temp sensor threaded shaft broke off in cyl head...

[rjcress]

While re-installing the temp sensor in the cyl head the temp sensor body snapped off of the threaded cylinder that goes in the cylinder head. :facepalm::facepalm:

Any thoughts on how to get it out without removing the head?
I don't mind removing the head, but this is a fresh rebuild from SES and I don't want to invalidate my warranty.

I tried to back it out with a screw extractor, but the sensor material is too soft... the extractor just kept digging in deeper and was about to get into the cyl head threads.

I'm out of ideas, but thought I'd see if anyone else has any before I do something stupid (something else, that is)

 

[rjcress]

Talked to Tom at SES and have a plan. I will:
-drill out as much of the temp sensor as I can from the hole with a bit slightly smaller than the final intended hole size.
-use an 1/8" pipe thread tap to restore the threads
-use compressed air to blow any debris out of the water channel
-install a new temp sensor with teflon tape... this time, only hand tight plus a 1/4 turn with a wrench.

 

[kicker]

Hope it works for you, sounds like it should. I would suggest to run it on the hose after you have it fixed and hopefully all the brass remnants flush out. I am not sure how big the chunks of brass were that fell in, You might want to take the calibrated water fittings off to make sure nothing got lodged in the opening. Those openings are not that big.

 

[Robj]

I would try a different type of easy out, I have used the spiral type when I broke in the aluminum oil fitting for the rotary valve and it worked fine. If't that fails, you can put grease on the tap to try and catch the cuttings and prevent them from falling into the water jacket.

Good luck!

 

[68ragtop]

Is the engine in the ski? If not, lay it on its side when you drill it out, & have somebody hold a vacuum cleaner hose next to the bit. You'd be surprised How much of that will get sucked away. Even if its in the ski, it might help some.

 

[rjcress]

Is the engine in the ski? If not, lay it on its side when you drill it out, & have somebody hold a vacuum cleaner hose next to the bit. You'd be surprised How much of that will get sucked away. Even if its in the ski, it might help some.

Engine is out and this is great advice. Thanks! :thumbsup:

 

[LouDoo]

I would just take the head cover off, 9 times out of 10 the "O" rings and gasket can be reused. That way you will know that no shavings are in the block.

Lou

 

[Guest_User]

holy smokes, how did that happen, overtightened it?

is the threaded portion above the surface of the head cover?

I`m pretty sure the material is brass and very soft, possibly you could have taken a small pic, tiny chisel, or very small blade driver and collapsed the threaded broken piece, and out it comes without destroying the threads in the head...

 

[rjcress]

holy smokes, how did that happen, overtightened it?

Yep. I was trying to finish putting stuff back on the engine before work this morning and was in a hurry. Had I slowed down to think a bit this wouldn't have happened. :facepalm:
However, I did take time to note in the manual that this part should be secured with Loctite 518... which I used. :facepalm:

is the threaded portion above the surface of the head cover?

Nope.

I`m pretty sure the material is brass and very soft, possibly you could have taken a small pic, tiny chisel, or very small blade driver and collapsed the threaded broken piece, and out it comes without destroying the threads in the head...

Interesting idea. I'll try this before I resort to drilling.

 

[Guest_User]

Yep. I was trying to finish putting stuff back on the engine before work this morning and was in a hurry. Had I slowed down to think a bit this wouldn't have happened. :facepalm:
However, I did take time to note in the manual that this part should be secured with Loctite 518... which I used. :facepalm:


Nope.


Interesting idea. I'll try this before I resort to drilling.

the problem with an easy out or reverse thread extractor is that it puts outward pressure and expands the broken part as it digs in when the material is soft, brass into aluminum you have to be careful in how you get this out...

518 is anerobic sealant.
a good thread sealer like

or ARP thread sealer is a great alternative...

 

[rjcress]

518 is anerobic sealant.

I thought it was odd, but the manual said to use it.

 

[Guest_User]

I thought it was odd, but the manual said to use it.

518 is an anerobic sealant and room temperature cures in the absence of air...

I personally think BRP over uses this type as there are many new products within the last decade that can perform the job equally if not better... I don`t used the 518 to seal the venturi nozzle to pump. I`d rather use something like 1211 and a very good RTV.
518 can be a PITA to clean...
Don`t get me wrong it does have it`s perfect uses, like when sealing the tail come on the jet pump...

but here`s a little info:
http://tds.loctite.com/tds5/docs/518-EN.pdf

 

[griz400]

they sell a wrench, called an inside wrench at plumbing stores, and home depot, it may work -- http://www.globalindustrial.com/p/t...mpaignId=T9F&gclid=CKGfu7-eh7YCFRGqnQodC14ADw -- i used to remove a shower head pipe in bathroom, works slick
if its too big, grind it down to size, its cheap !!

 

[rjcress]

they sell a wrench, called an inside wrench at plumbing stores, and home depot, it may work...

Thanks Griz. I had never heard of one of these. I'll have to pick up a set.
I tried something that looked like this:
http://www.globalindustrial.com/p/t...lt/spiral-screw-extractors-irwin-hanson-53407

Because of the spiral it kept pulling itself down into the soft brass to the point I was afraid I'd chew up the threads.

I ordered a pipe tap to rethread the hole, so maybe I'll try the screw extractor again, since I can re-do any damaged threads.

