# Yamaha F40 Zincs



## Smackdaddy53 (Dec 31, 2012)

No, I would buy new gaskets and remove the head to get it out. If debris starts building up behind it you will have a hot spot and possibly cook your piston(s).


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## mwolaver (Feb 6, 2014)

This is why I have been reluctant to remove mine. How many hours on your engine, please?


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## Smackdaddy53 (Dec 31, 2012)

I am about to replace all my hard brake lines on my truck with stainless and was researching line wrenches and prepping the line nuts for removal. A guy showed how he uses a can of keyboard duster turned upside down to “freeze” each fitting then uses a mini torch to heat it up. This is something I have never done, I always just heated fasteners up to break them loose. Freezing them first will cause more contraction then expansion when heated should help break fasteners loose better. I also like to heat a bolt up with a torch and let it cool a couple of seconds then spray penetrating lube on it and the cooling effect will draw the lube into the threads. If you spray it when the metal is too hot the lube will just burn off and not penetrate into the threads. A few blacksmiths I know use wax in the same manner but I never tried it.


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## ek02 (May 8, 2012)

I have about 380 hours on it, but it is a 2006 engine. I waited way too long to do this service. The bolts with the 10mm heads were hard to break loose, but I tapped them with a punch and they came loose. Just that one very small piece fell into the head water passage and the way the head gasket passages look, it may stay in the head. The decision is take a chance on breaking head bolts or leave the small piece at the bottom of the head. If you run into a similar situation as mine possibly use a shop vacuum or a hand held vacuum pump to remove it. Another thought is to use a flat 1/4" punch with heavy grease on it to try to snag it. All things I did not think about at the time.


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## Smackdaddy53 (Dec 31, 2012)

ek02 said:


> I have about 380 hours on it, but it is a 2006 engine. I waited way too long to do this service. The bolts with the 10mm heads were hard to break loose, but I tapped them with a punch and they came loose. Just that one very small piece fell into the head water passage and the way the head gasket passages look, it may stay in the head. The decision is take a chance on breaking head bolts or leave the small piece at the bottom of the head. If you run into a similar situation as mine possibly use a shop vacuum or a hand held vacuum pump to remove it. Another thought is to use a flat 1/4" punch with heavy grease on it to try to snag it. All things I did not think about at the time.


I just broke the fifth lower unit bolt head off on my Yamaha 70 and can’t drop my lower unit now. It happens even to guys that maintain their equipment. I thought the bolt was coming loose and it was just the head twisting off...


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## mwolaver (Feb 6, 2014)

ek02 said:


> I have about 380 hours on it, but it is a 2006 engine. I waited way too long to do this service. The bolts with the 10mm heads were hard to break loose, but I tapped them with a punch and they came loose. Just that one very small piece fell into the head water passage and the way the head gasket passages look, it may stay in the head. The decision is take a chance on breaking head bolts or leave the small piece at the bottom of the head. If you run into a similar situation as mine possibly use a shop vacuum or a hand held vacuum pump to remove it. Another thought is to use a flat 1/4" punch with heavy grease on it to try to snag it. All things I did not think about at the time.


I'm not far from 380, but my engine is a 2018. I will be at least inspecting them during the next service.


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## ek02 (May 8, 2012)

Order the Zincs and the gaskets that goes with them. You will at least need new gaskets if you inspect them. I got mine from Boats.Net. They are not too expensive. I feel for you Smackdaddy53. I have broken bolts as a car technician. I usually drill them as much on center as I can. I have a 1/8" dye grinder with a tungsten carbide bit to grind out the bolt as close to the threads as I can if it won't budge with an easy out. I use a tap to clean up what's left of the bolt, but then I have not used that process on stainless bolts on a lower unit. I hope you can get them out.


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## Smackdaddy53 (Dec 31, 2012)

ek02 said:


> Order the Zincs and the gaskets that goes with them. You will at least need new gaskets if you inspect them. I got mine from Boats.Net. They are not too expensive. I feel for you Smackdaddy53. I have broken bolts as a car technician. I usually drill them as much on center as I can. I have a 1/8" dye grinder with a tungsten carbine bit to grind out the bolt as close to the threads as I can if it won't budge with an easy out. I use a tap to clean up what's left of the bolt, but then I have not used that process on stainless bolts on a lower unit. I hope you can get them out.


Hard to drill the bolt out when the prop shaft is directly in line with it! I’m going to have to get my 90 degree Dremel attachment with a tungsten cutting bit on it.


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## ek02 (May 8, 2012)

We haven't used this boat and engine until yesterday. The small piece of zinc did not have any effect on the F40. We ran it almost 40 miles yesterday with no problem, thank goodness. The fishing at Flamingo was great. We caught 7 tailing Reds 6-7 lbs. plus Jacks, Snapper, Etc.


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