2 stroke or 4 stroke for 14' inflatable

[whywhyzed]

Re: 2 stroke or 4 stroke for 14' inflatable

so do you have a 19 P prop or something for that 25??

I already have a 50mph+ boat (avatar), but it's made of plastic and is almost impossible to fall out of....haha

I've toyed with the idea of plunking the 30 on my 3.40 Avon Rover and see how it does...that's double the Avon's rating though. The 20 seems plenty on it...

I did stick my 9.8 merc on my 9' Sevylor once (rated for a 4HP) and after about 300 yards, removed it.... yep...I pussied out....

meow

 

[BC STS]

Re: 2 stroke or 4 stroke for 14' inflatable

kjdkjd when did you purchase your boat and was it from the seller located in Richmond on ebay? Are you guys serious about sitting on the floor instead of the seats? I was just going to support the seats with a cooler I have that fits snug and was gonna purchase another one for the other seat. Is a console only a good idea if you keep the boat inflated or are they easy to take on and off? I guess this requires a different type of motor too so I better decide now. I'm pretty choked my boat didn't come with the 6 loops in the front for a passenger to hang on to as there is nothing to hold on to up there. Will be giving the seller a call shortly to give em heck. Will take a look at the rivets too. I've been having trouble getting all 4 side rails to fit flush as one keeps popping out. Dealer said I could come buy and try a new set, have you had this problem?

 

[whywhyzed]

Re: 2 stroke or 4 stroke for 14' inflatable

ebay yes- a month ago - I think these are factory seconds or something. I also think the HIN numbers are maybe fake?. Mine starts CNY which is supposed to be Coronado Yachts' HIN prefix according to something I read on the net... kinda fishy. I got it registered ok - thought that might have caused a problem but it didn't.
The handles would be the least of my worries - you can glue on any kind of handles easily enough later.
see if it holds air reliably - If I didn't have to pay $200 shipping to return it, I would have returned the boat. Maybe I was spoiled by my Avon, these boats are "OK" but there are some issues. I feel comfortable addressing them myself but would rather have not had to. The seller did refund some $ for some of the problems I had.

The trick with the floor popping out is to first inspect and repair all rivets - if rivets are busted, the side bars might not be parallel. Then - with the boat only slightly inflated, take a nice smooth hockey stick handle or similar smooth wood stick and use that to very carefully center all aluminum floorboards to each other before full inflation. And make sure they're centered between the tubes. Then inflate it and they should stay locked in. The keel tube needs to be centered and pulled right back to the transom before floor goes in as well!

At the front corners of the front most aluminum plate, you'll see it's dangerously close to unprotected tube at the front corners- so protect it - I plan to glue in the black PVC from the patch kit. I just have towels in the corners now. There's a gap there and it's not an issue sitting still, but if you rammed the dock or something, I could see that tube hitting the aluminum edge....

A console or helm not a good idea if you plan to deflate and move the boat folded a lot. They mount permanent to the aluminum floor.

That was one thing that sold me on this boat was the alum floor. Odd looking aluminum though- like it's recycled from something else - all different widths of channel - strong though once you drill and rivet each piece of channel - that's the thing I didn't like - some of the pieces were not riveted to the side gussets. They are now on mine. The extra rivets also prevent the floor sections from going "trapezoid" - which is adding to the popping of side channel issues you're having I bet!

 

[whywhyzed]

Re: 2 stroke or 4 stroke for 14' inflatable

Well... in case anyone comes back to this one... I tried my old 20 Evinrude on the 4.3m. This motor is a 1975 so it's 20 crank, probably 18 at the prop. I was quite surprised. Acceleration was respectable, not as scary as the 30. Top speed was 21.5 mph (vs. 27.5mph w/30hp). Would certainly need the 30 to pull any watertoys or skiiers. I would say a 15HP 2 stroke would be bare minimum power on this boat. A 25HP 2 stroke would be quite fine for 2 or 3 people. The 30 is really only necessary for towing or for heavy loads (e.g. 4+ people). If someone really had their heart set on a 4 stroke - I would say get a 25HP or the lightest 30 you can find, but inflatables scream "2 stroke". 4 strokes are for dad's pontoon boat.
The ventilation issue I was having in the turns with my Yamaha was completely gone with the Evinrude so obviously the 'rude has the vent plate in the perfect spot for this boat. Need to raise the Yamaha 2" or 3".

 

[deejaycee_2000]

Re: 2 stroke or 4 stroke for 14' inflatable

8,5 ft inflatable with 30hp modified .....

