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Engine runaway-crank seals?

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Blowncat 509

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Just rebuilt carbs, new fuel lines, new Oem selector valve, fired up and was dumping raw oil and smoking like crazy. I had put ball valve in rotary valve oil line after cleaning out all oil out of cylinders, cleaning oil tank, and switching to AMSOIL interceptor oil. Thought it was cleared out, but on the third time firing it up, it started to run away- so I jerked plug wires and pulled choke to kill it. Does this sound like I'm screwed, and need to pull the crank?
 
95 gtx 657x

Here's the oil that was coming from exhaust- I'm not happy.
 

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You are sucking air somewhere causing the lean condition.(runaway)
Since you had the carbs off I would get a mirror and look at the carb base gasket. More than likely one of them slipped while installing the carb.
The oil will burn off. It will look like a bug fogger for a couple minutes then clear out.
 
Runaway is an indication the air/fuel mixture is too lean (for whatever reason). Could be a carb base gasket is leaking, the fuel tank is near empty, the carb mixture screws are set incorrectly, an air leak at the crank seals, and maybe some other reason I've overlooked such as a leak in the fuel lines allowing air to enter.

I agree with jhjesse though, perhaps most likely is one of the carb base gaskets slipped out of place as you were bolting the carbs back on?
 
I glued gaskets to manifold, just so that wouldn't happen, also when I got ski it was hydro locked with injection oil from sitting for 2 years. Cleaned all that out, pulled exhaust , cleaned all that, replaced oil lines filter, switched to AMSOIL interceptor oil with a ball valve in the rv feed line. You might be right about the tank being low, but all the oil in the exhaust again is frustrating! If crank seals are bad, the valve ain't gonna
Help much, is it?
 
Runaway is an indication the air/fuel mixture is too lean (for whatever reason). Could be a carb base gasket is leaking, the fuel tank is near empty, the carb mixture screws are set incorrectly, an air leak at the crank seals, and maybe some other reason I've overlooked such as a leak in the fuel lines allowing air to enter.

I agree with jhjesse though, perhaps most likely is one of the carb base gaskets slipped out of place as you were bolting the carbs back on?

All lines are new, carbs rebuilt w/genuine Mikuni parts from OSD, pop off and high and low screws are at
Oem specs.....
 
All that sounds good. Hmm, was hoping you'd find a dislocated gasket.

Given the inner crank seals are toast it does raise questions about the outer crank seals as well.

The crankcase pressure leak check involves blocking off the exhaust and intake ports with gasketed plates, and airing up the case to 5psi soapy water on outside looking 4 bubbles. Some make these with plywood and a piece of rubber.

If the inner crank seals are toast though, might just toss a new crank in there anyway. How about RV surfaces, see if decent or scored and need work too?

My neighbor just bought a new yami ski last week, paid $15k. Ouchie!
 
Thing is, I was hoping for a decent runner for the wife & kids . The little XP ain't gonna cut it for everyone!
The gtx would have been good for that. Already have a 717 that needs a rebuild, now a 657x that also needs
To be gone thru. For the money involved, I could stick to my element, and finish up the whipplecharged 509
For my 25' SXT cat, and haul everyone around! @ 115+mph!
 
I suspect that you didn't get all the oil got out. It is tough to do after 2 years sitting. It was probably all the way through the exhaust. After you run it a couple times it should clear out. The ball valve should do the trick.

Air leak:
Do yourself a favor and pull the carbs and just have a look.
Did you have the RV cover off? RV seal?
Did you take the intake manifold off? Intake manifold gasket/seal
Just some possibilities
 
Don't get caught with those red fuel lines. They are not USCG approved, and it's a big fine.


Personally... I wouldn't worry too much about a run away, until you put it in the water. (you really can't tell anything on the trailer) It won't happen with a load, and it may never happen again.
 
Hey bro, these guys know more than me, but few know about filling a ski up to the spark plugs three times in 2 months more than me..
And what it LOOKS like to me is that regardless of whether you think you got ALL of that out or not, it looks like you did not.. To be honest, you're lucky/it's better that it was oil and not water that flooded the engine..
It's worth a shot, considering all the work you've done.. Have you run it on the hose and blipped the throttle for a bit to see if you can clear it all out? Most ppl recommend like a minute or less on the hose, mainly because of the driveshaft/carbon seal heating up bad..
So unless someone advises against this, what I would do is fire it up, THEN turn on the hose, blip the throttle a few times, then take like a 20 oz coke bottle, fill it with water, poke a hole in the cap, and squirt the pto/ driveshaft for a good 5-10 seconds, then blip the throttle again, then go wet the shaft again for 5-10 seconds, then blip the throttle again, and hopefully by now you're only spitting out specs of oil, if any.. Shouldn't take more than 2-3 min..


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And like doc said, even after that, I'd probably go run it in the water and see where you're at.. The only reason why I'd say do that stuff on the trailer first, is bc that's a LOT of oil to be sheening the ramp water with.. And people will rip your head off if they see it..


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Yep, just have a look and see maybe you missed a gasket but agree with everyone until you've splashed it or at least backed it into the water on a ramp than you won't know.

Splashed my Eliminator last weekend, first time in water in over 10 years and ran like a champ.
 
Use a spray such as WD-40 around the carb gaskets. And the carbs in general,,, If you get a sudden RPM change, you have found part if not all of the issue...
 
I haven't taken it to the water yet, cuz I don' t want to pay for registration and back fee's until I know it's worth it! But I do have the pump off, and I had the hose running to the line that would come from the pump , not the back flush line. So I figured I could run it for a longer period. Gonna add more fuel and try it again I guess....
 
I haven't taken it to the water yet, cuz I don' t want to pay for registration and back fee's until I know it's worth it! But I do have the pump off, and I had the hose running to the line that would come from the pump , not the back flush line. So I figured I could run it for a longer period. Gonna add more fuel and try it again I guess....



Regardless..... without a load on the engine... you don't know how it's running. A half dead engine will start, and rev on the trailer... but will fall on it's face with a load.
 
It had 150psi per hole when I checked it, but was wet from all the oil in crankcase, ( checked right after I pumped all the oil out)
Ski was given to me by my boss because it didn't run,(no spark)and he bought 2 07 gti 130's- now he has 3 gti's and a gtx wake.,
 
Can't you at least back it into the water strapped to the trailer and run it that way without registration?

Need a load so you can open up the throttle to really see how badly it runs and clear it out. The load will keep it from running away. But if it's too lean due to a big air leak there's a chance it will roast a piston riding around like that.

Lean hesitation and lean surging are the indicators, doesn't hurt really at low speeds to be lean aside from it will fall on it's face putting around but under a real load riding half or more throttle there's a lot of heat and mixture can't be too lean else detonation occurs and pistons roast.
 
Yea registration or not, if your trailer is plated and registered, keep it ON the trailer and do it when the ramp isn't as busy. I highly doubt anyone will bust your balls.. They like honesty. If you tell them you have a ton of wrench time in it and you just wanna see if it's seaworthy, they usually understand


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