View Full Version : 2005 Indmar 350 Carb hesitation on acceleration

06-21-2012, 10:46 AM

I have a 2005 Moomba Mobius LSV with the 350 Indmar engine. The engine idles and starts fine. When accelerating from start it stumbles and sometimes dies. There is no smoke or smell of gas. If the engine doesn't die, it catches up and runs fine. Unless I let off the throttle then I have to go through the same stumbling.

I checked the levels and they have enough fuel. I manually did the throttle myself on the carb and opened the secondaries and it seems to have the same issue either way.

Any ideas would help!


06-21-2012, 11:06 AM
Check the accelerator pump, when throttliong up there should be a extra stream of fuel injected into the carb. Have somene with safety shield on watching down the carb and then with the transmission lock out engaged throttle up some. The watcher should see and hear the extra fuel being injected into the carb. If not then the accellerator pump needs fixed

06-21-2012, 11:09 AM
...somene with safety shield on watching down the carb ....

Safety shields are for suckers. Just stick your eyeballs down there and see what is going on. Safety shields do more harm than good.

06-21-2012, 11:49 AM
Safety shields are for suckers. Just stick your eyeballs down there and see what is going on. Safety shields do more harm than good.

Yeah I know... been around lawers to dang often... now I'm paranoid LOL

06-21-2012, 12:45 PM
Thanks for the tips. This only happens when it is under load. I've just had the moomba dealer look at it again and told them to look at that part.

Finding parts for the carb is a pain in the but. Holley is a really common carb but auto part stores freak out when you tell it's on a boat.

Parts Guy: Holley carb (looks on computer and books). What is it on?
Me: On a GM engine. Just looking for a 2.5 power valve
Parts Guy: Nice. I found a few things here. What kind of car is it in?
Me: It's a boat.
Parts guy's head explodes.

Speed shops are the only success i had with them.

06-21-2012, 01:21 PM
AH so the dealer has it now, cool. Let us know what they find out.

06-21-2012, 03:46 PM
mine did the same thing..i have a 04 outback w/ 350 FI and it would idle then when u give her gas to go it would bog and almost die..it did die once on me when i was bringing it to the boat ramp/dock..if it wasnt for a buddy and someone else the boat would have creeped up the boat launch a tad bit and killed my bottom..but after i replaced the fuel filter, fuel pump and tried my best on cleaning the injectors she has ran mint so far..only once 2 weekends ago did she bog for a min but once i put her to full throttle it cleaned her out and havent had any problems since ( fingers crossed, knock on wood ) haha

06-21-2012, 08:01 PM
Get the model number off of the carb and search online stores for parts (Summitracing, Jegs, or Skidim). The chain auto parts store guys seem to only know what the computer will tell them. Since there seem to be less and less gearheads working at these places today, you need to find work-arounds to help them out.