I need some ideas where to look before i ruin the expensive Plugs I am about to put in.
Here's my story and I am sticking to it.

Some may know my Bike (07 MS) has not run right since new, always had a persistent pop back through carb, dealer refused to touch accelerator pump, But did order a new Jet as mentioned here as "AT Wit's End Backfire cure" http://roadstarclinic.com/content/view/62/96/ Well that never cured it.

Fast FWD, in 10K miles I have had it stall out while pulling into traffic, once I was turning and it tipped over, (Odd I was turning U turn slow left and it tipped right when it stalled) Jacked up my Bag and hand grip (I almost caught it as I learned to expect it to stall.)

I have had it to dealer 10's of times, they refuse to make paperwork on it just take it in lean it out more and see ya. Few times they loaned me a bike for other than adjustments. (I think to cover them on Lemon law)

10K miles now, Pop back through Carb, they never could fix it.

OK, now someone here reminds me of the trick to turn off accelerator pump. I did, it works, no more pop back 99% of time. Runs OK, little weak and rough to me but no pop back.

BUT, It Fouls out 1 & 2 Plugs EVERY morning, Choke functions ok, It don't even matter if you use it or not, I tried not using it, Start, push it in and warm it up with throttle lock, Take off, about 5 blocks it boggs down and two plugs foul, (No matter what you do with choke this still happens, on , off, more, less, none it don't make a difference) if you get it to run with enough power to move it (And BARELY in 1st Gear) you can go like hell and make it finish the trip but have to clean plugs, and replace when ya get back.

Two plugs look perfect according to a plug chart, the rear cylinder (Marked 1&2) are junked up solid black soot and hunks. Every time. I am on 3rd set of plugs this week!

I now have the NGK 5629's on order, (Premium plug for 1700) They are VERY expensive as far as a plug is concerned, Be here in a week. Kinda wonder what the heck is going on.

Once it gets warmed up and going, it runs OK. Meaning will idle and can ride but a little weaker power over what I remember from even 3K miles ago.

It sounds OK at the exhaust.
No Popping to speak of on decel,
No more pop back through carb.
Just kinda acts like it's not burning gas way it should. Yes I cleaned tank and tried several different fuel brands.) Adding Lucas fuel additive seems to make it run better.

To top it off when I spent $340 to put a new tire on, dealer charged me $19 to adjust Pilot Screw 1/4th a turn, So I figure they are not looking at it as warranty any more even though they never even fixed it at all since brand spanking new delivered 7 months ago.

I'm on my own, Yamaha Mechanics don't know crap anyways.

But I am going spark plug broke and my GF is a little pissed I have a new bike her 03 Areo 750 can run circles around all days of the week, and Her's never ever saw the shop.

1st NEW bike I owned and WORST running bike I ever rode!!!! Crap! I had A Maxima with 4 Carbs and in 60K miles never had problem one out of any of them! What gives I can't get ONE to run right.

ALL Stock as I am afraid to add anything.
Replaced filter with K&N because Pop Back was soaking other Air Filters.
I tried 5 different Brands of oil. (Always a WIX Oil Filter)

I'm at wit's end!

MC

FWIW possibly a bad coil or coil wires. If you've changed plugs that much the plugs can be eliminated as a problem. The coils and/or, wires have been known to go bad. Plus they're in an area that's not ventilated real well. You could have a manifold leak which would off set the balance of fuel/air delivery to the cylinders. Find another (trustworthy) dealer in your area. Some members here might be able to recommend one. Have them go over it or suggest potential fixes. M2CTS

Greyphart

Stick a paper towel or something to the rear pipe and see if it sucks it in,it should blow out all the time... and you need to tear into the carb and see what they have the settings at for someone to help you..and you may consider calling Yamma mamma direct and file a complaint ..Coug

Stock bike ... off the showroom floor ... absolutely no mods ..... correct.

I assume that if you start it without the chock then you need to keep the throttle up to keep it running.

In that case I'd check the float level, it could have been set incorrectly at the factory.

It's not the plugs so don't go putting in $$$$ ones ... just buy the cheapies.

Somethings odd with your bike ..... worse comes to worse you need to buy a jet kit and rejet it.

Doc

If it is your back plugs then you have the same problem I had for 8000 miles and that was bad jetting by the dealer. A dealer can't jet one of these bikes because the don't have the time to devote to figuring out what you need. I had a dead rear cylinder at 3000 miles. They said the rear plugs were fouled and put new ones in and even charged me. I took it back 4 times after that between 8000 miles. Finaly I got rid of my SVS which is what you will have if it keeps up. I rejetted the bike myself with a lot of trial and error work and finally got it right. Everyone used to joke about me and my carb. I got to where I can rejet all the jets and change the needle in 15 minutes. I am now over 21000 miles and haven't touched the carb sense I got it right at 8000 miles. Your wasting your money trying to get a dealer to do it. Find a good independent shop with a dyno and have them jet it if you can't do it. That way you get it right first time around and save a lot of money.

All good suggestions to check
Dig into the Tech Articles and see if you feel like you want to troubleshoot it yourself
is the warrenty only as good as the dealers mechanic?
once found and fixed you will not be disappointed with the bike.
I lean towards an air leak in or around the manifold, and possibly the carb has been adjusted to compensate somewhat.
just a guess

Sounds to me like an air leak on the front cylinder and the carb has been rejetted to compensate for the extra air flow. Except the rear cylinder isn't getting all that extra air so the extra fuel doesn't get burned, hence the fouled plugs. If you pull the tank and rig up a temporary source of fuel so you can start the engine, shine a light on the intake and spray a little carb cleaner on and around the intake and watch to see if it gets pulled into a crack or around the intake flange. The problem has got to be on the front cylinder.

Yea all responses are making sense and making me think.

I did do AIS removal, forgot to mention, but I do hear like air sometimes mostly when cold had me looking at the plugs to see if they were sealed.

Dealer did SAY they replaced the manifold, this was their 1st fix, said it was leaking.

They really might have just Jetted it to compensate. (I'll be pissed!)

I will like the bike when I get it running right, Nut I am really pissed I spent the money on a new one so I would not have to work on it so much and it BACKFIRED! Pun intended.

On the read now, when I go home I'll check some of this stuff out. Parts man at dealer slipped me Yamaha's CS number, I'm calling them on Monday.

But keep the ideas flowing. Helps me think.

So Far the YES warranty means no.

I think stinger is right on the money. That just makes sense. Is your mileage/months of ownership past the warranty limit?

The Update,
I pretty much thoroughly checked everything mentioned and then some, I did go with the better spark plugs, that along with shutting down (As in total off) accelerator pump, cured the plugs from fouling every time I started out cold. BUT it still runs like crap, more crap when cold and then intermittent crap throughout the day. I concentrated on the Intake leaking but it seems that if it is, it's an intermittent leak. I used SEVERAL ways to determine a leak with no leak detected. So While at the dealer I gave em one last chance to fix it before i called CS. Dealer pointed out I should not have been charged $19 for the 1/4 turn of PMS and bring it back we'll fix it. So, It's back! I know they ordered a new intake. (This would be 3rd one on my bike) I just hope they fix it, I would really love to ride a RS that runs right.

On my way to work, I realize how dangerous autos are, that thing has blind spots! (But I do feel a little more protected, even without a helmet.

MC