1971 Johnson 9.5 - found existing problem

[joho5]

Ok I am only about 3 months into this motor and I remember the guy telling me when he gave it to me that it had a new head gasket. (cylinder head gasket). Well now I see that sometime in the past one of the spark plug holes had been stripped out and they had added liquid metal and actually drilled it out bigger, then inserted some kind of threads that fit a spark plug and then sealed it up. They did a good job of making it look good, but those circluar thread reduction piece they put in there came loose and is actually stuck on the thread of my spark plug. Long story short, I am getting a new cylinder head. My question is do you always have to change the gasket when you do this, or only if it is bad. I know it is fairly new. Also, I will have to switch over the thermostat, is there any gaskets or seals in there that will have to be changed due to just removing and replacing?

thanks guys

 

[tashasdaddy]

Re: 1971 Johnson 9.5 - found existing problem

yes and yes. why put a used gasket on, and take a chance of having to do it over. gaskets are cheap.

 

[Vic.S]

Re: 1971 Johnson 9.5 - found existing problem

From your description the head has been fitted with a Helicoil SEE HERE fopr an example, or similar.

If there is no further damage it should be possible to fit a new one.


It is false economy to reuse gaskets. Definitely do not reuse a head gasket. It should be possible to fit a new Helicoil without removing the head.

There is a seal and a gasket associated with the thermostat. See the cylinder and crankcase diagram on the BRP parts website

 

[tashasdaddy]

Re: 1971 Johnson 9.5 - found existing problem

here is your head gasket http://www.iboats.com/Sierra_18_295...4802649--**********.550713650--view_id.173731

the thermostat seal is Brp # 310058 thermo gasket 309580

Brp Head gasket is 309612.

 

[joho5]

Re: 1971 Johnson 9.5 - found existing problem

From your description the head has been fitted with a Helicoil SEE HERE fopr an example, or similar.

If there is no further damage it should be possible to fit a new one.


It is false economy to reuse gaskets. Definitely do not reuse a head gasket. It should be possible to fit a new Helicoil without removing the head.

There is a seal and a gasket associated with the thermostat. See the cylinder and crankcase diagram on the BRP parts website

Is this a common procedure, because I definately dont have the equipment to do this, but I am not sure who I would take it to to do this. Plus when talking about labor costs, would it be better to just pay $110 bucks and have a brand new product? The large hole would have to be redone because the threads that are stuck on my spark plug wont tighten down.

thanks for the response, very useful.

 

[tashasdaddy]

Re: 1971 Johnson 9.5 - found existing problem

imho, helicoil is a band aid. it may or may not stick.

 

[joho5]

Re: 1971 Johnson 9.5 - found existing problem

imho, helicoil is a band aid. it may or may not stick.

obviously, because the one I have didnt hold. I dont know for sure what mine was fitted with, it could have been just a ghetto rig. I will try to unscrew that piece off of my spark plug and see what it is. I will take a pic and post it.

a new head is $110, and I am looking for a used one. Its a part that seems easy to put on, just held together by bolts.

When transfering the thermostat, would I absolutely need to buy a whole kit with thermostat and everything, or just use existing and replace the gasket and seal?

I am trying to stay somewhat on a budget. My wife tends to get aggravated when I am spending alot of money on the boat...haha

 

[mikesea]

Re: 1971 Johnson 9.5 - found existing problem

"I am trying to stay somewhat on a budget. My wife tends to get aggravated when I am spending alot of money on the boat...haha"
That is why my pholosophy is don't tell.No reason to upset the little women now,is there?
For the same reasons I'm not told how much their nail jobs cost.Frankly I see no logical reason to pay someone to file and paint her nails.I can do it in my shop,I have various colors,Johnson White,Evinrude Blue(in many shades)Mercury Black,Viper Red and many more.The savings could then be better used on ,important items .Like fishing rods(of course his and hers)or in your case maintainence items like your cyl. head so ,for sake of the family ,the boat runs safely.
That all said,my little woman dont read these forums or know my name here.
But most of all.I'm the BOSS.I'll buy a cyl.head when I want too.
If she does read this,its not me dear,

 

[joho5]

Re: 1971 Johnson 9.5 - found existing problem

Ha, well I got lucky today. While calling numerous places trying to get the part, raning from new $110 - $150 bucks, and about $85 used I ran across fairwinds marina. They had one in stock in the box brand new and he sold it to me for $70. I didnt hesistate, said just ship it to me. I have been informed this part is no longer available from Evinrude so I feel somewhat lucky to find a new one at that price.

thanks guys

Matt

 

[joho5]

Re: 1971 Johnson 9.5 - found existing problem

Hey guys, while I have the head off, what can I do to clean inside there?

I have never done this before and I want to take advantage of getting in there since I will be pulling the cylinder head off.

what is safe and not safe to use.

thanks

Matt

 

[mikesea]

Re: 1971 Johnson 9.5 - found existing problem

More Pholosophy.Since you shopped around.You now have 40-80 in savings to spend on fishing equipt.Its like getting money for free,
Seriously,visually inspect that there arent any giuges on the cyl.walls,clean the water passages around the block ,iF YOU SEE ANY CORROSION BUILDUP OR SAND ETC.Be sure to scrape any head gasket material from the surface of the block.New headgasket.A contraversial subject,but I like to coat the gasket with a lite coat of sealer.Its a good idea to chase the headbolt holes with a tap.Clean the bolt threads,spray the bolts with wd-40 or some kind of lie oil.BE sure to torque the head bolts to proper torque.Note that sometimes the torque spec.is given in foot punds or inch pounds.Dont confuse.Start on inner bolts working outward in a circular paattern,tighten in steps,dont go immediatly to max torque,break it down in 3-4 steps.DONT OVER TIGHTEN PLUGS.Good luck.glad u found your part.MIKE

 

[joho5]

Re: 1971 Johnson 9.5 - found existing problem

thanks...the carbon buildup is a bit different from the top of one piston to the other. The one that is closest to the carb is more of a satin regular buildup, the other is a bit more chunky. Not too bad looking, but I was just wondering if this indicates anything.

thanks for all the help.