Maximum engine weight for 1975 18' Holiday

[barbosam]

I picked up an 18' 1975 Holiday with a 1994 70hp Johnson for $1,000 this year. Boat and trailer are in very good condition and motor had only 32 hours on it. I have used the boat several times and it runs great! My only problem with it is that I wish it had a little more power for towing a tube.

In the short term I will be trying a few different props to see if I can improve the performance. But for the long term, I'm curious to know what the maximum engine weight is for this boat. I'd like to explore the possibilty of repowering with a later model higher power engine but I don't want to make the boat too stern heavy. I know maximum power is 140hp, but is their a listed max weight? I wonder if there is an owners manual for this boat?

 

[fshngho]

Re: Maximum engine weight for 1975 18' Holiday

Barbosam you can check out the Brochures thread. It may tell you. I believe most of the time the weight includes persons, equipment & motor. No weight specific to the motor just the HP

 

[grantcool]

Re: Maximum engine weight for 1975 18' Holiday

I have an 18' Starchief with a V-4 115HP Evenrude. I don't know what the motor weighs, but i want something smaller because this motor really pulls the stern down and the bow is pretty far up out of the water. And that's with the added weight of a cuddy cabin towards the bow! I can't imagine how low it would sink with a 140HP on it.

 

[Pugetsound]

Re: Maximum engine weight for 1975 18' Holiday

On the 21 ft Holiday My Holiday has as I said a 200 hp V6, Also on the transom is a 9.9 Merc 4 stroke and below the splash rail is 2 Batterys and 6 38# downrigger balls. Plus 2 scotty downriggers. Low stern has never been a problem It has a 21diamiter by 19 pitch prop, ( Aluninum) and will hit 50 0n good water. That is a lot of weight and no problen that I have found. I also hav a full width seat there which if fairly heavy. Power T/T on motor.

 

[Starman8]

Re: Maximum engine weight for 1975 18' Holiday

I know maximum power is 140hp, but is their a listed max weight? I wonder if there is an owners manual for this boat?

If your spec plate says 140 as the safe max HP, then find out what a 140 weighed on a 1975 model?

Appears to be about 300 pounds, just an example.

http://rides.webshots.com/photo/2620354250101354590nhdzTf

 

[ezmobee]

Re: Maximum engine weight for 1975 18' Holiday

The V4s should weigh pretty much the same regardless of whether you're talking about a 90 or a 140. Any 2 stroke 140 should be fine for your boat and not make it stern heavy at all. Now a 4 stroke.....no idea.

 

[Chinewalker]

Re: Maximum engine weight for 1975 18' Holiday

It's not a weight issue, it's a power issue. Static weight on a transom really doesn't do much to it. Torque on a transom is what stresses it. More howerpower equals more torque. I think you'll find that even upping to a 90hp V4 will be a big improvement in pulling power for tubing, etc., without the fuel consumption of a 140. I have a 90hp on my 18-foot American (fiberglass version of your Holiday) and it is a very nice set-up. Planes off easily, even with a full complement of passengers. With a light load it'll nudge 40mph.

 

[barbosam]

Re: Maximum engine weight for 1975 18' Holiday

Thanks, for the replies, definatley some good information. The boat also has a 25 gallon aluminum fuel tank underneath the motorwell (but above deck), plus two optima batteries (40lbs ea). Ezmobee, you make a good point, right now my 70hp (250lbs) is a three cylinder, from 90-140 they are all 4 cylinders and will all weigh almost exactly the same, probably 300-350lbs. I think If I repower I will relocate the batteries forward and this will offset the extra weight enough so that the boat still sits on its lines. Chinewalker, I think you're right, a 90-115hp would probably be more than enough while still maintaning good fuel economy, the fuel economy right now with the 70hp is amazing, but I'm willing to sacrifice some of that for a little more performance.

 

[ezmobee]

Re: Maximum engine weight for 1975 18' Holiday

The V4s are right around 300lbs. I believe.