Mark44
Katie's Boss
- Location
- 100% one place
I have used pro x on my last two motors with great luck.
Mark44
Mark44
UPDATED W. PICTURES- Is it just the gasket or did i stick a piston??
- Thread starter Woody
- Start date
Mark44
Katie's Boss
- Location
- 100% one place
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
yes, your rings are toast.
WAB
salty nuts
- Location
- coastal GA
You need to find out why it burned up the head gasket & overheated that cyl. I would also check the squish once you put it back together. You may have been pushing too much compression and not not realized it. IDK, but I'd bet it's not safe to run 190psi in a heavy couch. Were you running 93oct gas?
Is that one the metal multi-layer cometic head gaskets?
do you have a water line going in the back of the head and one coming off the front going to a pisser?
Maybe when the head was milled they did not mill it perfectly flat so the head gasket did not seal completly.
I have never heard of smoke from around the plug threads. I'd pick up another stock 760 head to run on it once it's fixed.
Is that one the metal multi-layer cometic head gaskets?
do you have a water line going in the back of the head and one coming off the front going to a pisser?
Maybe when the head was milled they did not mill it perfectly flat so the head gasket did not seal completly.
I have never heard of smoke from around the plug threads. I'd pick up another stock 760 head to run on it once it's fixed.
- Location
- Plymouth, MA
Woody
Need to save my money!!
- Location
- Long Island
Hey WAB...
Just purchased the ski...it had 7 gallons of premixed gas in it w. stabilizer from last season. I topped it off with 35:1 93 Octane fuel that I had for my Superjet (fresh gas).
As for compression- When I checked the compression at the guys house it was about 165 in both cylinders. I'm assuming the minute I put it under the load of the water it went kaboom. Unfortunately for me, I didn't bring it for a test run...I just started it in front of his house (I bought it from a guy who lived a few blocks from me, and he said at the end of last season it ran "perfectly" and he had a local jetski shop winterize it).
As for the gasket- yes...one of the multi-layer metal w. metal in the middle gaskets. Can i replace this with an OEM one? Or because the head is milled it has to be that metal one?
Waterline- Yes...One into the back of the head, one out of the front.
It also had the pro-tec pipe on it...which is why we think it burned up. My builder said that the carbs on the B2 are real hard to tune...so I'm thinking maybe that it blew up when it was at the conversion point between the high and low speed jets.
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- Location
- Houston/Galveston
yes. Your on Long Island. Look up Carl at Long Island racing. He can help you in person.
Woody
Need to save my money!!
- Location
- Long Island
will this gasket kit work (i can always use the other gaskets for later on):
http://www.sbtontheweb.com/Merchant...ode=41-403&Category_Code=41-4&Product_Count=5
or should i get the stock ones:
64X-11181-00-00 Head
6M6-11351-A2-00 Base
http://www.sbtontheweb.com/Merchant...ode=41-403&Category_Code=41-4&Product_Count=5
or should i get the stock ones:
64X-11181-00-00 Head
6M6-11351-A2-00 Base
Woody
Need to save my money!!
- Location
- Long Island
i think you're talking about Island Racing in Port Washington?
If so, I've worked with Carl before, he's got great prices and he's a good guy.
I disagree with this completely. An overbore, new pistons, rings, and a gasket kit is not exactly chump change. So far I haven't seen anything saying that the pistons were toast from Woody. Only speculations that because the gasket blew and the engine oveheated, the pistons and cylinders are now toast.
The blown gasket caused the overheated cylinder. I've blown a lot of head gaskets on my 750. Most had to do with head and cylinder not being perfectly flat. The extra problem came from the couple times I hydrolocked the engine. Every time I blow a head gasket, the engine overheats. One time the engine overheated so bad that it actually sputtered out and died. Water instantly boiled on the head for the first 15-20 seconds. In the end, I just flattened the mating surfaces, installed another head gasket, slapped it all back together, and haven't had a problem with it since. Still works like a champ and holds excellent compression.
I agree that new pistons, rings, etc. is most definitely the best option for longevity. However, budget, time, and ability are playing a significant role in the decisions being made here.
Woody
Need to save my money!!
- Location
- Long Island
SUPERTUNE
Race Gas Rules
- Location
- Clearwater Fl.
