15 3/4 prop for yama sws 250 TXRX ?

[Yama 250 fireman]

Will a 15 3/4 Dia. prop fit a 250 TXRX sws?

 

[Yama 250 fireman]

Re: 15 3/4 prop for yama sws 250 TXRX ?

Thought I would get a quick answer on here but, guess not..........

 

[rodbolt]

Re: 15 3/4 prop for yama sws 250 TXRX ?

wow your as bitchy as the rest of my customers and my wife.
yes the dia will fit but what pitch are you gonna try?
whats on it now?
may be best to post in the prop forum.
sorry I dont get off until about 5:30.

 

[Yama 250 fireman]

Re: 15 3/4 prop for yama sws 250 TXRX ?

Here is the story, I'll try not to be too bitchy, 1981 25 ft. mako yamaha 250 sws txrx, prop 15 1/4dia x 17p yamaha "M", ran 5500 WOT loaded. Well this prop was nicked, worn, blade tip bent, and so on. I found a nice used one the same pitch, dia. etc. better condition. This new prop dropped rpm down to 5000 with same conditions. I was thinking to go to a 15 3/4 dia. x 15 p.
15 3/4 just because I found one that size.

This "better condition" prop I got must grab the water better or something, but the older one runs great on the boat now even beat up. I needed a spare any how.

So what do you think? I have read alot of your post and they help me out sooooo much! Wanted to say thank you! In a bitchy way!

Also while I got ya, same motor has oil around o2 sensor and plugs, not that good brown color. Adjusted pump linkage to stop on the pin.

 

[Yama 250 fireman]

Re: 15 3/4 prop for yama sws 250 TXRX ?

Sorry about the prop forum thing just started doing this. Like I said I have just been reading the past post and getting what I needed. Great stuff!

 

[rodbolt]

Re: 15 3/4 prop for yama sws 250 TXRX ?

the oil around your O2 sensor most likly means the block was replaced since mid02 and someone used the wrong gaskets at a service,
the oil leaking past the plug gasket indicates improper plug torque.
sounds like your on the right track with a 15 pitch prop.

 

[Yama 250 fireman]

Re: 15 3/4 prop for yama sws 250 TXRX ?

The oil is on the inside, not leaking out. I am getting fouled plugs and wet o2 sensor. I did the bench test and also tested the o2 sensor while running, checks out OK. I found that the drain hose on the bottom of the intake silencer was clogged. I had oil on all of the intake openings. It looks like the hose goes from the bottom of the intake sliencer to either the bottom throttle body or the next one up. I cleaned it out and also all the oil. I will run it on friday. Any other thoughts on why plugs are fouled? Oil pump?

Like I said I did adjust the linkage. (released bottom two throttle linkage and adjusted arm so it was against stop pin)

Thanks for your advise!

 

[rodbolt]

Re: 15 3/4 prop for yama sws 250 TXRX ?

proper adjustment is .005-.020" with the shutter fully closed.
if you have oil inside the O2 sensor cover then you have a leak.
most likly due to either the wrong gaskets for the block being serviced or improper torque on the sensor holder.
sensor output voltage CANNOT be tested without the gearcase submerged and the engine warmed up for about 10 minutes.

 

[Yama 250 fireman]

Re: 15 3/4 prop for yama sws 250 TXRX ?

What do you think about the bench test that uses the propane torch?

I will check the o2 sensor Friday in the water nice and warmed up.

What could be causing the fouled plugs?

Motor runs great for one good day and then hard to start, misses, and loses rpm at WOT the next. After running though the motor seems to clean up and run fine, until I stop again. I know this is from the plugs. I will change them and it's like brand new again running like a bat outta hell.

I have replaced all three low pressure fuel pumps also.

 

[rodbolt]

Re: 15 3/4 prop for yama sws 250 TXRX ?

flame test = a teat on a boar hog.