Another Prop ?

[SKIDROW37]

My mechanic recommended that I run a 23 pitch 3 blade prop on my boat. The motor wants to bog down on take off. It has a 26 pitch 5 blade prop on it. Will a smaller pitch prop help it not to bog on take off? If so does anyone know where I could try a different prop b4 I buy one? If anyone can help I would appreciate it. Thx

 

[Oldman]

what kind of motor?mercury or Johnson?i have a 24 raker on my mercury.if u have a mercury u r welcome to try mind on yours.

 

[SKIDROW37]

IT's a 150 mercury not sure what year it is.

 

[Oldman]

my 24 might give u an idea of what u need.just let me know i live in soddy.

 

[wrechin2]

There are a so MANY variables. The 5 blade prop will tend to have a better hole shot even being a 26 pitch. If you have a 2L 150 and someone put a 1:87 lower on it off of a 2.4 150 or 2.5 150 that will cause of issue. The 2L was a small engine and did not have much torque. That is why they ran a 2:1 case. the 2:1 case is like 1st gear ina manual trans and 1:87 would be like 2nd gear. They will interchange and someone who doesn't know could have put one on. Just a thought. What kind of boat do you have?

 

[SKIDROW37]

wrechin2 - 8/1/2011 10:25 PM

There are a so MANY variables. The 5 blade prop will tend to have a better hole shot even being a 26 pitch. If you have a 2L 150 and someone put a 1:87 lower on it off of a 2.4 150 or 2.5 150 that will cause of issue. The 2L was a small engine and did not have much torque. That is why they ran a 2:1 case. the 2:1 case is like 1st gear ina manual trans and 1:87 would be like 2nd gear. They will interchange and someone who doesn't know could have put one on. Just a thought. What kind of boat do you have?

Norris Craft 1750. It didn't used to bog before they worked on the carbs. They said that the carbs were racing carbs idk if they are or not. It just seemed kinda funny that the prop is the problem after they worked on it.

 

[wrechin2]

Why did they have to work on the carbs? There are only a few sets of true racing carbs. I have 2 sets off offshore racing carbs that have tubes installed and slosh plates. They may have gotten the sync out when they installed them. I have seen many times that the trigger wiring cover will get hard and cause a delay in timing advance and this will cause a hesitation. Did you tell them you didn't have the issue until they worked on the carbs? You now have my curiousity up!

 

[SKIDROW37]

wrechin2 - 8/3/2011 12:05 AM

Why did they have to work on the carbs? There are only a few sets of true racing carbs. I have 2 sets off offshore racing carbs that have tubes installed and slosh plates. They may have gotten the sync out when they installed them. I have seen many times that the trigger wiring cover will get hard and cause a delay in timing advance and this will cause a hesitation. Did you tell them you didn't have the issue until they worked on the carbs? You now have my curiousity up!

I took it in because it was hard to start and would die when I would put it in gear if I didn't give it a little gas. At first they said it was the stator so they put one of them on it. Then they said it still idled a little rough so they started working on the carbs. They replaced the needles and needle sets and rejetted one of them and replaced the diaphrams and gasktets and whatever else they did totaling 1033 bucks. I got it back it seemed to idle better and idle in gear better but when I got ready to take of it was sluggish and took longer to plane out than usual. Then it got to where I would try to take off and it would bog like it was flooding or the choke was on but I could put it in N and rev it and it would take off better. I took it back and told them what it was doin and left it. When I went back to pick it up is when he told me that he couldn't find anything wrong with it and that the prop was too big and in hot weather would show up more than in cooler temps. This was my first boat and me not knowing if they were blowin smoke up my tale or not was the reason for asking the question. All I know is that it didn't bog before so why should the prop be a problem now? emoBadLanguage

 

[SKIDROW37]

James if you read this and think you may have an idea as to what went wrong please let me know. Your professional opinion is greatly appreciated. Thx.

 

[wrechin2]

First off, Sorry I don't get on here much anymore due to my work load. Please feel free to call me. My number is at my signature.

Most engines I build you have to give a little throttle when you put in gear or else it will die maily because the powerband has been moved up. But get the boat moving and it will idle forever. If a real big issue for the guy, I can install a piece off a late model 150/175 that advances the timing 3 degrees as soon as it goes into gear. This will usually stop the stalling. The problem is that the boat is standing still and then a large load gets put on the engine very similiar to letting out the clutch too fast on manual car/truck.

A hard to start is a different story. Most boats can be figured out on how to make start quicly. The engine in my picture required you to hold the key in for 14 seconds or it would not offer to start. Once I found out how long to hold it I could start it within 3 seconds each time after I primed it. Some only require 5 seconds. I don't know why they would have to rejet only one. That sounds awful strange to me.

But one thing that comes to mind is if they put a stator on it they may hae cause the trigger to not advance as quick. I have seen a lot of times that the trigger wiring will get hard and be slow to advance. If they cable tied the stator harness they may have hindered the movement. It is a very quick and easy test. They may also have gotten the sync out and not getting full throttle. I can sit here all night and give you possibilities.

One final question: Did you run the boat while the tempature was hot before you took it to them?

They charged $1033 for just the carb work??? If so all I can say is WOW! But not knowing what ALL was done it is hard to say anything about the price because it may be correct for the work performed.

 

[SKIDROW37]

Thx james