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Mercruiser 1985 305 rebuild and cam questions

C

cass

New member
"Hello, I'm new to this site, but it looks like you guys know what you're talking about, so here goes. I have a 1985 Glastron 18.5 that was repowered with a 1991 Mercruiser 305, and an Alpha1 OD. It starts, runs fine, but if I shut it off, it won't start once it's warm. The previous owners used it a lot, long distances flat out (waterski races). I have tried everything short of a rebuild. I think my rings are fatigued, and once its warm, the tolerances change and I lose compression. I did a compression test, and it came in way low, all between 40 and 80 psi. Does my logic make sense? If I need to do a rebuild, I want to upgrade to a more torquey cam. Will I lose reliability? Is this a good idea? Does anyone have a suggestion for a cam? Last question, is the engine removal a huge pain in the ass? Sorry for so many questions, I'm a newbie. Any info would help. Thanks"
 
"Yep a new crate motor 5.7 wou

"Yep a new crate motor 5.7 would do nicely straight from gm. Or call your local chevy dealer maybe they have a 5.7 laying around some where.Then tranfer over the mani's risers and such. If they are still good that is.

Me i would install a new 500 dollar mani and riser kit comes with everything in one box gaskets and all, and some sites have it for under 500 saw one closer to 400.

If your starter is good transfer it over maybe a new one, if you have the money. Same for the alt."
 
"[b]"I did a compression t

""I did a compression test, and it came in way low, all between 40 and 80 psi."

Ayuh,... That motor is Beat...
Swap in a rebuilt 350,+ be Happy..."
 
"The boys are right on the mon

"The boys are right on the money. Given the age of the boat, I would check the condition of the transom, floor and stringers for rot first. They are an expensive repair; you may find it better to trash the boat if it needs wood rot repair unless you can do it.

If all the structural components are good then consider a complete "drop-in" engine. Just plug it in and go. You'll have all new engine components. They may also come as a reman. engine; not sure.

If you can do the work then the longblock is the way to go as Bondo said. Otherwise the cost of a drop-in and a longblock can become a toss-up due to cost of old transfer parts on the worn engine needing replaced.

Go w/a 350 Vortec MARINE RATED ENGINE."
 
this link is for a vacuum test

this link is for a vacuum test i dont quite understand this is not the same as a compression test thanks
 
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