Not enough revs

[westie6]

I have purchased a boat that has a 1600 crossflow sport motor driving the propeller via shaft streight of the back of engine so working at 1 to 1.Wanting to now what revs it should be running at.Doing about 45ks on the water.Cheers

[Omerta]

Like in a car, the number of revs you can safely peak at occasionally is more than what you would want to run at all day, and less revs = longer time between rebuilds. I'd have thought the long running revs shouldn't be more than 4-4.5k with occasional use (water skiing?) up to 5-5.5k. Just a guess though...

ETA: How many revs is 45k on the water? Is that the fastest it goes, ie it can't rev any more even if you wanted it to because the drag on the boat is too much, or are you holding back the throttle at this speed so as not to over-rev?

Edited by Omerta on Tuesday 22 December 18:49

[westie6]

At the 45ks its doing 4000 revs.If i give it more gas it starts to die.Have got new jets for carb which is a twin throat webber.Cheers

Edited by westie6 on Tuesday 22 December 23:39

[Omerta]

Well, again I'm no expert on boats or these engines but would have thought that's OK. Having said that... if it can't go any faster and assuming it's not rev-limited that means the load on the engine must be very high when it's flat out. It wouldn't be normal for an engine in a car to be under full load for more than a few seconds during acceleration, or occasionally hauling up a hill, so I'd expect you to need more frequent rebuilds than a car. Have you got a get-me-home outboard too, or a good set of oars?

[westie6]

Cheers for your input will keep on boating

[Richard Gee]

Get the carb jets checked. My old Xflow in my Westfield in the UK used to cough and splutter at higher revs until the jets were cleaned and the carbs(twin webber 45s) balanced properly.