New boater, Questions over 165hp 250 gm six, and merc outdrive

[Sharps-Nut]

I am a newby both here and to owning a boat. That said here are the questions. Where and who's repair manual would you recommend for a very mechanically inclined boat owning newby. I can do about anything to older cars so I tried to buy a boat in the same generation but would like help on buying a manual. The boat I bought is a 1977 caravelle 18.6 foot with 250 gm inline six cylinder engine. The hour meter only showed 286 hours and is currently working and seemed to match the rest of the gauges in appearnace and age but I realize thats no garantee. That seemed like terribly low hours. The engine area is very clean and neat and seemed absent of the usual wire spliceing and jury rigging I saw on other older boats. How much trouble do these engines give in marine use, and how many hour on average are they able to produce. How tight should I operate it if I want it to live a long life. I took the boat out once in oct just after buying it. It ran 40 mph according to speedo @ 4000 rpm. I didn't buy it for a speed boat but 4000 sounds like a lot of revs for a inline 6. Will this thing pull a couple adults on a tube ok or is it underpowedred for this. We bought it to tube and ski behind for kids both small and large. No one in our family has ever been boat people. It has always seemed like a good family activity that no one has had the time to pursue. The old boat is in really nice shape no rotten floors and very neat interior. The previous owner had just spent 1100 on the lower unit and had the receipts to prove it. Is there any thing I should be looking at before boating season? I winterized it and have packed the wheel bearings, rewired the trailer but know nothing about what the motor slash lower unit might need. I did also change the oil in the unit to protect from freezing. Help me know what things might be weak, need attention or to avoid to prolong this old boats life. Octane needs, oil change intervals, timing needs, everything you folks think a newby might need to know. Also I bought a trim meter at the urging of a friend and have no idea how to wire it in so input there would be appreciated. I know its a long list but any advice would be appreciated. Thanks in advance to any and all who can help. S-N

 

[Trent]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

First off its a great marine engine. You should have the "R" drive with that year model. Make sure to grease the gimble bearing several times a year. Before you add that trim gage you need to look at the wiring outside the boat on the starboard side (inside the gimble housing). My bet the wires to the trim sender are bad. They rot. They are a pain to replace. And you will need a trim sending unit also as they dont come installed. I believe they only come as a kit now for the trim limit and trim senders now?? If the waterpump in the drive has not been changed in the last three years it should be done. Change oil every 50 hours. I personall perferr Mercrusier manuals. Here are a couple of good sites I think will help you in the future. <br /><br /> Manual <br /><br /> Mercrusier <br /><br />Common problems with the Mercusier is shifting/stalling when the boat gets a little older. This is usually corrected by installing a new lower shift cable. You will also need to remove the outdrive every year to grease the u-joints on the driveshaft. You can buy the gaskets thru your local NAPA autoparts store. If you need the part numbers let me know.

 

[hoot]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

welcome to boating SN. i have had an inline 6 since 1978 and it has held up well. 4000 to 4200 rpm is the max rpm i get. i have had a clymer manual and a seloc, i prefer the seloc. check all the bellows on the outdrive for cracking if they weren't replaced. be sure to drain the water out of the motor during the winter. i change the lubes out every season. bookmark this forum, it is very helpful. now you can join in the discussions of what type of oil to use, wot issues, gimbal bearing noises, labor cost, and other issues that make you boat owner.

 

[Sharps-Nut]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

I have heard a boat is hole in the water too throw money in. I guess I may need a second job. Shift cables and bellows were listed on the invoice. Still lost on the trim meter wires. I will have a look and see tonight back in the back area and see if the post is more meaningful. Is trim meter needed. It does not have one now. Where is this gimble bearing grease zerk. I know I want that thing greased sound troublesom.

