Need to PROP. HELP ME .. PLZ

[longstand]

I tested this boat for the first time over a year of repairing the Engine..

I have tested the boat on the water and SLOW. i mean SLOW..

well question is..

What is the best PROP to get for this kind of boat.. i have twin engine

Engine Spec:
OMC V6 3.8L

here is the Picture of my Current Prop. i has 3 Blade.. i have read about Pitch and size it all matter. and needs match with the Engine ..

 

[Bondo]

Re: Need to PROP. HELP ME .. PLZ

Ayuh,.... Please, Read this 1st,...
Then repost with the answers to the questions posed...

At this point, the best props are the 1s on it....

 

[steelespike]

Re: Need to PROP. HELP ME .. PLZ

Without more specific info its difficult to tell what you need.
More than likely as Bond-o said the present props are probably best.
If you give us the prop size,present max rpm and speed.Describe the performance.
My hunch is there is more going on than prop selection.Actual hp and max rated rpm would help as well.

 

[longstand]

Re: Need to PROP. HELP ME .. PLZ

ESSENTIAL DATA REQUIRED
When posting a question about propellers, you cannot get a reasonable answer unless you provide the following information in your post: Items 1-4 are essential for meaningful response to most questions.
1) Performance issue you are trying to correct.
2) Current prop manufacturer, model, aluminum or stainless and as a minimum.
3) Current prop diameter and pitch (required).
4) Wide open throttle RPM and speed with an average load (very helpful)
5) Engine/drive make, model, year, and HP
6) Boat make model, year, length and weight

The Engine RPM was about 3000 and the Move Slow for such a High RPM. it say its moving about 15MPH on the Gauge.

My Current prop is Original. dont know if its Aluminum or stailess.
Current prop diameter and pitch. dont know how to tell. i could get the diameter. i will get it and post it this afternoon but the pitch dont know how.

Engine is OMC with Sterndrive (not Cobra) its a 1983 Boat

Boat size is 24'
Weight is 4,200

 

[steelespike]

Re: Need to PROP. HELP ME .. PLZ

You should find the prop size on the barrel or under the prop nut.
Prop diameter will help a little but won't mean much.A prop shop can measure pitch for you.As I understand it its a twin are you running both engines?
Both have good compression and well tuned? throttles opening all the way?
Bottom clean?Could boat be holding water in foam under the floor boards?
Is the timing advancing as it should?

 

[MRS]

Re: Need to PROP. HELP ME .. PLZ

longstand, that first photo you have should have the information on it. Look at the numbers on the hub and see if has something like a (14.25X17) and that will be the dia. and pitch of your prop. hope this helps you.....

 

[longstand]

Re: Need to PROP. HELP ME .. PLZ

You should find the prop size on the barrel or under the prop nut.
Prop diameter will help a little but won't mean much.A prop shop can measure pitch for you.As I understand it its a twin are you running both engines?
Both have good compression and well tuned? throttles opening all the way?
Bottom clean?Could boat be holding water in foam under the floor boards?
Is the timing advancing as it should?

Yes. i run both of my Engine. is it possible to run just one engine and still go forward. last time i try i was going side way.

The bottom of the boat is clean...

JEZZZ i have never thought that will cuz problem.. it was raining here in san diego. 2 or 3 days none stop. the cabin was flooded. no electrical was damage just wet. i try everything. and everything seems dry.

but there is that little hole under the steps toward the cabin where it has a CAP which allow me to open. and it has water. it has Hoses around that little area. which i assume its normal to have water in that area. because there is hoses which lead to outside the boat. but no pump. i will put a small pump later in that future..

but as for that little water. is that a big problem of why my boat seems so slow. maybe it add a little bit of wait. but i just dont see why it will effect the speed..

as for Engine Timing. I time the Engine as the Book said.. 10*Degree BTDC. . its not advance.. engine idle around 700 RPM. but most of the time it dont usually stay at that RPM it jumps around 850 to 700 RPM from time to time.

throttles open all the way.. I dont know what you mean by this. but i assume the Carburetor throttles open all the way just fine. and if you mean if i open the throttles all the way open and if the engine still run without a problem then yes. it does work properly..

