[Road Head]

I recently acquired a 94 21' Chaparral inboard/outboard with the 5.7L Mercruiser and has a Mercruiser lower unit. Boat runs great. We have had it out on the water for a test run, everything works properly. I do not have any service records for this boat. I searched this forum some, but havent had any luck with exactly what I am looking for. I want to know what parts should be serviced, what should be replaced, etc. An example, the impeller. As far as I can tell, it should be replaced every couple of years, and since I dont know when it was last done, I may as well go on and do it. Also, my ujoint bellows is kind of dry rotted. No holes or anything, but it definitely doesnt look new. I am just looking for what parts should be replaced and/or inspected as part of a standard preventative maintenance plan.Thanks for your help!

[WillyBWright]

If you trailer your boat, you can maybe hold off on that bellows job. If it's gonna be moored, Do It! Parts are slightly expensive, but labor is a killer. If you replace one, replace all plus the water hose, shift cable, and trim senders. That way you shouldn't have to worry about them for several years. They're all rubber and rubber rots. If one is rotton, the others aren't far behind.Take a look at the adjustable motor mounts. Sometimes the lower nut loosens and throws the engine/drive alignment off. Screwing it back up until the bracket is tight against the top nut frequently brings it back into alignment. Make sure your battery connections are clean and tight. Use a pliers on those wingnuts! If the battery is older than 3 years, strongly consider replacing it.Right now I'd change the sparkplugs and rotor. Change the oil and filter. Change the gearlube. Rebuild the water pump. Grease the Zerks. Change the spin-on fuel filter and clean the one in the carb. Replace the belt(s) and keep the old one(s) for spare. Remove the prop to check for fishline on the shaft and grease the shaft before reinstalling the prop. Most of that is pretty inexpensive if you do it yourself.Once you know everything is in order, then consider those bellows. At the same time you can grease the U-joint zerks and splines, and check the gimbal bearing, and engine alignment.

[waterone1@aol.com]

At 12 years old, I would be looking at the exhaust manifolds and elbows, pricey to replace, but once they go, they can take an engine out quickly.

[Spyder208]

waterone 1, I also bought a used boat, 1991 Seaswirl OMC 454, what do you mean check the exhast manifolds? Remove them and check passages? Or see if they leak? Does this apply to all boats or boats run in salt water? The boat I bought has 173 hrs on it, compression is 170 lbs all cyls. Can you recommend anything else to check? Thanks.

[whywhyzed]

Manifolds must be primarily a salt water casualty...My OMC rear riser manifolds are 22 years old- the water passages have no corrosion to speak of -risers and gasket surfaces looked new when i took them apart 2 years ago.. couldn't get any scale out of them...but I am still going to pull risers and do a visual again this year on them

[waterone1@aol.com]

I don't know a-lot about OMC's exhaust manifolds and elbows, other than they are very different than modern mercruisers. As for the Merc's, Salt water will tear them up much faster than fresh water, but even in fresh water 12 years is definetly time to pull the elbows and look at the mating surfaces. Gently scrape off the gasket material and make sure you have nice shiny metal, about 1/4 inch thick around all of the passages. Look down the exhaust passages and make sure there are no rust trails. This is easy to do, the new gaskets are cheap and it will provide you with piece of mind. It could also save your engine.

[Road Head]

Thanks for the advice everyone. I ordered a Seloc manual, and may have access to the Merc manual through a friend. I am more of a do it yourselfer, its fun and you learn something new.

[fireship1]

The two best things that you need to have when servicing your boat is a manual and this forum! Post questions if you get stuck, if you don't know, or if you are curious about something. You will get answers! Good luck and keep posting!