Jetting - A new one, I think...

[diggerzmound]

I have an 06 that i just put a set of Jardine slip on pipes on. I am at 2500 feet.

With the stock pipes on it seemed lean at idle until fully warmed up, it wanted choke until the temp gauge was almost half way, after warm it would run almost flawlessly. It had a stumble off idle until the bike was fully warmed up.

Now with the Jardine pipes it acts really lean, when idling, if you burp the throttle it is slow to come back down to idle. I ran the pilot screws out 2.5 turns from lightly seated. After this adjustment I had to crank on the idle screw as the bike would just up and die. After adjusting the idle up it still is slow to fall back to idle, and if I engage the choke when the engine is warm it runs up to 4000 RPM's. This all sounds lean to me?

I searched through the carb section and seems everyone says that with slip on s I shouldn't need a jetting change.

I was thinking I was lean, is there something else that could be causing this? I checked all the carb boot clamps and they are all tight and the boots are in good shape.

Any ideas? The bike has 200 miles on it.. I am running fresh fuel. It runs fine on the top end..

If I go with the jet kit, should I go Stage 1 or just jump right in to the Morleys or the Stage7 ?

Thanks in advance

 

[maleko89]

Having the bike on choke until 1/2 way on temp. gauge with your stock exhaust isn't normal. I take my choke off within 2-3 minutes. If your temp. needle is at the first mark it should definitely be fine w/o choke.

To me, it sounds like a clogged pilot fuel jet. I worked on an '06 last year and it had the exact problem except worse. It wouldn't idle at all w/o choke and when it did we had to keep it above 4000 rpms. I would try running a few ounces of Seafoam in your gas tank. If that doesn't work, then the peashooter may work. Go here for specifics on that: http://home.comcast.net/~onlyone12/carbs1.htm

Otherwise, it might be best to dissassemble the carb float bowls, remove the jet block and clean the PFJ's directly. You could take your carb rack off and go to a Yamaha shop that has one of those vibrating carb cleaners. I hear they work well.

 

[diggerzmound]

I don't suppose the dealer will step up and do any of this for me. I cleaned the pilot circuit tonight and it didn't get much better. I pulled the airbox and the slides and shot cleaner through the whole deal with the pilot screws removed. I might try the seafoam.

I put the stock pipes back on (PITA) thinkin i was running lean because of them, and the same crap. This might be a good time for a jet kit.

How hard is it to get those carbs out of there?

 

[maleko89]

It's pretty easy. Just loosen the top clamps of the carb boots. Disconnect throttle cables at junction under left scoop and disconnect the fuel line that goes to the carbs. Pull up out of the boots....it may take quite a bit of tugging. Try to pull up on one carb at a time. Pull carbs out left side.

 

[diggerzmound]

So is the problem in the main jet block in the float bowls??
This is very irritating, a new bike, grrr....

 

[maleko89]

That's a guess, I would try running Seafoam and do the peashooter before dismantling the carbs though.

 

[diggerzmound]

That's a guess, I would try running Seafoam and do the peashooter before dismantling the carbs though.

I took the carbs out and apart, and found nothing. All of the pilot circuits were clean as a whistle. I removed all the pilot jets and found absolutely no obstruction. The pilot passages flowed carb cleaner good.

Now I am starting to wonder about a vacuum leak. I am looking towards the vboost. I get a slight rpm increase when i do the carb cleaner leak test, seems to be somewhere around the vboost.

The bike will rev about 4000 rpms with the choke on, and does the lean condition hesitation to fall off the rpms.

Any idea? :bang head:

I hate to take it to the dealer, especially since I have already dismantled it, I have argued with them on the phone, the WILL NOT warranty any carb work...

 

[maleko89]

Take your carbs off and then look carefully at the vboost boots. Cracks are sometimes hard to see because the clamps get in the way. Remove the mounting screws of the left-rear and right-front manifolds. The reason to remove these is because the other two manifolds have blind holes for one of the screws. Oil would seep out of here.....removing the other two manifolds prevents a mess.

Once removed, it's easy to get the clamps and boots out of the way for a better inspection. Look closely at the mounting tabs of the manifolds too. One of mine had a hairline crack....probably from someone using an impact driver to remove the "H" cover screw....I won't mention any names. (ME!) lol