4 stroke too heavy

[bonneauitall]

hi. i have a 77 starcraft holiday which leaks like a seive. i recently replaced the original 70hp johnson with a 90hp 4 stroke yamaha and i find that it is too heavy to the point of not being able to put a kicker motor on the boat. i will probable remove the floor to repair the many loose rivets and i was wondering if there is some way to give it greater floatation. anyone have any ideas?

 

[dingbat]

The F70 (70 hp) is 30% ( #109) lighter than the F90 (90 hp)

 

[Tagged]

Here in South Texas we fish a lot of shallow water. Many aluminum Jon boats have sponsons on the back which give extra flotation right where you need it, near the motor. You could weld a couple onto your boat. Depending on the size, you might get enough buoyancy to net about 50 lbs of flotation.

Downsides: (1) cost. (2) you probably still couldn't use a kicker, because the sponsons will be there. (3) the boat will handle differently (4) 50 lbs probably doesn't offset the weight you added with a 90 four-stroke.

Tag

 

[oldhaven]

Are you talking about water coming over the transom cutout sometimes due to the added weight? It may not be enough, but if your boat has waterlogged flotation and soaked or doubled decks and transom from all that leaking it might lighten things up a lot to replace them. You could also think about moving battery and fuel forward or midships if that is back there too. What length is your Holiday? You don't need much of a kicker and could use a very light one if the boat is 16' or less. Another thought is that a reliable new main 4S motor may not need a kicker if it satisfies your trolling needs.

 

[jbcurt00]

I wouldnt weld anything onto an aluminum Starcraft hull thats built w rivets.

If this is an 18ft Holiday, its likely rated for a 125-140hp, depending on year. I'd bet either 1 of those motors is much closer to the 90hp Yamaha heavy weight then the 70hp 109lb savings Dingbat posted.

What year 4cycle? I thought most of the new 4cycle OBs could throttle down really low for trolling, and troll all day? No need for a kicker?

 

[laurentide]

Flotation doesn't affect buoyancy until you're sinking...

If that's what you were asking. I.e. more foam won't help that situation. I agree with the other guys that you probably have to forego the kicker, or get a wider boat. If it's an 18'er(?) they're only 82" beam, less at the waterline.

 

[Pusher]

The local dealership down here sells the main motors with electric trolling motors mounted onto the main. Not sure if you fish salt water or if they make a salt water electric yet.

Tagged sounds pretty dead on. Get that wet foam out if you haven't already. Water's 6 lbs/gallon I think. You could put play pit balls in until you get the leaky rivets bucked.

Are Sponsons the same as transom mounted pods? Wouldn't a full width one get more than 100 lbs of flotation?

Another pro to a pod is the fish cooler can strap on the back out of the way.
Not sure how bringing a big fish in would be working around that.

 

[GA_Boater]

hi. i have a 77 starcraft holiday which leaks like a seive. i recently replaced the original 70hp johnson with a 90hp 4 stroke yamaha and i find that it is too heavy to the point of not being able to put a kicker motor on the boat. i will probable remove the floor to repair the many loose rivets and i was wondering if there is some way to give it greater floatation. anyone have any ideas?

There is your problem. Motor weight has nothing to do with it when the boat is already heavy.

Time to fix the leaks, then worry about motor weight.

Welcome to iboats. Please check your Private Messages.

 

[g0nef1sshn]

Unless i missed it? Not one of you has asked for pics yet???


We need pics to make this official.

 

[Pusher]

Unless i missed it? Not one of you has asked for pics yet???

We need pics to make this official.

Good one!

 

[Pusher]

I had to google a sponson. Not what I expected. Here's what I was thinking

This should be easier on your hull and if you built it wider it would hold a cooler . A lot of the guys in the sound in Washington use these to convert to OB's.

 

[Watermann]

Welcome aboard :wave: I'm guessing you may need a change of names. :lol:

DO NOT continue to operate your 1977 Holiday with loose rivets and compromised decking, side panels and transom as it can and will cause structural damage and be unsafe.

What length is the boat? It should have white Styrofoam type flotation foam which doesn't absorb near as much water as pour in foam used later in the 80s. There are tons of restoration theads with volumes of information on repairing and restoring these old boats here at iboats at the top of this section.

 

[GA_Boater]

Adding sponsons is a cover up of a problem, if it would work. Adding 100# of motor weight means if you are normal size and move from the helm to the rear of the boat, your 100+ pounds back there will sink the boat. Holidays handle larger motors just fine - If they aren't in danger of sinking from leaks!

Fix the leaks and go from there.

Please read posts before commenting. :doh:

 

[pckeen]

I have a 90 4 stroke Yamaha on my 18' Holiday - no problems.....but the boat doesn't leak.

 

[bonneauitall]

the boat is a 18 footer that i use for salmon and halibut fishing on the open ocean. i will post some pics when i go down to the coast to fix the boat, i live and work inland. the kicker is mainly as a backup and is a 6hp 4 stroke yamaha. it would be nice to use the kicker for trolling as well to save fuel. the difference between the 70 2 stroke and 90 4 stroke is 150lbs. I'll check the foam under the floor when i remove it. the issue is water coming over the stern when i am jigging halibut in the open sea, along with the leaks it is a bit much for my bilge pumps. I'll see how much the leak repair costs me before i consider the pod. love that boat, it's a fish killer

 

[pckeen]

OK. So when I'm on the lake, if I'm moving backwards in waves, water will splash over the transom and drain out the drain holes, but the holes themselves are above water. If this is happening to you, I would say that is normal. I did a similar repower to yours and it didn't significantly alter how the boat sat in the water.

However, if you are continually taking on water in normal usage, to the point that the bilge pump can't keep up, you are either going out in water way too rough for that hull, or you have a significant leak(s).

 

[Watermann]

I agree with the above and add nothing good can come to the health of an aluminum boat being full of saltwater all the time especially since you can't ever rinse it out of the inner hull.