 

[Doug Durako]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

I ran the same motor and drive in a 1976 Cobalt for 860 hours with no problems. Change oil in motor and drive every 40 to 50 hours, or at least once each season. Manual will tell you all the specs and recommended intervals.<br /><br />Should be plenty of power to pull tubes, if you don't overload the boat with people and gear. From your speed and rpm range sounds like you have a prop that is pitched to pull skiiers. See if there are any numbers stamped on the prop inside rim as you look at the nut, or on the shank of the prop at the bottom edge of one of the blades.<br /><br />You will want a spare prop and know how to change it before you go too far. Also covered in the manual.<br /><br />Sounds like the boat has been taken care of. If you do not like messing with points, investigate the Petronix magnetic spark advance (search this forum for more info on Petronix).<br /><br />Good luck and have fun!

 

[Trent]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

Nope.. You really dont need a trim meter. I never even look at mine on my boats. Gimble zerk is about the three to four o-clock position on the starboard side of the gimble housing (outside of boat).

 

[biloxiriver]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

Sounds like the previous owner did a good job of keeping the boat up. I think the 165 hp 250 GM is great, ran an early 70s (73) Wellcraft with one for several years. Good power and speed, but a couple of key items to look at and watch are:<br />1. Transom rot; any flex and you will spin the coupling in your outdrive. I did this twice before having the transom checked and replaced, which fixed that problem. Cost me about $400 each time for a shop to replace the coupling. Rebuilding the transom was another $2,000.00+.<br />2. Exhaust manifold. If ran in salt/brackish water should be replaced every 2 - 3 years, even if you flush after every run. Exercise the bolts periodically so when you do replace them they will unbolt ok.<br /><br />One of the best things to me about the GM 250 is the ease of maintenance and repair. It is a basic engine. I would definately make sure and convert to electronic ignition if not done already. In many ways I regret having sold the old boat, but we move on. I now run a true inboard with a 302, and it is a great motor also. Am wrestling now with changing the exhaust manifolds on it though; been 3 years in SW and showing it. One thing I intend to do is at least every 6 months is exercis (loosen and retighten) the manifold bolts in order to ensure they will come out at replacement time. You do not need the trim indicator; trim down to take off, and set your running trim based upon the attitude of the boat after it gets on plane, use rpm's, and speed (best speed at lowest rpm) you will get the feel for it over time. Good luck and welcom.

 

[mercrewser]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

Those engines run forever. I used to cruise at 3000-3500 no problems.

 

[Sharps-Nut]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

Thanks for all who replied. I found the grease zerks for the gimble bearing and I would guess the pivot point on the outdrive. The boat has been fresh water only as far as I know. Being in Missouri and the history I was told I am fairly sure of it. Loosening and tightening the exhaust boalt sound like a good plan and one I would have over looked. Transom rot scares me to death but I think its ok, a buddy of mine went with when we test drove it. He has boated for several years and he did a lot of jerking up and down on the outdrive. My guess is thats what he was looking for. Thanks S.N

 

[Doug Durako]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

Sharps--traonsom rot will show in a variety of places. Any spider web marks on the fiberglass on the stern? These are hairline cracks that can be hard to see but they indicate stress on the transom or moisture working from the inside out. Also look for noticeable signs of repair and/or blisters in the gelcoat. Look inside the boat under the corner of the carpet back by the motor cover----that is where water usually sits and sits. If the previous owner had a good cover and took care of this boat, should not be a problem. A boat that age would be on its 3rd or 4th cover.

 

[rodbolt]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

hello<br /> sounds like you found a seet deal.<br /> the 250 inline was a tough motor but was never really popular. dont know why cause it worked very well. like trent said. ditch the trim meter. they are expensive to repair and maintain and fail quite a bit.<br /> good luck and hope ya have a wonderful boating experience but forget ya ever worked on cars, its a whole different ball game. how many car wrenches ever see a fuel starve problem at wot after 30 min of running?<br /> this is a precision high performance piece of gear, treat it as such and it will live. treat it like a car and you will have an expensive lawn ornament that causes divorces

 

[Sharps-Nut]

Re: New boater, Questions over 165hp 250 gm six, and merc outdrive

Thanks for all the good advice. I will take the trim meter back to bass pro shop. Rodbolt your right about being a different game realized that fairly quickly. Still hoping to learn to do my own repairs. Teacher salaries are sorta low and I get a kick out of getting dirty. Saftey and dependable was mostly what we looking for. Sharps-Nut