new prop

[Cam]

Yeah. What Reel said. That size prop is what I meant.

[tsubaki]

My best guess would be if you had a 6cyl OMC to think about a 17" or even a 19" if light loaded. If you got a few big assed buddies a 15" would be necessary.
But being you got a 4cyl the biggest I'd plan for would be a 17" if real light loaded. A 15" might be close to what you need if you got a usual load.

[THEFERMANATOR]

Are you SURE it's a 85 140 VRO? In 85 there were also a few crossflow engines turned out, and they don't quite have the top end punch and turn less RPM's. For that engine also there are 2 different gear cases that could be on it. A TRUE 85 140 will have the larger V-6 gear case with 2.25:1 gears in it, but most have been swapped out for the smaller 2:1 V4 gear case. you need to pull your current prop off and measure the diameter where it slides into the gear case first. If it is a 4" then it's a V4 gear case, if it's 4 1/2" then it's a V6 gear case. If it's a V6 gear case you also need to make sure it has 2.25:1 gears in it as the V4 doesn't have the bottem end grunt to pull the 1.86:1 V6 gears. If it's a V6 gear case with the 2.25:1 gears then a 17 pitch prop would probably be good. If it has the 1.86:1 gears then find another gear case for it as it will never run right. If it has a V4 gear case then look for a 15 pitch prop for it.

I know you were probably hoping for a simple answer, but with a 140(ESPESCIALLY 85 since it was the 1st year of that engine and a 1 year only if it is a true 85 140 looper) you just don't know what you could have until you check it out.

[reelapeelin]

Originally Posted by THEFERMANATOR

Are you SURE it's a 85 140 VRO? In 85 there were also a few crossflow engines turned out, and they don't quite have the top end punch and turn less RPM's. For that engine also there are 2 different gear cases that could be on it. A TRUE 85 140 will have the larger V-6 gear case with 2.25:1 gears in it, but most have been swapped out for the smaller 2:1 V4 gear case. you need to pull your current prop off and measure the diameter where it slides into the gear case first. If it is a 4" then it's a V4 gear case, if it's 4 1/2" then it's a V6 gear case. If it's a V6 gear case you also need to make sure it has 2.25:1 gears in it as the V4 doesn't have the bottem end grunt to pull the 1.86:1 V6 gears. If it's a V6 gear case with the 2.25:1 gears then a 17 pitch prop would probably be good. If it has the 1.86:1 gears then find another gear case for it as it will never run right. If it has a V4 gear case then look for a 15 pitch prop for it

I know you were probably hoping for a simple answer, but with a 140(ESPESCIALLY 85 since it was the 1st year of that engine and a 1 year only if it is a true 85 140 looper) you just don't know what you could have until you check it out.

.


V20.com...THE source of THE truth...and we all know the truth will set you FREE...it'll piss you off first, but it will set you free...

Good stuff Ferman...I had an '84 140, so I guess I dodged all that...it was a a great motor on a 17' Thunderbird...

[reelapeelin]

Found this in classifieds...after Ferm's post, ya never know what ya might need...



http://www.wellcraftv20.com/communit...ad.php?t=19263

[Steveib]

I took the prop off yesterday. I'm about to leave work and will check to see if its the 4" or 4 1/4" when I get home.

[aussie]

why do you want to change it , what is the wot on it and what are you not happy with the performance on the boat