2005 RMK 800 bog at 7000 rpm

[Saltwater Cowboy]

So I am hoping someone here can shed some light on this issue. I just bought this sled to get back into the sport after 15 years out of it. I spent the past few weeks going over the machine to hopefully resolve any issues. When I had a chance to take it out for a little test I noticed a high rpm bog. When I get into the throttle it pulls great to about 6500 rpm, I then let off and got back into it and the bog came back at 7000 rpm and got out of it again and back on it for the bog to happen again at 7500 rpm. Thinking that once it cleans itself out after sitting all summer that it would go away I got on it a few more times but the bog never went away. Then when I stopped it would idle at 3400ish rpm. If I hit the choke the idle will come down to 1200ish rpm then when I flip the choke off it comes back to 2000 rpm. While checking over the sled I did check out the jetting, it has 490 mains and needles in the 3rd clip which is correct according to SLP's web site (it has twin SLP pipes). I contacted SLP to verify the info and there take on the situation is that if my fuel has ethanol in it then I am lean but this fuel should not have any ethanol. It pulls great in the midrange and runs great other than this issue. Not sure if this has any bearing but when it was sitting in the garage and I filled it with fuel (Shell premium with a good dose of Sea Foam to clean it out), I come out the next morning to find a bunch of fuel on the floor and the motor hydro locked. So I pulled the carbs out and cleaned out the floats and bowls. This has not happened since so I am assuming I fixed it. Any help with this would be appreciated. Thanks

 

[retiredpop]

High idle is caused by a lean condition in the carburetor pilot fuel circuit as you have proved by flipping the choke on to reduce rpm. It could be just a minor adjustment on the fuel screw or maybe different pilot jets are required. It could be some junk partially plugging the pilot jet too. I would pull them out to ensure they are totally clean especially after you had something stopping the inlet needle from closing off the fuel when it hydro-locked. You could also have an air leak around the carb boots. High speed bog could be clutching related or fuel related. Have you done a plug reading after a full throttle run for a 1/4 mile or more? Kill the engine after the high speed run using the kill switch and continue to hold the throttle open until it stops. If the plugs are grey or white that isn't good.

 

[Saltwater Cowboy]

I now have it almost figured out. I pulled the carbs apart to clean and check them. Turns out someone installed a float for a 600 in it. they are close but obviously different. It now pulls hard right up to 7500 rpm (had to let off cause the field was to small but was still pulling). But I had to make a couple of runs to clear it out first. And if you let it idle at all you have to let it clear itself again. I am now going to check the oil adjustment and work on fine tuning the fuel and air screws. Any other thoughts are apreciated.