather finally played nice out. Quick back ground on whats going on. Bike starts normal. Will normally go through the gears without a hiccup. No misfires or stumbles. When you lay into the bike and get it into Vboost, it feels like its just lacking on the top end. It never breaks up. It never stalls. Fuel mileage is higher than normal. Normally around 30-33mpg. Last couple tanks, I am nearing 40mpg. Even giving it hell. One other thing I noticed. When the bike is at idle, the RPM is 900. Normally when it is operating temperature, it is 1000 RPM. I removed the air box, checked the slides and top air jets. Nothing seemingly out of place. Removed the spark plugs. The right front spark plug is fouled black. Remaining 3 are light tan. So....despite the lack of raw fuel smell and higher than normal fuel mileage, I removed the ignition coil. Since this is what I suspect at the moment. Tested the primary coil. 3.2 ohms. Specification is 2.7 ohms. I will take this as an acceptable reading as temperature may not be exactly as the manual states. The secondary resistance is 13.17 K ohms. Specification is 13.2 K ohms. Again, I will take this as an acceptable reading as temperature may not be exactly as the manual states.

I may be overlooking something as generally when I see something that looks off, I can usually determine if its fuel or spark. I black spark plug tells me that I am getting either too much fuel or not enough spark. Since my fuel economy has increased....at this second, I would tend to overlook the carbs as the guilty party. But I know it could be. Same thing with the ignition coils. They may be the guilty party.

These are the symptoms, which is what I detected from this particular point. Spark plugs were installed earlier this year with NGKs. The Yamaha dealer did a valve adjust and carb sync less than 18 months ago. I know these mean squat in the grand scheme of things but its the history I know. What would be the next course of action to look at?

Just as an aside for anyone that is unaware. When using an Ohm meter, before taking a reading touch ur probes together and that determines the leads resistance, this leads reading is taken away from ur test reading and is normally very low (0.1 Ohms), but also checks ur sometimes very old leads, and hence false readings especially if u do not use ur meter and leads very often. Its a cheap calibration method.

 

[Pighuntingpuppy]

Just as an aside for anyone that is unaware. When using an Ohm meter, before taking a reading touch ur probes together and that determines the leads resistance, this leads reading is taken away from ur test reading and is normally very low (0.1 Ohms), but also checks ur sometimes very old leads, and hence false readings especially if u do not use ur meter and leads very often. Its a cheap calibration method.

Yup. I have been burned by bad meters and leads before. I have 3 different meters. Fluke is what I used for this testing.

I still havent been able to get the carbs off yet. Life and such in the way and when I get home, I am out of ambition for the day aside from eating showering and taking it easy for the night before getting back to it. I will get the carbs off probably this weekend if the weather holds good and report back what I find.

 

[Screwloose]

I know the feeling, setting up these carbs grinds u down with limited time. The info on this site compounded on my own carb knowledge. I’m still crackling and popping on initial choke startup being lean from float height, and i’ve had the carbs out at least 5 times, its for sure the only bike I would do this with, and i’m 59 and had many motorcycles. Perseverance , stuberness pig-headnesess, determination are in my view the pre-requisites of VMax G1 ownership, ermm forgot to add proud ownership of superior knowledge of motorcycles in the pub.

 

[LouisCurtis]

I know the feeling, setting up these carbs grinds u down with limited time. The info on this site compounded on my own carb knowledge. I’m still crackling and popping on initial choke startup being lean from float height, and i’ve had the carbs out at least 5 times, its for sure the only bike I would do this with, and i’m 59 and had many motorcycles. Perseverance , stuberness pig-headnesess, determination are in my view the pre-requisites of VMax G1 ownership, ermm forgot to add proud ownership of superior knowledge of motorcycles in the pub.

I think you're right about this.

 

[Pighuntingpuppy]

Alright, got the carbs off today. I know some folks said I didnt need to break apart the carbs. But I figure if I have them apart, I am gonna see what the failure is. Once disassembled, noticed absolutely nothing. Not a fleck of sand. Not a blemish of varnish. All holes blow through clean and free. Springs appear to be doing what they should. Attached are some pics. If anything stands out in the pics or if you want a different perspective of pics, let me know. Right now, I am back to leaning toward a weak spark. Any ideas welcomed.

Edit: these pics were taken before the brake clean spray through.

 

[Fire-medic]

Did you remove the brass jets from the jet blocks?

 

[Pighuntingpuppy]

Yes. Just the two. The plug, I left alone. Dont got the tools to go messing around in there. They were squeaky clean as the rest of the carb. No corrosion. No varnish. No rust or sand. The Vulcan I acquired.....When I cleaned those carbs....there was noticeable contamination. The results from a dirty set of carbs to clean set of carbs was night and day. If there is something with the carb, its not noticeable. Or I just am not seeing whats wrong. Either or. But right now, I am leaning toward a spark issue. But before I reassemble the carbs, I wanna make sure I am not overlooking something. Since the weather is turning here, there is no rush to get the bike back together right this second and I have the Gen 2 to play with if weather does play nice. So, slow and steady is the pace and diagnosis is cheap at this moment. So any direction I get will be followed through to the T.

 

[02GF74]

When you say the jets were clean, that means the tiny hole going through them was clear?

When I did mine, I did not have the right tool so used a strand of copper wire from an electrical cable, nipped many times on the sides with a pair of wire cutters to make it like a file, to clean out dried up gunge.

 

[Fire-medic]

When you say the jets were clean, that means the tiny hole going through them was clear?

When I did mine, I did not have the right tool so used a strand of copper wire from an electrical cable, nipped many times on the sides with a pair of wire cutters to make it like a file, to clean out dried up gunge.

Some people use the acetylene tip cleaner wire sets, I have a single-strand stainless-steel wire I use for this. The knurled-surface they machine onto the acetylene tip cleaner steel wires could change the I.D. of your softer brass jet, if you choose the wrong one, and use it like a drill.

I don't think there's any need to remove the brass plug in the jet block.