HELP!!! Stock '04 carbs

[Sledhead212]

I have a stock 2004, it does have the v-boost switch to kick in at 4 grand. The bike runs rather rich, can smell it when you stop. Milage is near 30 to the gallon. I don't want to change the headers, pipes or air filter for more power. I am interested in doing some carb work to clean up the low end burble when the bike is cold. I tried doing a search on here (still new) and found all kinds of infor for this can or that pipe and header combo.

I live in MN apx 850 feet of elevation. I'm 240# or so. Wife won't ride on the thing (seat to hard for her bum). Anyone have any set-ups that will work for my bike? Any of the sponsors have a kit that they sell that will work for my bike?? Thanks for your help.

Tom

 

[4gasem]

So it's a stock bike and you want more MPG? Try going down one main jet size. They're rich from the factory. 147.5 main should do it.

Leave it at that! DO NOT put a "jet kit" in it.

Do a thorough cleaning of the carbs while you have them out as well.

Chris

 

[tugla]

and float setting check for sure. +1 one the carb kit, can get mileage and power at the same time

 

[Sledhead212]

Are the jets a standard Mikuni jet or are they something a bit different? I have a tone of jets from the snowmobiles (grass drag mech). The bike smells rather rich (heavy exhaust) when I pull up to a light and wait. Seems rather sluggish till it hits the 5-6k on the tach. then it pulls better. Not looking for more milage per-say, just want to eliminate the burble and get the heavy exhaust smell gone. I have noticed some blow back in the air box (slight backfire when cold). Figured it was from the pipes not being hot enough to pull the exhaust out of the motor.

Thanks for the baseline help. I'll pull the jets and clean the carbs.

I love this site!!!

 

[dannymax]

and float setting check for sure. +1 one the carb kit, can get mileage and power at the same time

This could be a lot of your problem, the max seems to like a leaner setting than richer....I use 17mm.

 

[06VMAXIMUS]

First I would determine if someone else (P0) has messed with the carbs. Have the brass plugs been drilled out, exposing the mixture screws? If so, I would check to see where they are set at by counting the turns in until seated. Stock should be approx. 2 turns if I remember correctly. Stock main jets are Mikuni 152.5's. I think they all smell rich when sitting at the stoplights,...mine always has. A stock Max should be getting about 40mpg as long as you are riding it reasonably.

 

[Heretic]

I would adjust the A/F first. If you can smell gas at idle, then this will work to correct that and may help correct your stumble. If this doesn't correct, then you can mess with changing jets, checking float levels etc. Start with the simple and easy, As many have said here, stay away from the Stage 1 jet kit.

 

[Sledhead212]

First I would determine if someone else (P0) has messed with the carbs. Have the brass plugs been drilled out, exposing the mixture screws? If so, I would check to see where they are set at by counting the turns in until seated. Stock should be approx. 2 turns if I remember correctly. Stock main jets are Mikuni 152.5's. I think they all smell rich when sitting at the stoplights,...mine always has. A stock Max should be getting about 40mpg as long as you are riding it reasonably.

The brass plugs are still there. Prev Owner was not mechanical at all, so the bike was totally stock. I added the v-boost toggle switch. As far as the AF screws, what way is leaner, in or out? I know how to tune the sleds <2 stroke>, bikes look to be the same, just a few more carbs.

 

[06VMAXIMUS]

In=leaner. I wonder if its the tboost switch making it run funky. How was your mileage/performance before adding it?

 

[06VMAXIMUS]

If your gonna tear into the carbs, make sure to check the wet level first on each one. Then pop them off and go through them, cleaning all the jets and passages. Set the float level, and make the jet changes if desired. Put in a new fuel filter and re-sync them when finished. If you go to the carb section of this forum, you can find some great "how to's" on removal, cleaning and adjusting them. Let us know how it turns out.

 

[Sledhead212]

In=leaner. I wonder if its the tboost switch making it run funky. How was your mileage/performance before adding it?

Ran the same, V-boost hits at 4k instead of 6k now. More fun around town. I can turn it off so boost is not used at all. Milage is the same as it was before. If I go on the hiway, I set the boost to 6k <passing gear>.

Thanks for the help. It'll be apart in a couple of days.

 

[06VMAXIMUS]

Gottcha. Gas mileage can go to crap on these bikes if you ride them "spirited". Maybe the old reliable "shotgun or peashooter" method will clear things up and save you having to break into the carbs. Its not bad to tear into them, and if nothing else you will at least know they are clean and adjusted properly.

 

[Sledhead212]

Took the carbs apart and cleaned with a can of "Motor Tuner" (cleans the carbs really well). Found nothing to dirty or gummed up. What I did find was that all the fuel/air screws were set different. Made them all the same 2 turns out from seated. Bike liked that the best. Can't tell if the A/F ratio has changed but, it stopped popping out of the pipes. I left the mains stock for now. No need to make changes and try and fight it later on.