Another prop size question.

[josh6347]

I have a 1983 Skeeter Starfire 175 w/ a 1985 Johnson 150TLCTE on it. I am running a 4 Blade 24 pitch prop on it right now. It's the prop that came on the boat from the previous owner. I think it bogs down on my hole shot and it takes a while to plane off. The boat runs at 4500 WOT with this prop on it. I've been told that the peak for this motor is around 5000 or a little more. That could be right or maybe not? I have also gone the Michigan prop selector route and they suggested 14 1/4 x 21. What is your take on this?

 

[walleyehed]

Re: Another prop size question.

Welcome aboard!

If we know the tach is right, it's serieously over-propped.
That engine likes a WOT RPM of 5800.
Understand that the HP of that engine is taken at 5000, and has a range of 4500-5500 that was specified in the era it was built. we also had better fuel in 1985 by a bunch...we don't have those qualities anymore and we've found it best to run the crossflows on up to 5800 to help prevent coking, carbon build-up, and we've found better performance over-all with a longer engine life too.
The MWC selector is going to put you into the system by what you enter...if the selector has a limited data base on your rig, it will not be as accurate, and Bassboats are harder to set-up because there are more factors involved, such as a pad-type hull, setback, jackplate, boat balance, and what you expect from your set-up....it all comes into play for proper set-up.
Your engine (CT) is an '83 by the way.
I would say, let's make sure the tach is right first. It can be verified with a shop tach at WOT, in gear-not Idle.
If your shop doesn't have this type of tach, I would consider a new BRP tach..If the tach you have now is as old as the boat-or engine for that matter, we can't count on it. If it IS close to being right, it's gonna cost alot more to rebuild the engine when it comes apart from running 4500RPM, than it will to replace the tach or verify the one you have, and then set up for proper specs.
If you are serious about setting it up right, this is the starting point for accurate data to know if we are headed in the right direction.
My next question would be have you done a compression test lately, and if so, what were the results, and if not, it needs to be done so we know we have a healthy platform.

 

[josh6347]

Re: Another prop size question.

I was planning on doing a compression test in the near future anyway. I can verify the tach as well. It's also good to know that my motor title claims it's an '85, but in reality it is an '83. Makes more sense. I really thank you for your input and will post my finding in the future to let you know what I found out. Thanks again.

 

[walleyehed]

Re: Another prop size question.

I'm sure we can help you out, we just need a few "known" variables to start with.

 

[josh6347]

Re: Another prop size question.

This could be a proverbial stupid question, but I'm going to put myself out there and ask it anyway. I have a brand new Autometer tach I bought for my little side project Chevrolet. Can I use in for my boat to replace place my old one? I don't see why it wouldn't work, unless there is something special about Marine tachs I am not aware of. Please be gentle in your response. I really am just trying to make due with what I have instead of purchasing a new one. i just want to make sure I can make it work first. NO such thing as a stupid question. Right?

 

[walleyehed]

Re: Another prop size question.

Not a stupid question at all..
I don't believe an auto tach will work on an outboard with a stator-type charging system. In the case of an outboard, it's best to stay with the components made for such. alot of the materials are different for corrosion protection anyway.

 

[josh6347]

Re: Another prop size question.

Well it was worth a try. Besides, the Autometer would look gaudy in my instrument cluster. Well it's back to the drawing board. You have just been awesome with your replies. I kind of felt that the different ignition set-up on an outboard would be the drawback and you confirmed it. I'm sure I'll have more posts in the future. Thanks Again.

 

[walleyehed]

Re: Another prop size question.

You are welcome!
Send me an email when you have time...
ktsander@st-tel.net

 

[Ron G]

Re: Another prop size question.

Hey josh kenny and the rest are awsome,i also have a 175 im tweaking on,
Hey Kenny im going to send you one also i have a question if thats alright.

 

[josh6347]

Re: Another prop size question.

