09-25-2009, 01:54 PM #1
2000 XL1200 LTD Blown 3rd Cylinder
Recently had it out on the lake and during a run at full speed, it bogged down and I could only get about 25 mph out of it. Took it out of the water, found some rocks in the intake grate, inspected the impeller which looked undamaged, checked to make sure no fishing line or anything else had wrapped itself around the driveshaft, all the plugs were firing, and still couldn't get it run right.
Pressure test confirmed no pressure in cylinder #3. Here's why:
And the head:
1. Obviously this cylinder ran hot, but why? Oil lines seem to be in place. I'm the second owner, so unsure about any carb maintenance prior to my ownership. Waverunner has about 50-60 hours on it, bought it with around 30-40.
2. What's my next step? I think that I need to check out the crank to see if any metal remnants made their way down there. I guess that I also need to pull the cylinder off to check out the rest of the piston and cylinder.
09-25-2009, 03:52 PM #2
I doubt the previous owner rebuilt the carbs with such low hours but it is 9yrs old so thats where i'd start.Everybody is different when it comes to rebuilds and i'm sure there are a few on here that have just replaced cylinders and pistons without stripping the entire casings.I myself have done it many times and but only split the cases twice.It depends on how much pride you take in your work and are you willing to risk doing the job twice.There is tons of info on carbs and premixing on here.
09-25-2009, 04:17 PM #3
Seems that is a common recommendation - to go pre-mix. I think that I will go ahead and do that. If this problem was a result of oil starvation, at least that's one thing that I shouldn't have to worry about moving forward.
You mention that you've done this a few times - how many hours should I expect to get out of this engine? I have a hard time believing that your engine is likely to have catastrophic failure with more than 100 hours (or less in my case), but the more I read, the more it sounds like that's the case.
09-25-2009, 04:21 PM #4
- Join Date
- Aug 2007
- Bridgeton nj
what oil are you using in injection pump?
drain your gas filter and tank and look for water, because it usually ends up in #3 carb.
it looks like you ran it pretty long with a blown piston and make shore you check the crank
09-25-2009, 04:40 PM #5
So, not sure how long it "too long" in a blown cylinder.
09-25-2009, 04:45 PM #6
It might not have been oil starvation,it may have run lean with dirty carbs but get rid of the oil pump anyway,the majority on here are running premix.When you say catastophic i take it you mean blowing a hole in the cases?i dont think it happens that often but it depends on how well you rebuild it,if you just slap it together and hope for the best then expect the worst.
I did about 9 or 10 pistons and about 3 cylinders,(in a year)it was all because of the carbs,since i have had the help on here by some fantastic guys,i have got it running better than ever and beating alot of ski's on the water.
If you are prepared to do it right,get a full gasket set and a matched piston and cylinder ordered.Get the engine back together,torqued up and pressure tested,then start on the carbs and jetting specs.
Build them both right and you'll have a recipe for hapiness and a good starting point for future mods.
09-27-2009, 05:35 PM #7
Pulled off the cylinder - this is what I found
I was able to get into the cylinder this weekend and see the damage to the piston. There is some slight damage to the cylinder wall, not sure if that happened first and caused the piston to catch on it, damaging the rest of the piston.
There is also a little bit of water in the bottom of the crankcase - I would guess maybe a tablespoon's worth or so. Could this have caused this type of damage?
I read on another board that towing could introduce water into the engine & crankcase - I had to tow another 1200 not too long before this happened.
Cylinder looking at it from the left/port side.
Looking down into the crankcase
Looking at the piston from the right/starboard side
Cylinder sleeve - there's a small hole that lines up some head damage on the piston
You can see the damage on the piston head that lines up with the damage within the cylinder wall. What came first - the piston damage or the cylinder wall damage? (Chicken or egg?)
So, what's next? I couldn't find any LARGE metal fragments, so I'm assuming that whatever broke off the cylinder was pulverized by the crank and motion of the crank, piston, etc., or blown out the exhaust. Looks like I need to pull the engine and at least clean up the crank.
How do I determine whether or not I can re-use the crank?
09-27-2009, 08:16 PM #8
You might be able to reuse the crank, I did that couple times. Make sure that you clean and wash the crank case very well. I washed it with gasoline. Pour it in the case, spin the engine by hand, take it out with a small pump, strain it than do it again. That should work.
09-28-2009, 07:55 AM #9
Gonna have to split that one and clean it good. Looks like the piston ring hit the cylinder. And #2 is a bit black, that could be lean. Dont try and clean the crank while its inside the case you will regret it.
09-28-2009, 09:39 AM #10
Thanks, I was definitely sure that I shouldn't clean out the crank without splitting the case.
Any recommendations on parts? I was thinking SBT before I started reading these forums in depth. Now, I'm not certain.
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