Well first time out really this year and it looks like one of the hydraulic lines to the drive tilt has ruptured.
Anyone familiar with a boat as old as mine, pre-alpha i believe, know a good place to purchase new lines? And any other tidbit of useful guidance in regards to their removal and installation?
I would replace all the lines at once if possible. What year is your MC? Does your model have lines that go into the sides of the transom assembly or 4 lines that go into a manifold at the bottom of the transom assembly?
That's not good for it being a quick fix, those are high pressure systems that can't have the lines partially replaced. Also you have to pull the motor and assembly out. I've seen some guys go the route of boring holes on either side of the transom assembly to run new lines and plugging the holes in the assembly to avoid all that work just to replace those lines.
Sorry about the bad news, I've read all about those old models from the 60's when I was studying up on my Alpha One upgrade from the same set up you have with the high pressure lines in the transom assembly.
Just be sure you don't get water into the system and cause damage to the pump.
Well i finally got around to installing that skeg guard i had in the plans for awhile.
What prompted the install was i wiped out another prop.
I originally had a 3 blade prop. Bought a 4 blade to replace it and had the 3 blade repaired as a spare.
Didnt take long and damaged the 4 so was running the 3 blade for the last long while.
Anyways since the 3 blade just got dinged i went to a local boat repair service where he convinced me that a 4 blade 13.25x17 would be what i need.
Well like every other professional marine mechanic i have met he was terribly wrong. Boat dropped at least 10-15kms in speed. Wont even begin to plane.
Does anyone here have a similar boat to mine that could advise me as to the best prop?
What matters is the RPMs at WOT. I know those old 120's have a fondness for using the 14+" dia 3 blade AL props and 17" pitch sounds like it would be right. Although a new 4 blade cupped prop with aggressive rake would sap a bunch of power. What would help is to know what the numbers are for the prop that worked best for your set up. If the numbers are right with that 3 blade prop ie: RPMs at WOT and speed then I wouldn't try to make it better as you found out it usually gets worse.
You do not want to use a prop on that motor that will lug it out and not let the RPMS get up, it could severely damage the motor.
The boat would hit 3500 rpm (original tach) with original 3 blade prop.
New 4 blade that i just installed boat would also reach 3500 max.
The only differance was with the 4 blade i got half the speed. Couldnt even begin to go fast enough to plane.
So i am assuming the 3500 is the best that motor is going to produce.
I think my best bet is going back to a 14-15" 3 blade with a pitch of 19-21.
All these "marine experts" keep pushing the 4 blades but from my experience and research a 3 blade is a far superior design.
This part is a bit of a rant but i am so fed up with these marine mechanics. So far not one single task from simple to complicated have any of them been able to complete.
Is it because the water up here is solid for 6 months of the year or are they all incompetent everywhere.
I am an auto mechanic and fully admit i know very little about boats however i have eventually been the one who has found solutions where the "proffessionals" have failed.
I have a very poor opinion of the people employed in this trade.
Sounds to me that you should just trust your own mechanical abilities. There is a bit to learn to about the outdrive, but the engine is just a 'Marinized' 4 cylinder Chevy Engine.
I would test your tach against the tach in a timing light to make sure they match. I did this with my 67 Islander as I was not sure how well the ancient tach still worked. Turns out it is close enough not to warrant a replacement. 3500 is still a little low for these engines (I have the 120 MC as well with a pre-alpha drive). If your tach is correct and the throttle butterfly in the carb is all the way open at WOT, then it's time to consider the prop. I'm running a 15D x 17P prop and get 4200 rpm WOT with a speed of about 32 MPH (51.5 KPH). This is a bigger boat and would expect the proper propeller for yours to be different.