2 stroke question

As of right now.... no, I haven't had a chance to take the boat out but I have been talking to a lot of people and mechanics, and for eveyone I talk to I get different answers. I have found out that I am probably carrying too much unneeded weight in the form of rods, gear, weights and a few other items as well as I always go out with a full gas tanks for both motors. I always thought that over reving a motor is a bad thing and it is but what I didn't understand was under reving a motor is just as bad. Now I understand why you "punch it" to get up on a plane. If you take the revs up slowly when your trying to get on a plane you end up putting a lot of stress on the motor but if you punch it, then the motor will be working hardest to get on a plane while the revs are higher which actually is less stressful for your motor..... then once a plane is achieved the revs can be lowered to save fuel while running. I bet you now that when I go out again and I punch it (after it has had a chance to warm up) to bring it onto a plane I will achieve higher revs then before simply because I will be giving it more throttle then before. By the best of my knowledge a 1992 Yamaha 2 stroke motor should max its revs out between 4500 and 5500 RPMS(NOTHING MORE!!!), I'm thinking that as long as I can get it over 4500 rpms I am not going to mess with it because as I said under reving a motor is bad for it but so is over reving especially a motor that is 18 years old.

And remember....Keep your tip up!!!
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Steve, you need to be able to hit 5500 rpms at WOT.
anything less, you are not propped correctly.
Don't look for anything more complicated because i'm
99% sure that's all it is.
 
quote:Originally posted by r.s craven

Steve, you need to be able to hit 5500 rpms at WOT.
anything less, you are not propped correctly.
Don't look for anything more complicated because i'm
99% sure that's all it is.
X2
You need to get close to that 5500!
I wouldn't be worried about taking the boat anywhere? Just take the prop to someone who knows what they are talking about, tell them what's going on and get the right size props? Sounds like if you go down a size and/or pitch you should be fine?
 
I'll just have to wait till I can get out on the water to find out for sure and anything else short of that is only guessing.

And remember....Keep your tip up!!!
fish.gif
 
quote:Originally posted by Charlie

quote:Originally posted by r.s craven

Steve, you need to be able to hit 5500 rpms at WOT.
anything less, you are not propped correctly.
Don't look for anything more complicated because i'm
99% sure that's all it is.
X2
You need to get close to that 5500!
I wouldn't be worried about taking the boat anywhere? Just take the prop to someone who knows what they are talking about, tell them what's going on and get the right size props? Sounds like if you go down a size and/or pitch you should be fine?

The prop now is 13 1/2 x 16, don't think I can go much lower then 15

And remember....Keep your tip up!!!
fish.gif
 
Thanks Charlie and RS, I thought I wanted to go down in pitch not up but I will look into it and find out for sure.

And remember....Keep your tip up!!!
fish.gif
 
Down will give you more rpms. Up will make the engine work harder.
 
quote:Originally posted by r.s craven

Here's a great deal on a stainless Yamaha prop
13-3/4 x 21p
betcha it would solve your problem:)


http://www.usedvictoria.com/classified-ad/9976487

Betcha it'll make it worse..

If he's currently running 13-1/2 x 16....13-3/4 x 21 is gonna drop the rpm even lower...a lot lower (larger diameter and greater pitch...)

I've been trying to stay out of this, but he's getting all sorts of conflicting info and it's not helping!
 
Thats what I thought. Now I just have to wait till I can get back out on the water and open her up to see what the revs get up to. I'm thinking that its just me not reving it enough. Why would the motor be propped the way it is now.... there must be a reason. The old owner must have propped it that way for a reason.

And remember....Keep your tip up!!!
fish.gif
 
quote:Originally posted by Degree of Freedom

quote:Originally posted by r.s craven

Here's a great deal on a stainless Yamaha prop
13-3/4 x 21p
betcha it would solve your problem:)


http://www.usedvictoria.com/classified-ad/9976487

Betcha it'll make it worse..

If he's currently running 13-1/2 x 16....13-3/4 x 21 is gonna drop the rpm even lower...a lot lower (larger diameter and greater pitch...)

I've been trying to stay out of this, but he's getting all sorts of conflicting info and it's not helping!

Im not getting into it anymore either..

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Fill the dam tub!
 
[/quote]

Im not getting into it anymore either..

untitled.jpg

Fill the dam tub!
[/quote]

I just want to know how it really turns out. Would of loved to help if I was closer.

But I also gave up on this some time ago.

Sorry,
 
Thanks for your help but a lot of the advice I'm getting is nothing more then guesses and conflicting to the point of useless. Once I get the boat out on the water I will report back my findings.... simple as that!!! And I personally don't think its a good idea to listen to the advice of someone on line who I have never met especially when everyone says something different and like I said earlier, Thanks for your help but its not really helping.... Sorry!

And remember....Keep your tip up!!!
fish.gif
 
Free advice is not worth the price of a new motor. Pay a mechanic to check the problem out.:D

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If your in Victoria, call Marc at Runabout Marine. He comes right to your house and he also does sea trials.. He might have some props to try. 250-744-9720
 
Or better yet write down all the data regarding rpm (wot),what it does in the water etc and take the prop to Don at west isle marine in sydney he will let you take out props to try and spend the time and find out what works for your boat he is a world of knowledge and been doing props for a very long time.

Good luck with your venture

Wolf
 
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