 

[howie099]

Take it off and get it fixed right don't want to worry about shavings in the engine. If can't get it out without messing up the head off to fleBay for another one. They sell them cheap if need be.

 

[rjcress]

Take it off and get it fixed right don't want to worry about shavings in the engine.

I'm new at this, so y'all (that is Southern for "you guys" or "yous guys") please check my thinking on this...
In my .pdf copy of the 1996 Sport Boat manual there is a 787 cooling system diagram on page 05-02-5. It is labeled in French, which, in spite of my high school French teacher's best efforts, I can't read ... at all. Not even a little bit. But the color coded picture appears somewhat self explanatory.
As I understand it, the temp sensor only extends into the water channel in the head. There should be no danger of getting shavings in the cylinders (as long as the spark plug holes are plugged), only in the cooling system. The temp sensor is located beside the water outlet on the head, which leads directly to the transom water outlet. So, if there are any shavings that I can't blow/flush out of that cavity, they should pass out of the system without incident, since the only parts of the water system after the temp sensor are the head water outlet, the hose, and the transom water outlet. As long as I don't lose any shavings big enough to clog or damage anything on rather direct path out of the boat, I am not seeing much risk in doing as Tom suggested (drilling & tapping the temp sensor hole to install new sensor... then blowing out the shavings with compressed air).

Pics showing water flow in head:
Page 05-02-2 of the manual
and
http://www.seadooforum.com/showthre...he-quot-787-quot&p=19300&viewfull=1#post19300

I certainly don't want to start a new thread later about how I have other stuff to fix because I failed to take the head off while fixing the temp sensor, but I don't care to invalidate my warranty or take anything apart that doesn't really need to be taken apart. A couple of folks have been kind enough to advise that the "right" way to do this involves removing the head. I'm just not following that logic and am afraid I might be missing something.

Thoughts?

 

[kicker]

As long as no shavings are bigger then the small brass calibrated nipple holes going into your exhaust you will be fine. After you have it fixed run it on the hose to flush it and stick your finger inside the exhaust to make sure water is coming out of the small hole. You might want to check the nipple going to your tuned pipe as well. You are correct that nothing will get into your motor, just the cooling channels.

This is the nipple from the inside of the hull, mine was clogged as you can see.

 

[Coastiejoe]

Are you able to remove the exhaust and then flush the cooling system with a hose?

I would need to look at schematics to see where and how the water flows. But if you could flush the engine without the water entering the the combustion chamber, then it would be worth it I think.

 

[LouDoo]

Here wego.

Lou

 

[Coastiejoe]

Nice diagram, thanks Lou,,,

After looking at it, I think I would remove the exhaust, turn the engine upside down, hook up water to what would be the left rear water inlet of the head and let it flush out. Remove spark plugs if they are in there as this would let any water easily run out of the cylinders if it gets in through a valve.

I am 50/50 on either blocking or leaving open the right rear water exit. If blocked, you may push a shaving to a location that it may not come out until you run it in the water. If unblocked then you have the potential of the shavings going in both directions. As in the direction of the exhaust and also through the cooling passage of the head. Which really should not be an issue. If you could get it all to go in one direction it would be the best option but I don't think that is the case due to how the head is cooled.

Once you THINK you have it all, I would turn off the water and blow some air into the ports to really give any shavings a chance to get out of the engine. Then flush it again for a minute or so in case the air did dislodge some shavings. Then turn of the water to let it drain for a bit. Turn the engine back over and spray a ton of lube into the cylinders just to dissipate any water that may have gotten into the cylinders. I'd turn the engine over by hand to coat the cylinders with the lube and then spray a bit more in to be safe.

After that, I'd put it back together and feel pretty comfortable about running the motor and having a good season....

 

[howie099]

If the remman company tells you to do it his way and the engine fails I would just follow what he says. He is the company that has to uphold the warranty if he won't let you remove the head.

 

[rjcress]

If the remman company tells you to do it his way and the engine fails I would just follow what he says. He is the company that has to uphold the warranty if he won't let you remove the head.

Yeah. That is what I'm thinking.

 

[Robj]

I would still try a different type of easy out before you start drilling. Whatever you do, do not run water through the engine when it is not running.

 

[racerxxx]

Take the hose off the head cover. Measure the ID of the hole, go to Home Depot and get the largest tube that will fit inside the port. Duct Tape the other end of the tube inside a shop vac tube, seal it shut. Insert the other end inside the head cover close to where you will be tapping. Turn on said shop vac and just let it suck while you tap the threads. The water is also on it's way out of the hull, it'll flush right out.

As for NPT threads, IIRC they only seal on two threads of interference. The old rule, snug as a bug, you don't crank them like a bolt since they are tapered threads, not straight threads.

You can see the point of entry in the pic

This head cover is off in the correct orientation. You can see where the sensor is and how nothing will drop any where.

This would work too. But it's a little late now. (I think it the correct size)

1/8-27 NPT Spiral tap, it's designed to run the chips out of a hole rather then force them in the hole. They are great for blind holes.

 

[kicker]

Racer, you never stop amazing me with the stuff you think up, its so simple its stupid.

You could even leave that hose off and start it up on the hose for a few seconds to flush out anything that was missed. Or put a piece of hose on there so the water goes outside the hull.

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