Carburetor is not well tuned. it runs and stay alive. and keeps its lower RPM. and when i push the PEDAL to the FLOOR and CLOSE it. ENGINE STAY Alive. ..

NO backfire.. sound preaty clean..

i will video the engine running when i have time. so you guys could see. i will post it on youtube and post link here..

but for the PROP

 

[cribber]

Re: Need to PROP. HELP ME .. PLZ

Okay just a shot in the dark and not sure if this an issue... but which way do both outdrives rotate the props? Your setup looks like both props are clockwise rotation. From what I've seen on dual setups (mostly OBs) one is clockwise the other is CCW. Good luck!!!

 

[steelespike]

Re: Need to PROP. HELP ME .. PLZ

As far as water weight If the boat was repeatedly exposed over the years to water standing in the bilge Foam under the floor could absorb water enough to make performance sluggish.Clould be slow to plane because the weight would be heavier toward the stern.To check throttle;with the boat warm idling in forward shut it off.With the flash supressers removed from carbs advance the throttle to full throttle(motor off)The throttle plates down in the carbs should be open. As far as timing goes The distributors have a mechanism that advances the timing as the motor rpm increases.Sometimes they get stuck and don't advance.While the props could turn out to not be right they should plane the boat.While not easy with one outdrive raised the boat should proceed on the other.Might even plane if running really well.
To the untrained ear it's possible you may not notice if one cylinder was dead.

 

[longstand]

Re: Need to PROP. HELP ME .. PLZ

Sorry for a very very very late reply.. been busy..

Ok Like a mention before.boat seems to move really slow..

My Remove the PROP and i seen the Size.. its a15x17

 

[steelespike]

Re: Need to PROP. HELP ME .. PLZ

Have you checked the things I have mentioned?
Motor response in neutral doesn't mean much.
How is the compression.
It appears you have twin 188 hp motors 15 X 17 props should be close.
Speed should be 40+.In my opinion the boat should plane on one motor 25-30 mph. with one outdrive raised.Yes steering would be difficult.
With the motors off if you open the throttle all the way do the butterflies in the carb open comepletely? Have you checked that the timing advances all the way?
Setting the timing only sets the startiung point.The timing should advance as speed increases.If it doesn't you will lack power.
Do you trim in all the way for hole shot?Are both motors operating on all cylinders?
Are the chokes opening all the way? If it won't plane with 376 hp something is very wrong.

 

[longstand]

Re: Need to PROP. HELP ME .. PLZ

Have you checked that the timing advances all the way?

I have been timing my car for a while. and i did time my the boat.

*i belive its 10* BTDC and thats what i did. when the engine is accelerating the timing do advance. but how do i know which timing mark it should be pointing at on certain RPM?

*I open the throttle all the way and the butterflies in the carb open comepletely!!

No, i have not check the the compression check yet. i will get back to you on that..

Do you trim in all the way for hole shot? I usually put both engine on the MIDDLE. it has a Gauge Saying IN/OUT and there is Middle. i usually put it on the middle. i have not master this Function yet. its my first time. but i have been reading about what its function and know what IN or OUT do and purpose.

*Are both motors operating on all cylinders? How exactly Do i figure this out.. Remove all spark plug and check all the Compression.. will that tell me if the cylinders are working

I will work on it when the RAIN STOP. i live in san diego its been training for days. almost none stop.. even my boat is flooded

 

[erikpn]

Re: Need to PROP. HELP ME .. PLZ

Have you checked that the timing advances all the way?

I have been timing my car for a while. and i did time my the boat.

*i belive its 10* BTDC and thats what i did. when the engine is accelerating the timing do advance. but how do i know which timing mark it should be pointing at on certain RPM?

*I open the throttle all the way and the butterflies in the carb open comepletely!!

No, i have not check the the compression check yet. i will get back to you on that..

