mercriuser wot speed?????

[alexprihodiko]

i have a 86 mercruiser 140 with a alpha one outdrive on a searay seville, asumming that the boat still has all the original componets, ex. prop, outdrive, engine. wat is the max speed it will obtain at WOT. my original tach went out so im using a tach i got from a buddy, the tach saying i at 2100 doing 33-35mph. the tach came out of a six banger, so i think the engine size screws need to be ajusted for a 4 banger. im just trying to figure out what the factory settings are for speed at WOT, without any tweaking. the hour meter says 470, i pretty sure its original.

 

[Bondo]

Re: mercriuser wot speed?????

i have a 86 mercruiser 140 with a alpha one outdrive on a searay seville, asumming that the boat still has all the original componets, ex. prop, outdrive, engine. wat is the max speed it will obtain at WOT. my original tach went out so im using a tach i got from a buddy, the tach saying i at 2100 doing 33-35mph. the tach came out of a six banger, so i think the engine size screws need to be ajusted for a 4 banger. im just trying to figure out what the factory settings are for speed at WOT, without any tweaking. the hour meter says 470, i pretty sure its original.

Ayuh,... It oughta be runnin' 4200/ 4600rpms at Wot...

I'd say yer tach is off, for sure...

 

[cr2k]

Re: mercriuser wot speed?????

Speed is gonna depend on many things: weight of boat, added water weight from soaked flotation foam, number of ppl onboard, legnth and type of hull (tri or V) prop, amount and grade of fuel, condition of hull, trim, on and on...

 

[TomB985]

Re: mercriuser wot speed?????

Bond-O is correct, as usual. An engine that doesn't run correctly or is propped incorrectly may not see 4,200+ RPMs at WOT, and low RPMs are a typical sign of incorrect setup. But I don't see it being possible to run 33-35 MPH at 2,100 RPMs, so it sounds like your tach is off. Once you get that sorted out you should see 4,200-4,600 RPMs if everything is running right.

My 2011 Larson/Merc 4.3L will do 4,600 RPMs at WOT.