Thoughts on Cylinder Head condition

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Tiggo

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The cylinder head cover on my 2004 GTI LE RFI had some bubbling on it.20220219_190339.jpg So I purchased a replacement.20220219_190329.jpg I also purchased the o-ring/gasket set for the 787 engine from OSD. After removing the cover I saw this...20220219_140101.jpg20220219_140119.jpg20220219_140211.jpg20220219_142854.jpg20220219_143008.jpg Looks like it has never been removed. The ski has 80 hours on it.

I was able to clean it up a bit with a wire brush and penetrating oil. 20220219_153629.jpg

20220219_153650.jpg20220219_153658.jpg
I was also able to clean the bolts up to look like new. I also chased the threads and cleaned everything. I'm prepared to put it all back together but wanted some perspective on the shape of the cylinder area. There is a nice crossed hatch honing on the cylinder walls but the bits of rust on the outside of the walls is what concerns me the most. Is that normal wear for a 18 year old 2 stroke? It had 150 psi compression on both cylinders before I took it apart. I'm replacing all the o-rings and going to put it back together IAW the shop manual. Any suggestions? Does it look okay? Thanks in Advance.
 
You don't have a picture of the head combustion chamber. How does that look? And pitting?

As for the appearance and condition it looks OK to me... par for the course in condition. Just make sure everything is clean when you go back like you are doing. Good Luck !
 
The combustion chambers look like new. No pitting and completely smooth. There was a little carbon but it cleaned right off. Thanks for the quick reply. The before pictures were a little scary. It looked like water was getting past the o-rings. I've rebuilt car and motorcycle engines and never saw that kind of corrosion so it was somewhat startling. I'm going to use blue loctite on the bolts and molykote 111 under the bolt heads. Also Loctite 518 in the o-ring groove of the cylinder sleeves. Should I also use 518 on the o-ring groove of the cylinder head cover? Also, the replacement cyclinder head cover o-ring is round versus the square one I removed. I'm guessing OSD substitutes it on purpose based on availability. Sound okay?
 
Personally I don't use loctite. I use Marine Grease mostly and I coat the whole head bolt. If you've ever had trouble getting stuck bolts out of these engines you know why. I use the marine grease on all the o-rings as well unless there is a lot of pitting or some damage to the groove. For the smaller red o-rings that seal the spark plug area of the head cover I put 518 there.... sometimes. Mostly I just use the grease. Use what they call for and you'll be fine I'm not telling you what to do. It will be extra work if you have to back track. 518 cures really quick. :)

I started putting 518 loctite under the head bolts to try to seal them better and hoping that will keep any moisture out so the bolt holes won't corrode.

If we are talking about the same thing, the cylinder head cover o-ring gasket should be round. The two square gaskets go on top of the cylinders and seal the water jacket. Pain in the butt to get that clean but you gotta get all that junk out of there. I'm gonna buy a vapor blaster. I spend egregious amounts of time cleaning and prepping parts but I like pretty. :D Good Luck !!
 
Thanks Gene. I agree about the loctite on the bolts. I will use marine grease instead. I'll just recheck the torque on the bolts once in a while. Thanks for the help and suggestions. If you think of anything else...fire away. I'll probably finish putting it all back together tomorrow afternoon.
Alan
 
It's a good idea to keep an eye on the 10mm bolts on the exhaust brackets (the bolt that screws into the pipe) I've seen a few skis with those bolts completely missing. Check your exhaust pipe for leaks and corrosion at the welds. Remember those are just things that I do, others might not agree. :D
 
Just a follow-up. Prior to dismantling I got 150 psi on both cylinders. After cleaning and replacing cylinder cover, o-rings compression increased to over 160 psi. Hopefully that is a good sign.
 
Hi Iam doing same and where is a good place to buy crank assy and gasket kit. Mine leaks oil through crank seals
 
Hi Iam doing same and where is a good place to buy crank assy and gasket kit. Mine leaks oil through crank seals

Many of us have installed a valve on the oil pump feed line to prevent the oil from leaking into the engine when it isn't running. As long as the leak isn't too bad this "fix" works really well. If you are rebuilding the engine I'd get a rebuilt crankshaft because the prices on the new cranks have skyrocketed and delivery can be a long way off. If you get yours rebuilt you'll save $$ and get it back much sooner. Good Luck !
 
Wow. I just made an identical post with this same condition, except mine has been bored 50 over. 1 cylinder looks identical to yours. I have no cross hatching tho so may still need to hone. Did you put 518 on the square gaskets? I saw in the manual about filling in the O ring grove with 518. Wasn't sure if the square gaskets need it or not. Strange how this pitting is evidently acceptable. Anybody know what causes it?
 
Wow. I just made an identical post with this same condition, except mine has been bored 50 over. 1 cylinder looks identical to yours. I have no cross hatching tho so may still need to hone. Did you put 518 on the square gaskets? I saw in the manual about filling in the O ring grove with 518. Wasn't sure if the square gaskets need it or not. Strange how this pitting is evidently acceptable. Anybody know what causes it?
I used it where ever the manual said too. It can't hurt. It stays soft so only use a little.
 