 

[SandMan*]

Re: 2 stroke or 4 stroke for 14' inflatable

That's a huge looking 30... My 45 looks dwarfed by it!

But it could be because the boat is smaller than mine, I have a 12.5' F/G.

 

[the godfather]

Re: 2 stroke or 4 stroke for 14' inflatable

I would go for the 2 stroke over a 4 stroke any day of the week. The 2 stoke is a very simple engine needing less maintance than a 4 stroke. Plus they are lighter, much better throttle response and are faster. These are not myths but facts. A 4 stroke will use less gas per hour but a 2 stroke will go faster for the same HP hence you will go father giving you better MPG than a four stroke. Now if your going to idle all day the four stroke will use less gas. There was a great study done that I read somewhere on line on this very topic and what i Just said is what the study said. Either way there are plenty of 40-50 year old 2 strokes still running great. How many 40-50 year old car engines are still running with little to know maintance? That is want a 4 stroke outboard is, a little car motor.

 

[wbeaton]

Re: 2 stroke or 4 stroke for 14' inflatable

As much as I love my old 2 stroke outboards I have to say that your post is out to lunch, godfather.

Your speed vs GPH arguement is inaccurrant. Both use about the same fuel at WOT and both have about the same top speed. Also you can't compare car engines to outboards since car engines don't spend half of their lives running at WOT. Todays 4 strokes perform about the same as todays 2 strokes at least in the smaller hp's. No boat motor is "a little car engine". They work much harder than car engines.

 

[the godfather]

Re: 2 stroke or 4 stroke for 14' inflatable

As much as I love my old 2 stroke outboards I have to say that your post is out to lunch, godfather.

Your speed vs GPH arguement is inaccurrant. Both use about the same fuel at WOT and both have about the same top speed. Also you can't compare car engines to outboards since car engines don't spend half of their lives running at WOT. Todays 4 strokes perform about the same as todays 2 strokes at least in the smaller hp's. No boat motor is "a little car engine". They work much harder than car engines.

MMM last time I checked my mercruser 230 was a 305 cubic inch chevy engine. Other than the cam shaft its a car engine! It is in no way going to last as long as an outboard, the maintance is more, and its much heavier, and way more parts to make it run! No this is not an outboard but they all operate the same! The outboard manufactures have been making little 4 strokes now for about 15 years now. They have gotten lighter but are still not as light as a 2 stroke. Thats just a simple fact. When 4 strokes have been on the water for 30+ years you can argue your point for durability but now you really have nothing to base your facts on. At that point (30 years) I would suggest that you also include total cost of ownership. I'll bet the farm that the 2 stroke blows away the 4 stroke!

As to my GPH argument it IS accurate. I tried to find the actual report I referencing here but I can't find it and I'm not going to look all day for it. I was a very technical study giving actual fuel flow readings on 2 different 2 strokes and 2 different 4 strokes on the same boat. Both 2 strokes were faster WOT and did use the same GPH but because the 2 stroke was faster it gave bette MPH! When I run accross the study I will post it!

 

[wbeaton]

Re: 2 stroke or 4 stroke for 14' inflatable

MMM last time I checked my mercruser 230 was a 305 cubic inch chevy engine. Other than the cam shaft its a car engine! It is in no way going to last as long as an outboard, the maintance is more, and its much heavier, and way more parts to make it run! No this is not an outboard but they all operate the same! The outboard manufactures have been making little 4 strokes now for about 15 years now. They have gotten lighter but are still not as light as a 2 stroke. Thats just a simple fact. When 4 strokes have been on the water for 30+ years you can argue your point for durability but now you really have nothing to base your facts on. At that point (30 years) I would suggest that you also include total cost of ownership. I'll bet the farm that the 2 stroke blows away the 4 stroke!

As to my GPH argument it IS accurate. I tried to find the actual report I referencing here but I can't find it and I'm not going to look all day for it. I was a very technical study giving actual fuel flow readings on 2 different 2 strokes and 2 different 4 strokes on the same boat. Both 2 strokes were faster WOT and did use the same GPH but because the 2 stroke was faster it gave bette MPH! When I run accross the study I will post it!

I don't even know where to begin with that...

You need to do a little more research. Also, I believe the first gasoline powered outboard (known as a detachable rowboat motor) was an air cooled 4 stroke built in the 1890's. There have always been 4 stroke outboards. They are not new. Homelite built many back in the 1960's that are still running great today.

The Mercruser argument doesn't make sense. Apples and oranges. How come they don't just build a 2 stroke motor to take place of your 305 Chev?

Either way, I'm not here to fight or hijack this thread. There is lots of info on this topic in the archives.