cant get the cylinder head cover off

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dmorray

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im trying to get the cover off the cyl. head of my 25 hp evinrude, i broke one of the bolt heads off in the process, ive tried to use a bolt extractor and that didnt work, short of completely drilling out the bolt and re-tapping,....are there any other options that may work?
 
rolmops

rolmops

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Re: cant get the cylinder head cover off

See if you can get the other bolts off and remove the head.Chances are that you will see the broken off part protrude and if you heat it up a bit it and set a vise grip on it it may come loose.
It is a good idea to apply a bit of heat to the bolts that don't want to move.
 
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dmorray

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Re: cant get the cylinder head cover off

well. i do have all the other bolts out, but the bolt with the broken head isnt sticking out at all, it is recessed into the head cover, i even have managed to break the cover loose from the gasket and head all the way around except in the spot where the broken bolt is. i thought i might be able to pull the head cover loose with the bolt still in there , but it wont budge, i dont know if the threds are continued into the cover, or if they stop at the head itself,....or if its just really stuck , and thats why it wont move. i just dont want to force anything and screw it up even more.
 
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tx1961whaler

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Re: cant get the cylinder head cover off

dmorray said:
well. i do have all the other bolts out, but the bolt with the broken head isnt sticking out at all, it is recessed into the head cover, i even have managed to break the cover loose from the gasket and head all the way around except in the spot where the broken bolt is. i thought i might be able to pull the head cover loose with the bolt still in there , but it wont budge, i dont know if the threds are continued into the cover, or if they stop at the head itself,....or if its just really stuck , and thats why it wont move. i just dont want to force anything and screw it up even more.
Click to expand...

Let's get some terms cleared up (for me, anyway):
Are you taking off the cylinder head (#14) or the cylinder head cover (#53)?
convert
 
tashasdaddy

tashasdaddy

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Re: cant get the cylinder head cover off

when those get hot enough, corrosion forms around the bolts, i had an older 18 we never got the head off. try some heat to area of the broken bolt, then pry but careful of the mating surfaces.
 
rolmops

rolmops

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Re: cant get the cylinder head cover off

Before using heat and/or force, do double check that you really did get all bolts out
 
T

tx1961whaler

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Re: cant get the cylinder head cover off

If it's only 1 bolt, then drill it out.
Use a center punch to start in the center of the bolt, then use a small bit to start. I like using real cobalt bits for this type of stuff.
I try to set a depth gauge on the drill so that it can't drill into the engine block. Once the bolt is drilled out enough, it will weaken enough to snap.
Don't try to use an EZ out extractor; it will just break off and then you'll have big problems.
 
H

HybridMX6

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Re: cant get the cylinder head cover off

I would do as suggested by rolmops. I'd double and triple check all the bolts are out, then if so, heat it up and see if you can't pry it out some with a large screwdriver or chisel. Go gently though, you do not want to mar the surface. Once it starts to break free it should be easier to get it off. Once off, there will be a piece of the bolt sticking out. I'd try some serious penetrating lube and heat, then some vice grips. It may even be possible if you have an impact driver and a Dremel to grind a single notch into the end of the bolt, big enough for a large flathead screwdriver bit in the impact driver, and give it a few good whacks. Worked for me once on a very similar problem.
 
samo_ott

samo_ott

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Re: cant get the cylinder head cover off

I concur. Don't use an extractor. It'll break off and make it impossible to remove. drill it out. It's not as hard as one thinks. And I have heard to use left handed threads but I have never found them or tried it.
 
robert644

robert644

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Re: cant get the cylinder head cover off

I've had this problem on my 15's. I agree with the other posts, use a cold chisel and hammer it in there from the outside edge. I've drilled them out as well. I had to use a hand-crank drill, and ended up drilling and tapping for the next size bolt (on the cylinder head). Worked fine, if not ugly.

I think someone said to me that these castings were designed to accept one size larger bolt for this very reason. But that was almost 2 decades ago, and I haven't messed with an engine for the last 6 years.
 
DGartzos

DGartzos

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Re: cant get the cylinder head cover off

Use a center punch to start in the center of the bolt, then use a small bit to drill through and work out a hole 2/3 bolt's diameter.

Then heat on head outside and around bolt and air cool right direct in bolt hole. Give it time and tries, it will free up.
 
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dmorray

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Re: cant get the cylinder head cover off

thanks for all the great replies everyone,....i finally got the bolt out,......i just welded another bolt head onto the existing bolt and worked it (veryveryvery) slowly and it finally came free!!! (also used alot of pb blaster)
 
samo_ott

samo_ott

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Re: cant get the cylinder head cover off

Excellent news :) And it sure was satisfying when you got that little beastie out, wasn't it! :)
 
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dmorray

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Re: cant get the cylinder head cover off

yes, very satisfying!!!! the motor is running better than before, i cleaned the carbon build up off of the end of the pistons and the exhaust ports, put a new thermostat, gaskets, spark plugs, re-tuned the carb., and she's purring like a happy kitten,....im also getting about 2.5-3 mph more out of the motor at top end, who would of thought???!!!???!!!!
 
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tx1961whaler

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Re: cant get the cylinder head cover off

You probably know this, but make sure to re-torque the head bolts after running it a bit
 
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dmorray

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Re: cant get the cylinder head cover off

i did know that, but completly forgot to do it, we just got back from a scalloping trip this weekend where i put apprx. 6 hrs. on the motor, i defi. need to re-tighten the bolts after that, the motor was under alot of strain from the 2-3 ft. swells of the open bay, thanks for the reminder, i'll go do it right now!!!
 
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