I have a 97 merc xr6 150 that I just had a tuner and solid mounts installed on it and ran great for the first 2 trips out and has been running worse each trip out after. The symptoms are it will fire right up in the morning but have a low idle and after a good hard run and idle down it will idle at 1-12k rpms. As the day goes on it gets really hard to start, like its flooding, and when it does fire up it will start running really rough and miss, and the lowend power starts to struggle. I pulled the breather and ran it today in the driveway today and had noticed that the bottom carb and port that feeds #6 cylinder is pouring fuel out, its puddling up alot compared to the others. I rebuilt carbs a little over a year and half ago, Im thinking I need to do it again. Any input or suggestions would be greatly appreciated. Thanks

Pull tha bowls and check tha needle n seat fittings and gaskets in tha bottom of tha bowls. Have seen these work loose over time after a carb rebuild...........cleaning and new gaskets through out ever so often never hurt anything anyway.

Ditto, and did you rebuild the fuel pump? If not, get-r-done. You may also be experiencing a bad fuel bleeder hose connection. (The ones that cross over from the side of the block near the head and re-enter into the intake. If you are not using stabil or sea foam, your floats may actually be swelling up and locking down inside the bowl of the carb. We had that happen when the customer had 32% alcohol in his fuel.

I did the fuel pump when I did the carbs last. I use seafoam every other fill up on. It all started when started using 93 octane fuel and swapped back to 87 and started running a lil better in the morning but same results by the end of the trip. I disconnected the oil injection and I premix but I noticed it doesnt smoke as much as I would think it would.

Ive been looking for a carb kit on the internet and they're saying I should have a wmh carb but all of mine are wmv. How can be sure I'm getting the kit for my motor.

Do your carburators have two rectangular plates on top?

wmv's came in '96

Yeah mine has the 2 plates that sit on top with the black rubber gasket

WMV's.......

I pulled the bottom carb of and removed the bowl and everything is really clean and the float needle and seat seem to be operating smooth. Checked all bolts and nuts are tight, couldn't see any broken or loose hoses. I was thinking about running 1 gallon of gas to 1 can of seafoam through it and see if it would help anything out.

I had bad needles right out of the package once. You might just go ahead and change those neeedles out. Did you test the bottom carb by squirting some mixed gas straight in to the throat? Do that and see if it bogs or your rpms jump. Tech at the Merc training school told me once that the float settings on those carbs are critical but I have never had a problem setting them.

Could a bad fuel pump cause these issues?

what do your spark plugs look like? I had a similar problem on my xr2 and it was the little check valves that screw into the reed block that drain fuel back to the cylinders were stuck open. they have black spaghetti rubber lines going to them. I had 2 that were bad, and it really made my motor load up on fuel, and foul the plugs. I repplaced the bad ones, did a decarb with engine tuner in the spray can and put new plugs in and its doing much better. Im also switching from the blue jug wallart 2 cycle oil, to some pennzoil synthetic blend, and reducing the mix ratio to 60 to 1, since I primarily idle around or cruise at midrange .
you can test the little check valves by blowing in them they shouls seal in one direction, and free flow the other way. they have little plastic balls in them that act as check balls, that get out of round. So check them several times before you call them good, because if the liitle ball spins a liitle, it will seat, then then next time it might not.

Look close at the float setting and take a flashlight look at the reeds.

What am looking for when I look at the reeds? I looked at the reeds when I pulled the carb and didn't see anything irregular. I'm gonna swap my 150 carbs for 200 and see what it does. If anyone needs a set of wmv 150 carbs let me know, make a good deal on them.

Don't think that will work for ya. Just tha difference in tha jettin' will make tha thing "fat" and maybe a little "lazy". Might be better than whatcha got now though since they seem ta be givin' ya trouble (if it is tha carbs)...........

But if ya got fuel runnin' outta tha carb that pretty much is where tha problem is gonna be. Seems ta me tha wmv is about tha most "sensitive" carb Merc has ever come up with. Usually bad reeds will only show up at idle or just a little above idle and will be tha same whether its tha first start or tha 100th start of tha day. Won't show hardly any difference at speed....jmo