I put waterproof grease on the o-rings unless the surface is irregular and pitted. They come apart nicely. :)
 
I put waterproof grease on the o-rings unless the surface is irregular and pitted. They come apart nicely. :)
Thanks for that. I was just looking up whether I can use Superlube White Lithium grease as a Marine grease. The white lithium seems to be toward the bottom of the list, but I prefer it as it is what I use on everything else, including dielectric grease needs, so much easier for me to use that.
 
Many of us have installed a valve on the oil pump feed line to prevent the oil from leaking into the engine when it isn't running. As long as the leak isn't too bad this "fix" works really well. If you are rebuilding the engine I'd get a rebuilt crankshaft because the prices on the new cranks have skyrocketed and delivery can be a long way off. If you get yours rebuilt you'll save $$ and get it back much sooner. Good Luck !
Yes on the ball valve! Its a great fix and be surprised if you spend much over $10 and no engine removal/reassembly. If you go the crank replacement route, you will learn very quickly that the term BOAT is an acronym (bring out another 1K).
 
I have read of some installing a selonoid valve in the oil line. That is the route I'm going. I'm wondering if anyone that has one installed can share the valve they are using. I am planing to insatal a switch on the driver control panel so I don't have to open the engine compartment and remove the storage tray every time I want to take the boat out. Anyone has any ideas I am open to what works best.
 
I have read of some installing a selonoid valve in the oil line. That is the route I'm going. I'm wondering if anyone that has one installed can share the valve they are using. I am planing to insatal a switch on the driver control panel so I don't have to open the engine compartment and remove the storage tray every time I want to take the boat out. Anyone has any ideas I am open to what works best.

If you are going through the trouble of installing a solenoid valve, which I have considered as well, install it so that the valve opens automatically when th engine is running. The only problem I see with a solenoid is that you won't be able to verify it is opening. Hence... no oil. It is easy enough to pop off the seat and open and close the manual valve. I can leave the valve on my wife's ski open a a week when the ski isn't running. If you're riding the ski every day even for 10 minutes the valve can stay open.
 
I'd like verify the amount of oil in the crank case that causes problems (my guess is about 3 ounces). I even thought about measuring the amount of leakage on my wife's ski to to get an idea. I know that after 10 days of the valve being open and the ski not operating, the engine will spin a few seconds and lock up. I'll then have to remove the spark plugs, make a mess and spend about 20 minutes purging and wiping. I've actually considered making a fitting to screw into the spark plug hole with a hose attachment so I can drain it to a bucket. Oil isn't always a bad thing... keeps the corrosion down. LOL
 
Not sure the leakage is due to the amount of oil in the crank, but instead, the level of oil in the line feeding the crank (head pressure). I put in a ball valve and new clear oil line in an "s" shape. Typically, I open the ball valve a couple seconds before starting out for the day. I've never seen the level in the line ever approach the bottom of the engines and therefore always have full oil in the cranks. In fact, it appears that placing the ball valve near the top of the cylinders reduces the head pressure enough to almost completely stop leakage past the seals. Could probably go most of a season without recharging the oil line.
 
If you are going through the trouble of installing a solenoid valve, which I have considered as well, install it so that the valve opens automatically when th engine is running. The only problem I see with a solenoid is that you won't be able to verify it is opening. Hence... no oil. It is easy enough to pop off the seat and open and close the manual valve. I can leave the valve on my wife's ski open a a week when the ski isn't running. If you're riding the ski every day even for 10 minutes the valve can stay open.
Mine is a seadoo jetboat so gotta open the engine hatch and take out the rather large storage tray that is full of life jackets, etc., so a selonoid will be much easier.
Yeah, I'll have to trace out the wiring because the MPEM isn't like a regular switch. Would have to take the 12v off of a circuit that has constant voltage when running. Not sure what circuit that may be the way these are wired. Otherwise a toggle switch will need to be installed. I've seen chat on here about it but my searches are yielding nothing on the topic. I'll figure it out, was just hoping to find someone that already knows what works best on the setup.
 
Hi, I'm having issues with water getting sucked in past the runner oring (the one in the groove around the cylinder) is there a type of gasket maker I should put there? I used a gasket maker but it failed after 2 rides.
Also have some damage to the groove, any ideas on how to fix that? Jb weld?
Water keeps getting in and leaving me stranded. : (
Thanks : )
We will answer your questions in your thread.
 
I used it where ever the manual said too. It can't hurt. It stays soft so only use a little.
518 doesn't stay soft. It is anerobic. Once you tighten the bolts and the air gets removed it begins to harden and does so very quickly. It is bad azz if you have an irregular surface you are trying to seal. Problem is cleaning it off afterwards. LOL in 15 minutes if you remove it you'll be scraping the material out of the grooves and trying to get it off the o-rings. Good Stuff though but I don't use it unless there is an issue.
 
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