05-10-2013, 06:42 AM #1
I got a 01' 1200xlt with power valve with a bad 3rd cylinder 0psi
My Dad gave me his 01' Yahmaha 1200 XLT waverunner. It was given to him because it has a bad 3rd cylinder.
Yesterday I checked the compression. Removed all plugs and connected my gauge. Number 1 cyl was exactly at 100psi. Number 2 was appoximately 105 psi, number 3 is 0. I poured some oil in the cylinder and it's still 0 psi.
My dad had found that the 3rd cylinder oil line has come off the carburator. It seems to be a common issue with these. Stupid zip ties.
I know it needs a new top end now and a new cylinder and piston for the #3, but I think I should put new piston and rings in 1 &2 as well since the psi is near 100. It's about time for a rebuild.
Ski has 190 hrs on it. Everything else on the ski is in good shape. I am hoping that the crank is fine but I will see as I pull it apart. I know 2 strokes are pretty resilient. I will post pics up as I go along. I am a picture whore. I take pics to remember the way it comes apart so I always have pics of the stuff I rebuild.
NOTE: I am very mechanically inclined. Not ASE certified or anything but can fix just about anything and do it right, not rigged.
So I am in the market for AT least a top end kit with a 3rd cylinder. I am debating blocking off the oil pump and running straight pre-mix to prevent this issue again.
Another plus is my Father In-Law used to be a Yahmaha mechanic for Doraville Yahmaha so he can spot me as I rebuild it.
Any advice you want to give is more than welcome.
05-10-2013, 07:18 AM #2
Can I bore these cylinders out or do I have to replate or buy new?
Also, what are water eaters and what do they do?
05-10-2013, 08:20 AM #3
- Join Date
- Feb 2013
- Panama City Beach, FL
You can bore them out but you have to get them re coated with nikasil. You can also sleeve it but I don't think you will find many that would recommend that. The water eaters I think you are referring to are waveater clips and couplers. The clips keep the pins from coming out of the exhaust valves and the couplers go on the shafts in between each valve. They fix the slack in the system causing the valves to not open in sync.
05-10-2013, 08:38 AM #4
Get the wave eater clips it prevents the power valve from dropping and nail your cylinder causing obviously an issue...simple install and get the coupler as well so the power valve opens fully the old ones were plastic and you start to get a lot of play and it does not fully open...while your in there make sure the PV are clean and use a good oil that helps keep it clean...when I had my 03 I was using Klotz skicraft one of the best oils for oil injection and PVs...when I destroyed my middle cylinder I had it replated thats the way to go...I never went premix if you stay injection just get new oil lines and secure them properly there is a ton of info on this site for this ski and work you need to do just search and you will get a lot of reading material.
05-10-2013, 10:08 AM #5
I would definitely go pre-mix. Especially if you are rebuilding that engine. The failure of a $50 oil pump WILL cause the loss of a $4K engine. It will also guarantee and allow you to experiment with the mix ratio. That's a no-brainer. Some other easy performance mods you can do is eliminate the catalytic converter and install the D-plate with e-chip. Rebuild your carbs, install new reeds and stuffers, open up the intake by removing the stock air box and get some RIVA FA's. That's a good start.
05-10-2013, 05:06 PM #6
step one is get the service manual then pull the cylinder head to see what your up against.
-this can be done w/out removing the exhaust stinger but since you know one cylinder is bad go ahead and snatch off the stinger pipe (big-ass pipe that is in the way and attaches to two cylinders).
Hopefully you will only need a used cylinder/piston and head, also new rings. The piston lets go easy to save damage to the crank but they do take the head out with them.
-recently got through this on a 1300 for about $800.
I would also look for some used reeds from a 1300 (big upgrade in durability & performance over the 1200 reeds)
Oh, and remove the cat conv if still installed.
Depending on budget, I have the ultimate fix !!
-buy a smashed up 2008+ RXPx, motor mounts & drive shaft and put that engine in you XLT
05-11-2013, 09:46 AM #7
When you pull the cylinder and piston post some pics of the crank and rod. if the rod shows signs of heat you will want to pull the engine for a total rebuild and new crank or send the crank off to have it rebuilt. also wave eater clips are a must but DO NOT use the wave eater couplers between the cylinders that connects the power valve shafts. the wave eater couplers have a metal pin that locks in the slot in the power valve shaft and the metal pin to metal shaft causes excessive wear on the shaft and you have more slack than you ever had with the plastic ones. the best thing to do is use some plires and close the slots a little so the plastic couplers are hard to get back in. i do it on all stock boat i work on but on my triples i use something different. good luck with the project and post some pics.
05-15-2013, 06:49 AM #8
Ok, I love all the replies. Gonna look for those 1300 reeds. I am planning on getting a D-plate and chip as well as the Wave eaters. The couplers between cylinder 2 and 3 was broken, don't know if that had anythig to do with the failure or deterioration of the cylinder. But I know the oil line was off when my Dad originally got the ski.
Ok onto the good stuff. I took it apart on Monday. WOOOOO! That was fun. Check it out!
I pulled the head and saw this
This is what happened to the head, not good but doesn't look destroyed.
Pulled the jug off
Found this in the front of the Cat
I tried to get the wrist pin out by tapping it but quickly realized it was NOT moving. (Yes I pulled the retainer clip)
Although I didn't care to know, I now know how many 7/8" wrenches and one crescent wrench it takes to press out a wrist pin with a bolt, washer and nut.
The wrist pin bearing looks good although it was sticky when rocked back and forth
Here's my photoshoot with the piston
Here is the rod and crank view
The crank and rod looks pretty clean. There are metal flakes everywhere but I plan to vacuum out the crank and then rinsing with carb cleaner and blow it out with air and repeat and repeat.
I have compression of approximately 110psi with Wide OPen Throttle on #1 and #2 pistons but I am going to go ahead and bite the bullet and get the complete top end kit and replace the front two cylinders and pistons as well. Make this thing nice again. With 170 hrs on the engine I think a new top end would do it good.
What does everyone think so far?!?!?
Also, the side of the piston that is rounded off was the side where the power valve is. I think it was hitting the cylinder although the valve doesn't LOOK damaged.
Last edited by jwrape; 05-15-2013 at 07:35 AM.
05-15-2013, 07:39 AM #9
You are not going to find a better cylinder than the stock ones. i would not send 2 good cylinders to SBT for sleeved ones.....if you are set on new pistons then order them from Riva and new rings. you can send the cylinder to millennium technologies to have it renicked and it will be as good as the stock ones that came on the boat.
If you are seeing a lot of metal it would be a good idea to pull it out and clean the crank properly and clean and check the reeds. also go ahead and go through the carbs and clean them if the gaskets look good you can reuse them as well.
05-15-2013, 08:45 AM #10
I get SBT products at cost. I can get a full top end for just under $400. With that being said, can I re-use the front two cylinders the way they sit? They are in good shape. Just put new rings in and go? If So I will definately do that. But I do want my full compression back in the cylinders.
As for the 3rd damaged cylinder. Is it possible to repair it or re-nickel it? If so I will definatley re-use it. I would love to re-use all the cylinders if possible.
I know I will have to at least replace that one piston and rings set as well as all the wrist bearings, washers and clips.
I am not familiar with the durability of these cylinders but if I can re-use them, please let me know how. I don't want to replace the OEM if I don't need to. It made it 170 hrs without issue, I figure they are pretty durable.
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