Mercruiser 3.0l 145hp v 135hp

[oGaryo]

Hi, I've been pondering this for a short while now and not really come up with a definitive answer.. does anyone know the difference in specification between a Merc 3.0l 145HP lump and the standard 135HP version?

different head maybe? alternative tuning components? both? any more differences?

Are there any engine guru's out there able to offer me a definitive statement as to the differences including what I should watch out for in the standard service manual when setting up a 145HP variant e.g. would the 145HP still be set at 1 degree BTDC for timing or indeed, 1 degree ATDC on some of these engines.

Many Thanks Gary

 

[Matata]

Go to themarinedoctor.com tell him I sent you! What he doesn't know.....Let me know how you get on!!! matata

 

[William_H]

Mercruiser

I am not really able to help but I imagine it is like car engines a little tweak here and there and claim a few more horsepower. I can only suggest the safest source of maintenance information is from a manual specifically for the 145 HP.
Our club rescue boat has I think one of these. 4 cyclinder Mercruiser. A few years back someone got a deal to replace the engine with almost the same thing. What really dismayed me was that for 10 years or more car engines were all fuel injected and the brand new Mercruiser still had a carburetor. With the difficulties of starting cold auto choke and all that horrible old stuff. I really though a new engine from 3 or 4 years ago would have fuel injection. A friend has just bought a Mercury 6cyl (250) outboard with all the fuel injection etc etc it is so sweet by comparison. olewill just waffling

 

[oGaryo]

thanks guys.. swings and round-a-bouts I guess.. broadly speaking old tech = cheap and maintainable.. new stuff = merc tech and expensive.. I've purposly gone for the former as I want to learn about the engines for a couple of years to become competent at general maintenance on land and importantly, whilst bobbin about in the ogin.

The reason for the question is I'm a bugger for tweaking and refining settings to try and get the most from the setup.. not understanding the difference between the engines makes me think I may adjust to the manual and actually make things worse if I'm not careful.. I'll continue to try and find a 145hp manual as the one I have is for the 135hp

cheers Gary