2 stroke question

[Sea Ranger]

Thanks Bananas, I'm going to pull the prop off on Saturday and take a look at it then. Maybe once I have the prop off then I'll let you know if I need a hand, thanks for the offer I really appreciate that.... I wish I could take someone out for a run to listen to how it sounds now before I take it off....Steve.

And remember....Keep your tip up!!!

 

[bananas]

you don't have to take your prop off it should say rite on it.

 

[Last Chance]

I typically like to prop my boat so I can hit the upper end of the MAX rpm range with about 3/4 load. That way, I'm not lugging it, I think it's better to have the engine rev a little higher then lug.

Last Chance Fishing Adventures

www.lastchancefishingadventures.com
www.swiftsurebank.com

 

[Sea Ranger]

Right after work I'm heading to Kelseys for free wing night but I will check and see if I can read what prop I have. I have been surfing and have found out a bit about props and stuff and I do believe the problem is all in the prop.....lol. (I think I hear an echo)

And remember....Keep your tip up!!!

 

[Island Fish Lifter]

Good call Steve. Definately the first thing to do without jumping to conclusions is find out whats on there now. If you came back on and said you have a 13 1/4 x 17, Id say you definately have a prob somewhere else, But I think youll find the props way too big. By the way I am a marine mechanic...

Fill the dam tub!

 

[profisher]

Another way to think it through..a 17" prop moves 17 inches of water for each revolution..a 15" pitched prop moves 15 inches per rev. It is easier for the engine to push 15 inches than 17 inches thus it spools up quicker and there is less load on everything. The only down side is your top speed decreases slightly as you reach top rpms sooner. (run out of revs) Your other question...2 strokes prefer higher rpms i combination with less load...4 strokes (automotive design) prefer lower rpms and will take more load.

 

[Sea Ranger]

Thanks profisher, I took a look at the prop and the only markings on it that I could find is: 16-K
I have no idea what those numbers are so I'm still going to pull the prop off. I was looking at props and noticed 3, 4, and 5, bladed props. Does it matter if you put a 3 or 4 bladed prop on an outboard and whats the difference. Sorry for all these questions but the last thing I want to do is blow up my motor..... still have to finish paying for the boat before I can replace the motor.

And remember....Keep your tip up!!!

 

[nedarb2]

different blades give optimum performance in different speeds. The only practical choices are 3 vs. 4 blade (5 is just going overboard).
$ blade gives best perfomarnace at cruise, 3 is better for speed, in a nutt shell.

 

[Sea Ranger]

Thanks nedarb2, I'd be better off with keeping it to a 3 blade prop. Good to know!

And remember....Keep your tip up!!!

 

[CIVANO]

Not necessarily. A 4 blade gets you on plane more quickly, allows you to stay on plane at a lower speed which might save fuel. The downside is a small loss of top end speed. I changed last year to a 4 blade and will never go back to a 3. If you indeed need a different prop, you can go to a prop shop and they will most likely let you try both.

 

[Sea Ranger]

Well, maybe a 4 blade prop is the way to go. I'll start looking around and see which boats have a 3 blade and which boats have a 4 blade prop and go from there.

And remember....Keep your tip up!!!

 

[Sea Ranger]

Ok, I removed the prop and the prop size that is on the boat is
13 1/2 x 16-k. I'll phone S&G and see what they say but I don't think the mechanics are working on a Saturday. Fish Lifter..... What ya think? or anybody? Steve.

And remember....Keep your tip up!!!

 

[profisher]

I would try and find a 15 inch on loan and try it for a trip and see if you get some improvement. If not you can look elsewhere for a problem.

 

[nedarb2]

It doesnt sound like your prop is the problem, your missing like 1000rpm from your top end...
I would get somebody to look at it and investigate - if your engine like you said sounds like its running balls out at full throttle your tach might just be out of whack. If not, something sounds like its restricting your engine. Spark plugs or dirty fuel filters maybe? Have u pulled out a plug and seen if there dirty or clean?
i wouldnt rule out a wrong prop yet until your engine has been looked at, but it sounds like less of a probability now.