Do you trim in all the way for hole shot? I usually put both engine on the MIDDLE. it has a Gauge Saying IN/OUT and there is Middle. i usually put it on the middle. i have not master this Function yet. its my first time. but i have been reading about what its function and know what IN or OUT do and purpose.

*Are both motors operating on all cylinders? How exactly Do i figure this out.. Remove all spark plug and check all the Compression.. will that tell me if the cylinders are working

I will work on it when the RAIN STOP. i live in san diego its been training for days. almost none stop.. even my boat is flooded

You gotta to cover it... boats are not waterproof on the inside, especially older ones with wooden stringers/deck/transom. If the boat is regularly flooding and sitting full of water it's going to be destroyed. Have you ever put the bow up and fully removed the drain plug to see if the boat is full of water?

 

[longstand]

Re: Need to PROP. HELP ME .. PLZ

You gotta to cover it... boats are not waterproof on the inside, especially older ones with wooden stringers/deck/transom. If the boat is regularly flooding and sitting full of water it's going to be destroyed. Have you ever put the bow up and fully removed the drain plug to see if the boat is full of water?

Actually. my boat dont have any Wood. beside some TRIM and trail. and the Steps. its TEAK wood. beside that nothing in the boat is wood. no wood on the engine bay. no wood in the cabin. beside minor. like drawer. the bed.. the only thing that got flooded is where people walk on. and thats about it. and minor water stain..

but yes your rigth. boat is not water proof. i put the regular boat cover that boat has and 1 tarf on top of it.. i kid you not. still get wait inside. i need to buy a plastic cover or something.. iam getting tired of this crap. LOL everytime we have heavy rain it get like this. but if it rain for about half a day. nothing happen it stay dry. but 4 or 5 dayds of heavy rain. geszzz

 

[Bondo]

Re: Need to PROP. HELP ME .. PLZ

but there is that little hole under the steps toward the cabin where it has a CAP which allow me to open. and it has water. it has Hoses around that little area. which i assume its normal to have water in that area. because there is hoses which lead to outside the boat. but no pump. i will put a small pump later in that future..

but as for that little water. is that a big problem of why my boat seems so slow. maybe it add a little bit of wait. but i just dont see why it will effect the speed..

Ayuh,... A Dry bilge will make a World of difference....
Boats without bilgepumps,... Sink....

 

[steelespike]

Re: Need to PROP. HELP ME .. PLZ

You should trim in(prop closer to the boat)for hole shot.In my opinion a healthy boat would plane in the "middle" setting but it would take longer.
You would have to find out the maximum advance but you could try to observe if they both advance the same amount.If I was going to check that each plug wire was firing I would partially loosen each wire at the distributor cap.Then with the engine idling pull one wire at a time with insulated pliers and obsrerve any change in the idle.If you pull all the plugs you may note one or more that are wet.If 2 wires were crossed then while they both were firing you would have 2 dead cylinders.
I think I would start with a compression check; pull all the plugs and you can observe their condition.Let us know the compression.

 

[longstand]

Re: Need to PROP. HELP ME .. PLZ

i do have a pump inside the engine compartment i have one at the front and one big big one on the read between the two engine .

water drip into the corner into the cabin and the from cabin get filed with water.. i live up a hill and there is no wayt for me to park the boat with the front Facing the house. lol. i could park in up the hell but scare someone will play stupind and remove the BLOCK and there goes the boat (down the hill)

000
0000

i been reading this over and over
"If 2 wires were crossed then while they both were firing you would have 2 dead cylinders."

i dont understand this part. its my english may not be so good.

 

[steelespike]

Re: Need to PROP. HELP ME .. PLZ

If you put one wire on the wrong plug then it follows that another wire could be on the wrong plug parhaps without any obvious results except poor performance.
If you observe the engines at idle they should be smooth, no shaking.If one or more cylinders are dead or missfiring the motor may shake a little.
If you raise one outdrive out of the water and lower the other all the way (prop close to the boat.You should be able to test each motor enough to see if it lacks power.Yes it will steer strangely but you should be able to run it enough to comepare how each is performing.You will be running only the motor that is in the water.You also need to determine if one or both motors have a performance problem.