69 Mercruiser 165 inline six rare problem done everything please help!!!

[fngboater]

Re: 69 Mercruiser 165 inline six rare problem done everything please help!!!

well that explains why the valves were not closing all the way while running

 

[achris]

Re: 69 Mercruiser 165 inline six rare problem done everything please help!!!

Nice catch. Sorry none of us suggested it... Have fun on the water...

 

[Fishermark]

Re: 69 Mercruiser 165 inline six rare problem done everything please help!!!

I can see that it took a while to find because of: the broken paint around the screws on the timing cover, homemaid gaskets on the thermostat housing and the rear end cap of the manifold, 1 odd spark plug, new manifold gasket, etc.

Are you telling me that the shop that did the work gave it back to you as described above?

It's good that they took the time to get it fixed (if they did in fact fix it) - but it sounds pretty shoddy to me.

While you have the engine out and everything is easy to access and remove, you might want to think about doing the re-route of the cooling for the exhaust. I will do a quick search and post what I am talking about.

 

[Fishermark]

Re: 69 Mercruiser 165 inline six rare problem done everything please help!!!

Here's the post I referred to above: Exhaust modification

 

[Fed]

Re: 69 Mercruiser 165 inline six rare problem done everything please help!!!

I expect to get roasted but I don't believe weak valve springs were causing your problem Matt, anyway I hope it's all good now.

 

[Matt Braley]

Re: 69 Mercruiser 165 inline six rare problem done everything please help!!!

Yeh, it really ran like they timed the new cam wrong. Now it runs great!!! And I did get a new set of springs installed out of the deal. I also put in a new flapper in the exhaust pipe while the engine was out the second time. Now the fun stuff: acc. batt, aft cover, interior lighting. Before the not fun: gel coat repairs, water soaked foam, fresh plexiglass.

 

[telstar1]

Re: 69 Mercruiser 165 inline six rare problem done everything please help!!!

no way in he.. valve springs would cause that imo.Maybe if there was no valve spring at all....Problem was something else I blve.

 

[Ronlee]

Re: 69 Mercruiser 165 inline six rare problem done everything please help!!!

Back the rocker arms all the way off of 5 and 6 get a compression tester and remove the check valve in the extension hose. put air pressure on 6 and listen to the exhaust and intake. If you hear air hissing you have a vale problem, if you hear air coming from 5 you have a blown head gasket.
Also try and back the valves off. MArine high lift cams like the 165 only need to go down 1/2 turn after the click goes away. The valves may be floating slightly due to being too tight.