 

[Tofinoguy]

quote:Originally posted by CIVANO

Not necessarily. A 4 blade gets you on plane more quickly, allows you to stay on plane at a lower speed which might save fuel. The downside is a small loss of top end speed. I changed last year to a 4 blade and will never go back to a 3. If you indeed need a different prop, you can go to a prop shop and they will most likely let you try both.

4 blades help when you run in rough water like we as you are at lower speed. My boat can stay on plane @ 16 knots.

 

[Island Fish Lifter]

Steve, that should be plenty to get you in the ballpark. Maybe Your next move should be to verify that your tach is working properly. The best way is to check it with a photo tach. but its a bit of a "technical" process. It may be best to hire a mechanic to go for a ride with you to take the reading. It may be as simple as an improper setting on the back end of your tach. Let us know. K? Dave.

Fill the dam tub!

 

[Charlie]

quote:Originally posted by C.S.

Stop guessing and take it to a dealer,get them to put it on there Dino machine.If you can get your full rpm on the machine then you know its a prop/pitch problem...Maybe a hours work,90 bucks well spent!

X2

So, I guess you finally get my 2 cents, to go along with the others!

Your remote tachometer mounted on the dash, more than likely does “not” give an accurate reading. While the reading is close enough for most of us, the only way to get an accurate reading is to hook the tachometer directly to the engine. You may not be able to “just listen” to determine a problem? Yea, you might have a bad gage or sensor, but i doubt it?

It sounds like you indeed are missing about 1000 RPMs and that needs fixed! I have had to resize props more than once! And, it has always been due to, additional gear added and never from anything else mentioned, but those are all valid concerns. If I am not mistaken, everything everyone has stated here is correct! It is a good idea to check and keep an eye on everything mentioned for the obvious reasons. However, normally the reason you need to re-prop is (1) you have damaged your old one (could be from excess cavitation) or (2) added “weight" to your boat. Most likely, over time you have just added additional weight (eg all that new gear and fancy fishing stuff).

You all ready have the prop off. At this point, take the existing prop to someone who knows what they are talking about, show it to them, and tell them what is going on! Take "their" advice!

You can have everything else checked but based on what I am reading, I believe you just need a different prop! As stated, most shops will let you buy, try, return, and exchange if necessary. A smaller prop or pitch will get you “out-of-hole” and up “on plane” better and increase your WOT RPMs, but will also reduce your “top-end” speed, but most importantly a “properly” matched prop will reduce the excess wear on your engine! It is very important, as stated by others, if you are not running the proper prop, to get the recommended RPMs @ WOT - you will be doing harm to your engine, period! End of story!

Stop guessing!

 

[CIVANO]

I agree with all above - my only additional thought is that I learned the hard way that the dealer and mechanic where I take my motor for tune up knew nothing about matching the boat/motor and prop. even though they presented themselves as experts. There are experts in that field and they specialize in props. My dealer said forget 4 blade props they are for bass boats. He was very wrong. I had complained for years about sluggish performance and he said I was getting what I should get. I discovered that in fact I had been over proped with too much pitch.

 

[Charlie]

quote:Originally posted by CIVANO

I agree with all above - my only additional thought is that I learned the hard way that the dealer and mechanic where I take my motor for tune up knew nothing about matching the boat/motor and prop. even though they presented themselves as experts. There are experts in that field and they specialize in props. My dealer said forget 4 blade props they are for bass boats. He was very wrong. I had complained for years about sluggish performance and he said I was getting what I should get. I discovered that in fact I had been over proped with too much pitch.

Sheesh... X2, again!
I only take my boat and listen to the one's I "know", know what they are talking about!

 

[Sea Ranger]

You guys are great!!!! All good advice and I will talk to the mechanics to see where I go from here. I even got Charlie involved....lol. I really don't want to take the boat into town so I'll see who is out in Colwood and take it there. I do have a lot of gear in the boat and at times there can be gear for 4 guys including weights and hali rods, anchors, downriggers, spare cannon balls not to mention big guys too. I can see that being an issue, again, all good ideas thank-you. Steve.

And remember....Keep your tip up!!!