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1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 1:12 pm
by Grady2011
Just did something really dumb and I knew better as this is not my first boat much less not my first Carver. I have been out of the boating scene for about 7-8 years and my wife was actually pushing me pretty good to go back and I wasn't really arguing.
So I bought a what appears to be a really nice '89 Carver 3807 Aft w/7.4 Mercs. The really dumb part is I bought it without having the survey done first. I don't know what I was thinking......
So I do have to have a survey done anyways for insurance purposes. While scheduling it on the phone with the surveyor he told me that during the sea trial we would be running the motors to 4300rpms and if they don't do that we will know we have an issue.
Well I know for a fact that neither port or starboard engine will not do 4000 + rpms because I took it out Sunday and ran them at wide open throttle. I do know that the Port engine WOT and the starboard was at maybe 3/4 throttle for the syn. to show motor running the same....
Now I am pretty darn nervous....
Re: 1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 1:14 pm
by Grady2011
.... I do know that it has been about 6-7 years since the last bottom job so I am hoping maybe the lake algae is what is causing this.... But not feeling to lucky either...
Re: 1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 2:36 pm
by hausherrs
4300 seems high. I Dont know what my my prop pitch is but im doing 28mph at about 4000-4200 downwind. Thats all shes got. I have a Carver 400 though with crusader 7.4s. Depending on which insurance company you have it will be easy or you will be dropped. When I bought my boat I started with Foremost. They took all the recomendations (EVERYTHING) in the survey and said I had to have proof they were all repaired within 2 months of purchase. That list included "Pinholes in bimini, stove burner not working, scratches in boot stripe, hull blisters, weeping rudder packing gland, hydraulic ram leaking". About $6000 in repairs. I let that insurance go. I got another more expensive insurance that just made me sign a paper with a couple things they requested to be repaired. I had them repaired.
Re: 1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 2:59 pm
by tomschauer
depending on the props reduction gear, weather conditions and weight of and on the boat, you may not get to 4300. It seems really odd to me that a surveyor would tell you need to get to 4300. Maybe you have the wrong surveyor?
Re: 1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 3:12 pm
by Samuel
The only dumb thing you did was buying a gas not a diesel. Call the insurance company and ask why do they need to run the engine wide open. That would been for you so you new what was wrong with the engine it is your boat now just run it up to 3600 rpm that's it, If the surveyor wants it wide open then the damages is on him.
Re: 1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 3:41 pm
by g36
Wow i'll l disagree with the previous comment about diesel. Not everyone wants or need a diesel engine and living on inland lakes is pretty much a waste. Also looks like wherebthe op lives too. Your not going to run it enough to see this big fuel savings compared to your increased maintance especially if you hire a mechanic. I can take care of my gas motors myself.there's diffently a place but a gas boat is not a mistake.

Re: 1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 5:02 pm
by bud37
Grady2011 wrote:Source of the post .... I do know that it has been about 6-7 years since the last bottom job so I am hoping maybe the lake algae is what is causing this.... But not feeling to lucky either...
I would call the surveyor back and ask how and why he came up with that number as above....tell him what you told us and that you do not feel comfortable running 28 year old engines max out for no reason...Fyi the bottom condition, fresh fuel etc will have a lot to do with it......good luck man , hope all goes well.
Re: 1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 5:06 pm
by Grady2011
hausherrs wrote:Source of the post 4300 seems high. I Dont know what my my prop pitch is but im doing 28mph at about 4000-4200 downwind. Thats all shes got. I have a Carver 400 though with crusader 7.4s. Depending on which insurance company you have it will be easy or you will be dropped. When I bought my boat I started with Foremost. They took all the recomendations (EVERYTHING) in the survey and said I had to have proof they were all repaired within 2 months of purchase. That list included "Pinholes in bimini, stove burner not working, scratches in boot stripe, hull blisters, weeping rudder packing gland, hydraulic ram leaking". About $6000 in repairs. I let that insurance go. I got another more expensive insurance that just made me sign a paper with a couple things they requested to be repaired. I had them repaired.
Wow... I sure hope the insurance company I am dealing with doesn't act like that.
Samuel wrote:Source of the post The only dumb thing you did was buying a gas not a diesel. Call the insurance company and ask why do they need to run the engine wide open. That would been for you so you new what was wrong with the engine it is your boat now just run it up to 3600 rpm that's it, If the surveyor wants it wide open then the damages is on him.
Lake Texoma is a big inland lake but there just isn't many diesel boats. I am a fan of diesels and all my personal trucks are diesels. I had a friend that had a diesel Sea Ray on the lake and it seemed to be more of a pain than anything. Heck he would put it in gear and it would throw water on the dock. Lol. Or coming through the marina idling and people were yelling out him about no wake. Lol.
Re: 1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 5:46 pm
by waybomb
For insurance, all you need is a value survey.
You bought the boat, so it's yours now.
If you want a mechanical inspection, find a darn good marine mechanic for that later.
And if this surveyor is your insurance company's surveyor, try a different outfit, like Charter Lakes.
I don't like running PV wide open very long, much less the Carver.
Surveyor sounds like a jerk.
Re: 1989 Merc 7.4's RPM's
Posted: August 8th, 2017, 10:22 pm
by Viper
Unless he's doing a mechanical survey and is experienced at it, a surveyor has no business rendering an opinion on runability strictly on whether it reaches a certain rpm. There's too many variables to make that type of determination. Heck, if the previous owner propped her a certain way to suit his needs, even new engines wouldn't reach rated WOT. Get a good mechanic to do an overall visual inspection, check ignition components, check the carbs, do a compression test, leak down, and hook up a vacuum gauge. Check fluids including trannys. Do an oil analysis if it makes you feel better but it's an '89 so you have to expect that she won't be perfect. Tell the surveyor that running at WOT doesn't matter to you, if it does, this may not be the right boat.