First older Mercury project. Setback and prop questions...

[omcnut]

I just recently got my first older Mercury that I will be tinkering with since my 97 200 opti, which was a dissapointment to say the least. This is a 1979 Merc 200 hp on a 1979 Ranger 1750 DC Aztec. Motor runs fine but instead of shortening the shaft, I will be installing a hyd jack plate. How far a setback do you all think would be correct. I hav heard the farther the better, but from no one I would trust. Also, theres major prop slip and a terrible hole shot with the three blade prop. It is a 27p ss. I am looking to try a 4 blade but dont know whether to pitch up or down to stop the slip. Kind of stumped because Ive never had to swap props before. Thanks in advance.

[pointer]

Not sure what you mean by shortening the shaft - as in 15" mid?
Setback will vary from one hull to another, even of sisterships.
Is the 3 blade a ventilated prop? You'll want to pitch for max RPM all things equal, not necessarily for hole shot.

Unless you are trying to eek out every last MPH out of your rig, despite the cost, see what other hulls like yours are set up like. I'm not familiar with your hull so I can"t give insight on it. Some setback will allow you to run the gearcase higher, too much will make it undesirable.

Try and get the demons worked out of the current set up (post pics will help), and then seek improvements with setup changes. Those last few mph will likely be costly, but there is plenty of knowledge here on the board to assist you in spending wisely.

With the cavitation plate parallel to the hull, where is your propshaft in relation to the bottom of the hull?
What 27P prop is it?

Don't be disappointed, just think how you'll feel one you get it running strong!

cheers,

pointer

[omcnut]

LU is a twenty five inch. Prop is vented but not sure what else about the prop. Boat belonged to my grandfather, and he snt it on to me. The times I ran it the hole shot took a month, but then it was GAWWN! It has a custom jack on the back to make up for the long shaft. To my knowledge Mercury made two different 200hp models in 79. A expt-long shaft (25in) and an exlpt-extra long shaft (30in). I may be mistaken as I just got the boat yesterday and spent about 10 hours researching the new toy. And the hull itself is basically a vee in the front and a pad in the back. Hard to find the particular model of hull, as most are in the fencerow by now. Ive only seen 10 or so, and I own the cleanest two around. Ill try and get a few pics when I get the chance.

[omcnut]

Is there anyone who can tell me more about this particular motor on the board? I am more familiar with the OMC's but being a hand me down and as solid a motor as goes down the lake I probably will be holding onto it for a while. I have some jingle saved up, and want to get it in the shop asap. Its getting a new minn kota trolling motor, Bobs action hyd jack plate(once I decide a setback), Sea Star hyd steering(the stipulation that I would if I ended up with the rig: grandfathers can be bossy). After the completion of the three above, I will be taking a pick-up bed of props to trial and error and decide on two or three to keep. Thanks again

[pointer]

Post up some pics!

pointer

P.S. before you spend your cash, make sure it is running well. Seen way too many people do just that... .

[omcnut]

Sorry.. been busy at work trying to get ready for the 4th. May be able to get some pics tomorrow. Try and get them loaded up after I get back from work tomorrow night. Been a busy night shift week.

[outasite]

The 79 model is still the first generation engine.The main drawback is that the head bolts are part of the cylinder wall,and can distort the cyl when torked.On the good side they are known to be strong runners and when taken care of,bulletproof.Some parts are getting a little hard to get like the exhaust divider

[omcnut]

Grandpa said the merc had not 100 hours on it total, and estimated the last 25 to have been on the hose. And he has always drove it like a granpa would. Motor outta be on display somewhere. Im gonna get more info and pics of both motor and boat this weekend so as a few people who Ive been talking to can see what Im dealing with. So far Ive been asking loaded questions, but I appreciate everyones help so far...