ok, this is the deal, i have a 2011 mud buddy 5500 black death with 68 hrs. on a 16-44 intimagator hull with twin mikunis, yesterday i was out on the river to just ride around and drink a few beers after work, i put the boat in the water cranked up first time fine like it should, put it in gear and started to drive. got about 50 yds, and gave it full throttle, everything fine, went about another 50 yds. and it just died, no sputtering no coughing or skipping, just dies as if i turned the key off. i sat there in disbelief for a few mins and drank a beer, went to crank it up and it took forever (like 2 mins) to crank back up, put it in gear gave it full throttle went a little bit and did the same thing, kept doing this, but i noticed it would only die when i was running wide open and let of the gas to maybe about 3/4 throttle. sat for a while cranked it up and drove it wide open at like 4200 rpm for about 15-20 mins, drove fine. got to the rice fields let off a little bit and died, waited got it cranked back up, drove a little bit, stoppped (on purpose this time) and drank another beer. cranked back up and drove about half throttle, but noticed it didnt seem as torquey as normal, did a u turn, same throttle position, about half, and it died again. sat and said wtf about 100 times and drank more beer. every time it died it "coughed" right at the end, kinda like it just ran out of gas or somethin. i had me and two friends and a good size cooler of ice and beer. and a 6 gallon gas can full of new 93 gas, which is what i always run. it idled perfect at 1000-1050 rpm when in nuetral, im kinda thinkin its the carbs, but im not sure, im gonna check today to see if theyre in sync. also looked up on the net today and some people said they has the same problem and found out it was a bad kill switch, which kinda makes since because thats how it seemed the motor died, like u turned the key off or pulled to kill switch tether. i just wanted to get some other input from other mud motor owners. i know im all over the place with this post just tryin to give all the datails and tell exactly what happened, the motor has 68 hrs and has never given me a problem til now. also everytime it dies and i had to crank it up it took A lOT of times to get it to crank back up, like A LOT, but anyways thanks in advance for any help.

When trying to restart the motor after it died, did you notice if the tach was registering rpm's?

ck your vent on your gas tank.

Drink more beer....

Ck all your fuel connections to make sure there is no air leak anywhere-especially if you use quick connects..

Drink more beer....

Check/change your air and fuel filters.

Drink more beer.....

Then start looking at carb issues.....

Never heard of the kill switch problem you describe and it sounds more fuel than fire to me....

If you just filled up, you could have got bad gas...

Drink more beer....

It is usually the drinking more beer that fixes it.

When was the last time you used the engine prior to this?

Sounds EXACTLY like what mine did when i first got it. Check your vent, dont' have to much extra(wasted) or air leaks in ur gas line.. or if your lazy like myself i added a electric fuel pump. Been running fine ever since

Sounds like a fuel issue imo, Did you try squeezing the primer ball while it was dieing to see if it would pick back up? Being that you loose it on the top end leads me to believe its starving for fuel whether it being an air leak or some sort of blockage , That would also explain the trouble with restarting it too . I had a similiar problem a while back the culprit! My father in law was standing on the fuel line! check the simple stuff first!

Thanks for all the fast responses guys, I took the boat out the day before and it ran fine, also I have a electronic fuel pump, and I saw no leaks anywhere around the quick connects, and I thought about bad gas but it idled perfect and when I had it wide open there was no sputtering or backfire or anything. I dunno.... But anyways thanks again andkeep ideas coming please.

Yea the vent was the first thing checked after the first time, it was where it always is, and the pump is mounted on the transom right by my seat and it was def pumping when it was messing up and its wired to the key, also I talked to a friend of mine who races late model stock cars his whole life so he is somewhat mechanically inclined at the least, and he thinks it sounds like the carbs, like the main pilot is f* up, and it kinda makes since, but then kinda not, maybe more buds will fix it

Clean your carb bro!

