problem after headgasket replacement

rpatton · Sep 16, 2012

hi guys
I am back again seeking some possibles answers to another problem. the other week I had a headgasket blow on me so i replaced it with no issues and it fixed the problem with water in the cylinders. that being said i thought while i had things apart i would give it a tune up, i replaced the plugs wires cap and points. since i did all of this the motor is very hard to start cold and even harder to start after it is hot and sits for a little while, to the point of killing the battery and when it does start itsputters for a few seconds then runs and idles fine. this is what i did, valves where set with the running method by loosing the adjustment until tapping was heard then tight until itstops taping then 1/4 turn more. tune up was set with duell at 32 and timing at 4 deg advance, both should be corect right? I sould also ad the motor has always been a good starting motor with just a tap of the key. does any one have any ideas where to start , at this point i do not know if it is a valve , point or carb problem . the motor is a OMC 3.0 and is a 1985. sorry for the long story just wanted to give a back round.

hayward6 · Sep 16, 2012

Re: problem after headgasket replacement

Since so much was changed, all you can really do now is check everything. You didn't mention how it runs once it is started... does it run like a champ, or does it suffer at all stages? I would start with a compression test just as a quick piece of mind for the valves being at least close to correctly adjusted. The problem I have with the running method is that while the valve covers are off it's really hard to distinguish between rattling and quiet especial on an engine of that age... Also due to the age you may have to turn the rocker down until the valves never seat before quieting it completely... do a compression check on each cylinder to see if that's the case. Follow that up with a timing check and see where you are. When you did the head gasket, did you do both sides? Did you get all the torques right? Trouble starting can also be as simple as a forgetting to tighten up a fuel line when you reassembled... double check everything you did. Let us know how you make out, love to see this through

rpatton · Sep 16, 2012

Re: problem after headgasket replacement

hayward6 said:
Since so much was changed, all you can really do now is check everything. You didn't mention how it runs once it is started... does it run like a champ, or does it suffer at all stages? I would start with a compression test just as a quick piece of mind for the valves being at least close to correctly adjusted. The problem I have with the running method is that while the valve covers are off it's really hard to distinguish between rattling and quiet especial on an engine of that age... Also due to the age you may have to turn the rocker down until the valves never seat before quieting it completely... do a compression check on each cylinder to see if that's the case. Follow that up with a timing check and see where you are. When you did the head gasket, did you do both sides? Did you get all the torques right? Trouble starting can also be as simple as a forgetting to tighten up a fuel line when you reassembled... double check everything you did. Let us know how you make out, love to see this through

Thanks for the reply . to answer your question the motor runs great ounce it is running all the way to wot. after i did it and saw i had a problem i reliesed i did to much at ounce. compression is good now with 125 in all four cylinders. just to correct you this is a 3.0 which is a 4 cylinder. i should have checked the gap on the points before i removed them , but would the gap give me my problems , i am set in the middle of the scale of 31 to 34 and i am at 32 to 321/2.

Levinz11 · Sep 16, 2012

Re: problem after headgasket replacement

How does the fuel system look? I think you have the ignition side covered.

rpatton · Sep 16, 2012

Re: problem after headgasket replacement

The carb does have some seapage around the base plate and top plate to body gaskets but not bad do not see any standing gas. Fuel could be the problem but i did not touch that in the rebuild and it ran great until i messed with it so i am leaning towards something i screwed up

Silvertip · Sep 16, 2012

Re: problem after headgasket replacement

Valves are NOT adjusted 1/4 turn down from zero lash. They are turned down 3/4 turn after they quiet. If you cannot distinguish between a clattering lifter and one that is not then you should not be using that technique. Wear is not a factor on an adjustable valve system. The only wear issue would be a lifter that has collapsed and is no longer functioning and as such would be impossible to properly adjust. If the engine ran ok up until the point you did the repairs, then there is no reason to suspect anything other than what you did as the cause. On hot starts are you using opening the throttle (using the fast neutral idle function)? Did you mess with the choke linkage or choke adjustment during this process?

rpatton · Sep 16, 2012

Re: problem after headgasket replacement

Actuly now that you mention it my friend broke the tube from the manifold to choke so he open the ajustment up all the way then it did not start rightso we closed ot up some. What would the ajustment procedure be and i will replace the tube . That could be my problem.

