Mariner 89, 136 V6

[dashaway]

She runs well on an 18' CC but top speed is about 35mph @4800 RPM, as RPM increases at to that range, she seems no to gain any speed. I bought it used and thought it should go faster on a light boat.<br /><br />Now, 4800 RPM is top RPM she can achieve.<br /><br />Is this a prop issue?

 

[Dhadley]

Re: Mariner 89, 136 V6

Its more likely not running on all 6 if 4800 is the top rpm umless the boat has a ton (literally)of water in it. Or its a really large pitch prop.<br /><br />Are you sure its running on all 6? All the linkages going to WOT?

 

[KCLOST]

Re: Mariner 89, 136 V6

Your recommended WOT rpm should be 5600-5800...<br /><br />CC's aren't exactly light however. What size prop do you have on it now? And it would be interesting to know what the level of your cavitation plate is relative to the bottom of the hull.<br />Assuming the engine is running on all cylinders this stuff could affect it..

 

[dashaway]

Re: Mariner 89, 136 V6

Thanks for the input, it's an 18' Parker CC, 1800 lb maybe. Also changed the water pump yesterday and did a compression check, four at 120# and two at 118#, that seems fine to me. How do I check the carbs?