Mariner 2.0L 150 ELPT SN: 6443819, Looking for prop suggestions and some gen. info

[kbeeb374]

I just got an 84 ranger 370V with the motor in the title on the back. It currently has a prop with a "-25" stamped on the outside and 48-66008 stamped on the inside of it. i was told that he replaced the prop after hitting a stump or something and lost some speed. looking to replace this prop with a more appropriate set up. it is on a manual jack plate but i don't know how to tell what size..

I am also looking for general motor info like a schematic, parts list, etc.. as there are a few hoses that should be replaced as well as a new starter and other miscellaneous things.

Any help would be greatly appreciated!!

[JOE54]

order factory serv manual, drop pitch back some 23 or lower

[kbeeb374]

How low would you say is too low for the pitch? Is there a good guide available for selecting props for these older motors?
Also, this is a cheap boat and i don't know if i want to put the money into a SS prop are there good aluminum options?
Would 4-blades be better top speed wise or just hole shot acceleration?

Thanks!!

[kbeeb374]

Update: measured the Jack plate. It is 5" and set to about 2.625" down from the top.. assuming i measured right. also the diameter of the Hub part of the prop is about 4 3/4"

Measured the prop as best i could is seems to be 14x25p from this prop selector thing i should be getting something like a 14.375x21.. does that make sense?
https://turningpointpropellers.com/PROPWIZARD/

[OnTRAK]

What is your top speed (GPS) and RPMs at wide open throttle with your present setup as is?

[kbeeb374]

Well we were only able to measure through the navionics app and that had us going about 35mph. I don't have a tach so i can't tell what my RPM's are. is there an easy way to install a tach?

[JOE54]

need a w/psi gage and tach installed to monitor rpm and wpsi for set up and prop selection, boat should go faster than 35 faster, would find good stainless prop

[cajunrgfm]

You should figure out if it still has a 2:1 gearset or been replaced with 1.87 b4 you buy any props

[kbeeb374]

How would i figure out what gear set it has?

[JOE54]

should be 2:1 , theres links on here to determine ratio

[kbeeb374]

Ok so I installed an off brand tiny tach. I have it set to 2p1r and it reads about 800-900 at idle. I measure the prop to pad at about 3.875 or so. When I go to full throttle it takes forever to get out of the hole then I can only get it to about 35 mph and the tach is reading in the 7000's after trying to run it for a bit it doesn't want to idle at all. 14x25p aluminum prop. Are my tach settings right? What should I do?

[OnTRAK]

If your tach is right and, in fact, you're turning 7000 rpms, you are experiencing a lot of prop slip. You may have a spun prop hub, a junk prop, or a combination of both. Typically aluminum props just don't cut it. See if someone will let you borrow a 21" or 23" pitch Tempest and report your results.

[JOE54]

agree ^^^^ or laser 21 or lower

[kbeeb374]

Thanks guys. i'll see what i can do. don't know a lot of people with bass boats around