I just got back from the lake where I was trying out the 3-blade prop. I dropped about 500 rpm's at WOT, but the prop lost contact with the water if I didn't have it trimmed just right. The boat launched better, but overall I didn't care for it. Plus, it was pulling to the right no matter how I had it trimmed. If I remember right, the 3-blade is around a 24" pitch. I am working on getting a new tach or verifying the one on the boat and compression testing the motor.
Ron G, what motor are you running on yours and what size prop? Or are you faced with the same problem as me? I'm on a budget and I can't afford to go out and buy props based on a hit or miss process. My pockets aren't that deep. That's why I am so thankful for Walleyehed.

 

[walleyehed]

Re: Another prop size question.

josh, can you give a manufacture and model of both props?
Sounds like a trim-tab issue with it pulling at any trim level.

 

[Ron G]

Re: Another prop size question.

Im running a 93 175 faststrike.ive been working with kenny and dale for over a tear off on to get my set-up just right.my props are 25p and making up alot of ground a little at time,i do understand about the moneydI ve got a thread on here to i'll be posting more on it tomarrow.do as kenny suggests.How high or low is your motor mounted?

 

[josh6347]

Re: Another prop size question.

josh, can you give a manufacture and model of both props?
Sounds like a trim-tab issue with it pulling at any trim level.

They are both aftermarket props with no markings on them whatsoever. It took me forever to find the pitch markings. One of them has multiple numbers on the hub and the guy at the prop shop said that those numbers can't always be trusted because hubs get switched fairly often.

 

[josh6347]

Re: Another prop size question.

Im running a 93 175 faststrike.ive been working with kenny and dale for over a tear off on to get my set-up just right.my props are 25p and making up alot of ground a little at time,i do understand about the moneydI ve got a thread on here to i'll be posting more on it tomarrow.do as kenny suggests.How high or low is your motor mounted?

I know the motor has been raised over time by previous owners b/c there are holes and markings on the transom indicating such. Should I measure from the bottom of the hull to the bottom of the skeg or how do you go about it? Never been asked how high or low my motor is mounted. I am learning real fast how easy it is for previous owners to get caught up in tweaking out a boat without inquiring as to whether or not it is beneficial for the boat's performance. Then it is left up to current concerned owners to right all the previous wrongs. You guys are awesome. Keep up the positive replies. Can you recommend a good, inexpensive depth guage. I think my transducer is taking a dump on me.

 

[josh6347]

Re: Another prop size question.

What's up guy's? I've been reading a lot about using Seafoam to decarb my motor. I've never used the stuff, but I understand that it is very beneficial. Any suggestions? Also, is it just as easy to get a new tach, instead of buying the equipment to verify my current one? I guess it's just up to me, right?

 

[walleyehed]

Re: Another prop size question.

Send me an email, Josh...
ktsander@st-tel.net
copy and paste this into your email browser..

 

[Ron G]

Re: Another prop size question.

With your motor straight measure from the cavation plate down to the bottom of your hull.I used the seafoam deep creep it is awsome and does help alot,im going to do mine again here soon and see what i get out after a year of running.

 

[josh6347]

Re: Another prop size question.

Kenny, I can't seem to reach you on your e-mail so I thought I would try here.
Compression test results:
Cyl. 1,2,3,4 were at 80
Cyl. 5,6 were at 75

What do you think?

 

[walleyehed]

Re: Another prop size question.

If the gauge is accurate, it's a bit on the low side....100+ would be better.
The bottom 2 being lower may indicate a possible carb issue at some time..partially plugged mains could do this...
I would try the sea-foam at 1 can for every 5-6gal of fuel.
Run that for 30gallons of fuel or close to.

 

[josh6347]

Re: Another prop size question.

If the gauge is accurate, it's a bit on the low side....100+ would be better.
The bottom 2 being lower may indicate a possible carb issue at some time..partially plugged mains could do this...
I would try the sea-foam at 1 can for every 5-6gal of fuel.
Run that for 30gallons of fuel or close to.

So, you say 1 can for every 5-6 gallons for 30 gallons. So, if the math is right that is close to 5 total cans over time, I assume. I just want to make sure b/c I've read where 1 can should do it. I'm not questioning your advice. I just want to make sure I understand your advice. One other question. I got the temp. guage hooked up, but it only reads 110 degrees. I know thats got to be low. What would be a normal operating temp. Thanks for all your advice MAN, you've been a life saver.