Levinz11 · Sep 17, 2012

Re: problem after headgasket replacement

rpatton said:
Actuly now that you mention it my friend broke the tube from the manifold to choke so he open the ajustment up all the way then it did not start rightso we closed ot up some. What would the ajustment procedure be and i will replace the tube . That could be my problem.

Well there is your cold start problem.

rpatton · Sep 17, 2012

Re: problem after headgasket replacement

Kinda what i thought it might even be my hot start problem. Question is how do i ajust the choke to the correct setting.

hayward6 · Sep 17, 2012

Re: problem after headgasket replacement

rpatton said:
Kinda what i thought it might even be my hot start problem. Question is how do i ajust the choke to the correct setting.

The choke stove isn't to terribly picky. All it does is draw air through a hose that goes through the manifold. As the air warms up that warm air manipulates the coil spring and the spring opens up the choke shutter. Personally If mine was giving me any trouble I would haul it off completely... I just don't get on the boat when its cold enough to require the choke. But to fix it all you need to do is buy a replacement or repair stove kit, or get some fuel line and bend a new pipe up yourself, then just attach it to the manifold opening and make sure air can pass through it.

If you want it done right, go with the replacement choke stove hit, they're inexpensive. To test it as a potential problem though, just run some line, or patch up what broke with some goo

rpatton · Sep 17, 2012

Re: problem after headgasket replacement

Thanks i can repair the pipe easily but how do i ajust the choke dial from when my friend loosened the screws and just cranked the buterfly open. Can i just open the throttle and ajust the butterfly until it is just about closed while not runing or is there a special way to do it and get right

hayward6 · Sep 17, 2012

Re: problem after headgasket replacement

Oh sorry I didn't see that the adjustment was thrown off. You should be able to get it close by adjusting it so it's just closed while cold. Give it a go and report how you make out... Someone other than me might be able to better help you with the adjustments, but that should get you close.

*Edited to correct an error*

rpatton · Sep 17, 2012

Re: problem after headgasket replacement

Ok now i am confused. You want me to set closed when it is hot? I thought when it is hot it should be completely open

hayward6 · Sep 17, 2012

Re: problem after headgasket replacement

rpatton said:
Ok now i am confused. You want me to set closed when it is hot? I thought when it is hot it should be completely open

Yep, you're right. I just typed that wrong

Silvertip · Sep 17, 2012

Re: problem after headgasket replacement

You NEVER adjust an automatic choke on an HOT or even WARM engine. You adjust it on a stone cold engine. You loosen the three disc screws and turn the disc so the choke begins to open. You then go the other way so the choke just barely closes. tighten the screws and you are done. That adjustment requires that the rest of the items in the choke system be free moving and that the choke housing and spring are getting heat from the stove. When the engine is fully warmed up the choke plate should be standing perfectly vertical. DO NOT ADJUST FOR THAT. You adjust the choke at the CLOSED position COLD. If that adjustment is correct the choke will open fully (again provided everything is in place and operating properly). You cannot adjust for worn or missing parts.

rpatton · Sep 18, 2012

Re: problem after headgasket replacement

thanks for all of the replies , i was just unsure if i should ajust to the closed position or slightly open, now i know thanksagain . i will certinaly give it a try when i am down at the boat next week.

Silvertip · Sep 18, 2012

Re: problem after headgasket replacement

rpatton said:
thanks for all of the replies , i was just unsure if i should ajust to the closed position or slightly open, now i know thanksagain . i will certinaly give it a try when i am down at the boat next week.

Remember -- adjust it for just barely closed. If adjusted to tight it will run very rich during start up.

rpatton · Sep 18, 2012

Re: problem after headgasket replacement

Got it thanks

problem after headgasket replacement

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