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

[Pete104]

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

You claimed earlier, water in cylinders & oil. My question still stands. What manifold are you using?
The original version (1969) has a plate & gaskets to make it intake/exhaust manifold. The last version is 1 piece done by casting the intake/exhaust from each other.
Have you tried running the engine without water to it? Just to see how it runs. Long hose off at thermostat hsg.
Is the engine somewhat level when your running it? The front end not real high because of a driveway or hill.

 

[dan t.]

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

Cam timing should not affect only # 5 and 6, they do however share a common intake port on the manifold, I suspect a vacuume leak. Spray around the head to manifold joint with brake clean or penitrating oil while idling to see if it smooths out.

 

[Matt Braley]

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

Thanks guys, that gives me a couple of great ideas to try

 

[dollarten]

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

Thanks guys, that gives me a couple of great ideas to try

Here is a long shot but ,,, When the engine is running and with the air silencer off , try shooting some gas with an oil can with gasoline in it with the engine running . This would rule out the idea of a plugged up idle circuit on the carburetor . If the engine revs up a little bit , you have carburetor problems. This engine runs with a two bbl. ( barrel) and maybe one of the idle circuits is plugged .Like I said , something to eliminate in the search

 

[Matt Braley]

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

Thank you for your thoughts and ideas. I was not able to get a riser gasket today so I worked on other areas of the boat. I will do these tests asap. Pete, my manifold looks just like the ones I see in every one elses pics. I would call it a log style. You said 4 piece, is that 1-log, 2-riser, and then 2 caps? Looks like they gave me an automotive manifold gasket because its rusting already. I want to install riser and check for air leaks before I pull it. I like the idea of running it for a second without water but I just put a new impellor in it and would hate to loose that. Anyway, I will update soon thanks again, Matt

 

[Matt Braley]

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

Today I tried running the engine without water(capped off hose to keep it on my impellor)but no change. I sprayrd around the manifold to head gaskrt and no leak. I have my engine level, new riser gasket with good shiny metal on both surfaces. All I gained is finding out that my #2 cyl. is not helping either. So this thing is only running on 1,3,and4 with no help from 2,5,and6. I pulled the dist out a couple more times to try it a couple of different places but no difference. Adding gas or closing the choke while running takes away from rpm, does not appear to be starving for fuel. The manifold to head gasket started rusting in the first hour so I suspect it was automotive but shoud'nt that be the same other than the lack of graphite or stainless? Please give me some more ideas when you can thanks, Matt

 

[dan t.]

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

Check the valve setting, it is done as follows, remove the valve cover, start the motor and let idle, starting at the front, one at a time back off the rocker arm until it rattles,turn down until it is just quiet and go on to the next one. When all the valves are at 0 lash shut off the motor, turn each one down 3/4 of a turn, let it sit for 10 minutes while you reinstall the valve cover. Start it up and see how it runs. One other idea, check the point setting, if they are set too tight they may not be breaking on the cylnders that are missing,the lobes on the breaker cam may be worn more on those cylnders. I believe the point gap is .016. Good luck.

 

[Matt Braley]

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

I have the ignition upgrade(petronix) and full valve movement, great compression(131-141). I will adjust valves but need those oil deflectors. I don't see any difference in the cylinders that fire(1,3,4) and those that don't(2,5,6).

 

[Fishermark]

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

Try swapping some of the wires if you have enough length. I don't mean to change the firing order, but take the wire from one of the cylinders that is firing well, and put it on one that isn't. Then run it and pull the wires one at a time again and see if the problem moves with the wires or stays with the cylinder.

 

[Matt Braley]

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

The problem stayed with the cylinders. But thank you, it gave me something else to try. The wires are new but that dosen't mean they were good. I've moved the plugs around too. I ran it with the rubber exhaust boot off to make sure that it was not plugged.

 

[FreeBeeTony]

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

Are you 100% sure you have spark at those cylinders?

 

[Matt Braley]

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

Yes, I have been jolted myself a few times. I've torn a couple boots up pulling them off so much. I've placed the timing light on every wire, gounded the plug outside the block to watch it. I pulled 2,5,6 right out of the top of the cap a cranked it(ran the same) then I could try different orders with the other wires. Nothing, but I did get good spark arching from the cap to leads.

 

[fngboater]

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

maybe the shop put a 4cyl head gasket on it. lol try doing a resistance test on your plug wires. are you sure you have the correct rotation on the distributor ie. clockwise firing order or vise-versa. ? pull the cap off and crank the engine to make sure. maybe a cracked distributer cap or just plain faulty from the get go ?? (ive seen that before) valve lash too tight leaving valves open??

 

[sschefer]

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

All things being equal, a good marine mech rebuilt your motor so he should be able to tell you what's wrong with it. I suspect a vaccum leak either at the carb base or intake manifold/head. Could be a cracked intake that cracked when you blew cold water into it from the leaking riser.

 

[Matt Braley]

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

I am going to get it in to the engine builder in a couple of days. I would have already but they had a couple boats coming in. But with me completely beaten over this I stopped at a marine mech. outfit on the way home to run it by them. The guy there also believes that the valves are to tight. I said"but I have great compression on every cylinder", but he explained that turning it over for a compression test is one thing but when the engine starts the oil pressure builds and makes it tighter. This is why I read of doing it while running. I'll have to make a way to redirect the squirting oil and try this tom. He also has a complete motor like mine sitting out in the rain for years. Don't cha know the first thing I did was walk up and look at that firing order, sure enough, 153624....no breakthrough

 

[achris]

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

Couple of things.. The firing order cast on the block needs to be verified visually against the valves opening. Also squirting oil from the rockers (comes up from the lifters via the push-rods) can indicate the lifters are faulty. Faulty lifters could be not opening the valves on the affected cylinders properly...

Chris....

 

[dan t.]

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

An old tin valve cover with a slot cut out of the top works well for setting valves, setting just to 0 lash while running also cuts down on the mess. the 3/4 turn set can be done with it turned off.
achris, oil squirting from a rocker arm is a normal state of affairs on a chev engine.
I also thought of distributor rotation, you can have the firing order correct for the opposite rotation and it will run but but not worth a pinch of coon s#%t. Good luck and dont dispair, we will find this problem.

 

[Matt Braley]

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

Thank you guys so much for this input. The push rods were not replaced and this engine ran rough before and after the rebuild. However the head gasket was blown in 2 places between cylinders. It and the block got decked quite a bit and needed it.

 

[Matt Braley]

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

well I through in the towel and yanked the engine back out. I dropped it off with the engine shop and they will run and tune it there. I fear it will be something simple and stupid that I've missed but lets see. Anyway I'm putting a new flapper in and gonna work on the appearence of this old Aristocraft in the meantime. Thank you for all your helpful input and I will post the results of their findings.

 

[Matt Braley]

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

Well I got the engine back today. He said it was weak valve springs. He also said it took a while to find, apolagized for not testing the tension, and bought me a new set that he bought and installed for free. 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. At this stage all the issues should have been found. They ran and timed the engine. Now I hope to have posts of all the wonderful trouble free winter hours I'm getting. Thank you guys for all your help. I really did try every suggested test.