Use OEM Yamaha headgasket for a 760 cc.
IMO, I would pull off the cylinder and see how much damage you have.
The piston did have a light seizure from what I can see on the cylinder wall.
Usually you can save it if the seizure didn't collapse the piston skirt, measure the good piston with a micrometer for size, now measure the seized piston and see if your under .001 difference, if more than .002 smaller you'll need to replace the bad piston.
Have a machine shop hone the cylinder lightly (acid wash the seizure spot on the cylinder wall with muratic acid first to remove any smeared on aluminum from the piston) and see how much piston to wall clearance you have.
About .0055-006 is about max with a cast piston. If you decide your piston clearance is good on the seized piston, have the piston glass beaded to remove the seizure spots.
Make sure the rings are free in the ring grooves and put it back together again.
IMO, I would pull off the cylinder and see how much damage you have.
The piston did have a light seizure from what I can see on the cylinder wall.
Usually you can save it if the seizure didn't collapse the piston skirt, measure the good piston with a micrometer for size, now measure the seized piston and see if your under .001 difference, if more than .002 smaller you'll need to replace the bad piston.
Have a machine shop hone the cylinder lightly (acid wash the seizure spot on the cylinder wall with muratic acid first to remove any smeared on aluminum from the piston) and see how much piston to wall clearance you have.
About .0055-006 is about max with a cast piston. If you decide your piston clearance is good on the seized piston, have the piston glass beaded to remove the seizure spots.
Make sure the rings are free in the ring grooves and put it back together again.
- Location
- baldwin ny
the cylinder is at .5 now who said anything about boring it? i guess your time is worth nothing to keep pulling the moto apart when it pops again cause you were to cheap to fix it right the 1st time. i like to get around 300 hours of my motor.
Yes I apologize...you are God and I am worthless.:notworthy:
My money is worth more than my time... I can pull, rebuild, and reinstall my engines in a few shorts hours but I seriously doubt that Woody (no offense) has the experience to do that. Hence the recommendation to just slap a head gasket on and see what happens. If the compression sucks, he's only wasted a few minutes. You're talking about buying a brand new top end because of a blown head gasket. This is the perfect time to slap everything back together and ride out the season...if possible. When it's too cold to do anything, then rebuild it properly.
You can do what you want with your money and time but both of my ski's run great. My word isn't law, I'm just trying to offer up an alternative since Woody seems very hesitant about rebuilding the motor.
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If that picture is showing aluminum from the piston galled to the cylinder then you should buy a top end kit and get the cylinders bored/honed and address the overheating issue (keep reading). If that is just slight scoring and the flash from the camera made it look worse than it is, then I would check the head and the top of the cylinders for clearance with a know flat edge and feeler gauges for less than .002" since you have it off (Yami motors are real picky about this for proper sealing). If you actually saw exhaust coming from the spark plug threads, then maybe the plug vibrated loose causing a severly lean condition, blowing the head gasket. If that is all good then make sure all cooling lines are clear by blowing air through them. This was caused by overheating so that issue needs to be addressed, but I also don't see any cross-hatching in the cylinders either, but my monitor is not the best. You need this for oil retention in the cylinders. If there is no galling, there is cross-hatching in the cylinders and you find the reason for the overheat issue, I would just put a new head gasket on it. I have put new head gaskets on skis with significant scoring in the cylinder walls and maintained 145 psi (stock heads) for seasons (yes, plural). Good luck.
- Location
- baldwin ny
just buy a $60.00 head gasket for fun. or just listen to redneck motor guy run it tell it blows and wrecks the cylinder. penny wise dollar foolish.
Woody
Need to save my money!!
- Location
- Long Island
easyyy boys. thanks all for your input. ive made a decision....gonna just put in some new pistons and bore out the cylinders....prox comes w. everything for like $85 i think (carl from island racing is a good guy). i'd rather spend $300 now vs. $7-800 later. my main ski is a SJ so its not like i'm out of commish for the season. this is just a ski for my friends and fam to use...and for me occasionally to bring out into the ocean for some BRAPPPPPPPinnn lol.
thanks everybody again...couldn't have done it without ya
thanks everybody again...couldn't have done it without ya