Josh, have u checked to see if electric pump is pumping consistently. Bypass w/ brass fitting, pump the bulb & give her a try. I had a permanent fuel line connector on tank & kept losing gas at wot. The fuel line had deteriorated at the tank connection. Outside the line looked good but ínside diameter was 1/2 what it should be. Cut off about 2" , reconnected & no problem since. When @ wot the Mikuni really asking for a lot &the loose connection was pulling air. If motor has been running good i would fool w/ carbs last!

yea, im getting rpms when i turn the motor over, thanks to all for advice and i guess im gonna redo the the whole fuel supply, tank, hose, new connectors, and filter and all that stuff, still baffled by the whole "not as torquey" thing at about half throttle, then haulin ass wot like is should, i had three people and a healthy cooler and other junk and was leavin my buddy with just him in his boat, granted i have a bigger motor, same boat. he has a 4000 with single carb and some engine work, but when it would act right i would leave him, esp on top end, and his boat isnt a slouch by any means. also i meant to put this in earlier, i noticed when it was messin up, after i drove it for like 20 or so mins, i started lookin at carbs to see if there was somethin obvious, the carbs were really cold, like ice cubes, and it was like 100+ degrees outside the other day, dont know if this is normal or what, i dont normally hold the carbs while im drivin as you would imagine, not sure if this is some sort of indication or a lean/rich problem or what, just thought i would mention, thanks again

alot of good info here for you. i also would get rid of the quick disconnects.just one more thing to go wrong. u might also consider running 5/16 line instead of 1/4 fuel line. and also with the high price of 93 octane fuel the high price of this fuel is in less demand today. street rodders today are building alot lower comp. engines so that they can run 87 or 91 fuel. and they are the large consumers of this fuel not us lawn mower guys. i once got a bad tank of 93 in my old coupe and went and asked the owner how much of this fuel he sold a week after i told him what i found i wasn't asking for my money back or any thing and he told me that he sold alot in a week. thats when i took a meter reading off his pump most fuel pumps have a little fuel meter on them that the station owner can get agallon reading off. and came back in two weeks and he had sold i think less than 50 gallons. thats when i started buying my fuel than and today at a speed shop. your cold carbs have alot to do with dew points. and the volume of draw on the fuel system. but iced up in hundred degree temps thats amazing. if they are truely icing up like u said that is a problem in its self. but those problems usaully show up worse at a idle than at wot. but they will show up also at wot and provide the same problems you are stating.

Ok thanks for the answer, does anyone have more info on the whole cold carbon issue, they weren't literally icing, but they were really really cold I took some gas and sprayed it around all the quick connects and the tank and there is no air leaks or holes to be found, which leave me to believe its the carbs or possibly somethin else. But it idles perfect, I mean it doesn't skip a beat, I let it idle for close to an hourwaiting for my othere friend ro et out there that day, I was scared I was gonna drain the batteryfrom trying to crank it so many times, but he whole time it never sputtered or anything, just as perfect as she could be.

josh. you need to work with us a little. here is a a few things u can do. pull the drain plugs on the bottom of carbs. use clear glass jars one for each carb. let it set for a while u should be able to find water dirt or cloudy looking fuel. if those problems are there than u need clean tank and maybe clean carbs. why u have the plugs out pull out the jets and look at them. most people don't use those connects they are just one more problem down the road. also verify your spark yes the tach will verify spark at the wire its hooked to but not the other. verify at your pump that u do have indeed have battery voltage and maybe not a loss of voltage. think back and did this problem start shortly after refueling. i would start with the putting new gas lines on a clear see thru fuel filter and than give it a go. iceing of the carbs happens most in the 40 degree or colder temps it is a mixture of cold temps and high dew points. it is the large amount of fuel mixing with large amounts of air.causeing the ice condition. the iceing cuts down on the air mixture.

Well my assumption was correct, tired of messing with if, took it to dealer and the carbs had to be tuned. Starting to wonder if all the bad things I heard about twin carbs is true. Well see though I love the bottom end end torque this setup delivers....