1994 150 Merc Carbs

[Panaseaya]

I am considering rebuilding the carbs on my 94 150hp merc black max and was wondering if I should be attempting to do so. I have rebuilt the carbs on an old 40hp yamaha and did fine. I will buy a manual to help me along, but will I need any special equipment to tune the carbs for each cylinder or is it fairly easy? Also, any helpful hints would be greatly appreciated.

 

[LubeDude]

Re: 1994 150 Merc Carbs

If you did the 40 HP, you can do the 150, there are just more to do. Getting the manual is a good Idea. Spring for the needles and seats and you will have a great running engine when done providing there are no other problems.<br /><br />Why are you doing them in the first place?

 

[andy6374]

Re: 1994 150 Merc Carbs

Does anyone know if there was a service bullentin for this engine on the jet sizes? I know mine (88' V6 blk max) were initially to lean when the engines first hit the market. <br /><br />Panaseaya, it might be something to look into while you are at a rebuild. Rejetting is cheap and simple.

 

[Panaseaya]

Re: 1994 150 Merc Carbs

I just purchased the boat and motor a month ago and the owner let it sit for a year or so without using it. I wasn't able to take it out on a sea trial and figured what the heck, it's a deal too good to pass up, even if I have to buy a new motor. <br /><br />I took it out for the first time last week and the rpms would not go above 4,000 except when I back off of the throttle a little then "goose it". I replaced the fuel filter and fuel/water separator then tried again hoping I may have fixed the problem. No change, in fact, this time it starts to run hot. So, now I have to replace the water pump as well. Just trying to save a little money so I thought I would rebuild the carbs myself and let the mechanic fix the water pump (because of the headaches).<br /><br />I was told that, for this motor, replacing the water pump every year or so and keeping the carbs clean should be all that I have to do.<br /><br />As far as tuning the carbs, do I need any special meters, or can it all be done by listening?<br /><br />I should tell you too that I'll be replacing the fuel pump and the fuel lines under the cowling.<br /><br />Sorry for rambling, just thought you should hear the whole story.<br /><br />I greatly appreciate the help and info.

 

[andy6374]

Re: 1994 150 Merc Carbs

If you get a OEM manual, you can do all this stuff yourself. No special tools or meters.<br /><br />First: When running in salt water it is wise to replace the impeller and water pump gaskets every season, as well as the t-stats (or at least testing them). These two things are first and foremost to keep that beast healthy.<br /><br />Secondly: I would clean the carbs and reassemble with new gaskets every other season, unless you run something like seafoam through your tank a few times a season. Fuel pump. If you don't run a premix, keep up on the oil injection system. And every other season or so rebuild the pressure relief system or at least inspect. <br /><br /><br />Basically keep on top of the fuel (this means the oil injection as well) and cooling systems and she should never self-destruct.<br /><br />The cooling system can be easily monitored if you install a water pressure gauge.<br /><br />I've even heard of replacing the head gasket every 3 seasons as well.<br /><br />-andy