02 STX-R No Compression on Cyl 2 - Options?

[bobbycdefg]

Worst case scenario -- I bought an 02 1200 STX-R on Wednesday. Rode it for 2 hrs on Thursday(ran great, got it up to 65mph). Saturday my daughter put 5 more hrs on it(Still 65 mph). Sunday it ran well for about 10 minutes, then the engine stalled, after that, max speed was about 40 mph. My daughter continued to ride it for 3 or 4 hrs at 40mph. I go it back home, did a compression test and cyl 1 and 3 had 150 and 160 lbs pressure, cyl 2 had 0! What are my options?
1) New SBT Premium engine? (SBT - $1799)
2) New SBT Standard engine? (SBT - $1499)
3) New SBT top end (SBT - $699)
4) Rebuild top end myself??
5) Other options?

What damage can be done by continuing to run on 2 cylinders (max 40 mph) and then rebuilding top end later?

[WATERCRAFTSERVICES]

Re: 02 STX-R No Compression on Cyl 2 - Options?

OMG DO NOT!!! contunue to run on 2 cylinders. If you have not yet contaminated the bottom end then you most likely will. Pull the top end apart now. Look at the cylinder and piston in question. Determine the failure and its possible cause. If you have only top end damage then go with an SBT top end kit. You will be better off than trying to do it yourself unless you have access to a good machinest with good prices.But most important determine what caused the initial failure or it will kill the new top end also.

[FastUltra]

Re: 02 STX-R No Compression on Cyl 2 - Options?

Can you post pictures with a nice digital camera? Pull the cylinder off and take some pictures of the wall and piston top. From that we can help tell you what caused the death. I would not take the change of riding it more. You can begin to tear the top end down before your service manual gets there. Basiclly you have to remove the pipe. Flame arresters, carbs, Exhaust manafold, head, water intake log, and then the base bolts. It should then slide off the piston. I would wait for the manual before reinstalling due specific intructions needed

[bobbycdefg]

Re: 02 STX-R No Compression on Cyl 2 - Options?

That's what I figured. It may be too late though. My daughter continued to ride it Sunday when she could only get 40 mph (She says she put about an hour and a half on it). I guess I'll have to start tearing it down and see if I can figure out what happened. Any suggestions would be highly appreciated. Looks like SBT has some pretty detailed engine removal / installation instructions. Can I remove the top end without removing the entire engine? I have ordered a service manual and I'm sure that I'll find that info there. How will I know if the bottom-end is damaged once I get the top-end off?Thanks

[FastUltra]

Re: 02 STX-R No Compression on Cyl 2 - Options?

You can remove the top end with the engine in the boat, the service manual says no, but it can be done. If the engine is still turning over fine, I don't think any damage was done. If after you take the top end off, try turning the engine over by hand using the driveshaft. If you here any grinding sounds or it is hard to turn you will know you have a problem. Note: the engine will turn easy one way and harder the other, turn it the easy way.:)

[bobbycdefg]

Re: 02 STX-R No Compression on Cyl 2 - Options?

Thanks Paul, I'll use the SBT instructions to get it to that point and I'll take some pics along the way. I noticed a puddle of oil in the bottom of the hull and thought that maybe the oil hose on the #2 cylinder could have been leaking and not providing oil into the cylinder but my daughter confessed that her friend spilled some oil when he was filling the oil tank so I'm not sure. By the way, I forgot to mention that because the engine was having a hard time cold starting and the fact that the previous owner left some extra plugs under the seat, some well intentioned folks at the lake decided to change the plugs for my daughter. I don't know if this matters but there was a different type of plug in cylinder 1 than in cylinder 2 and 3. Cyl 1 has NGK B10EG and Cyl 2 & 3 had NGK BR10EG. The previous owner said he was using colder plugs than stock to try to get more cruising speed.

[FastUltra]

Re: 02 STX-R No Compression on Cyl 2 - Options?

Well neither of those plugs are correct, and if the heat ranges are way off, that could be your problem. If the piston has a hole or dent in the middle that s what killed number 2.

ONLY use NGK BR9ES

[Technical Support]

Re: 02 STX-R No Compression on Cyl 2 - Options?

there was a different type of plug in cylinder 1 than in cylinder 2 and 3. Cyl 1 has NGK B10EG and Cyl 2 & 3 had NGK BR10EG. The previous owner said he was using colder plugs than stock to try to get more cruising speed.

Then he had no clue whatsoever.

[bobbycdefg]

Re: 02 STX-R No Compression on Cyl 2 - Options?

I just noticed that the service manual on buykawasaki.com is for the JT1200C -

I think the JT1200C (according to the NGK site) is the engine on 2004-2005 1200 STX-R and the JT1200A is the engine on the 2002-2003. Do I need to try to find a service manual for the JT1200A or are the engines pretty much identical?

[FastUltra]

Re: 02 STX-R No Compression on Cyl 2 - Options?

no the JT1200A is the Ultra 150, there is no difference in any 1200 engines except the 99s and then the deck change in 02.

[bobbycdefg]

Re: 02 STX-R No Compression on Cyl 2 - Options?

OK, I took the engine apart last night and it was pretty obvious why I was getting no compression in #2 - the piston has a large piece broken off. I'm no expert but the #2 cylinder head looks very clean - as in no brown oily color, compared to the other 2. It looks like a piece of a piston ring broke off and blew a big hole in the side of the piston, then banged around inside the cylinder finally ending up lodged in the top of the piston. So where is the rest of the missing piece of piston? I'm guessing that either the hose delivering oil to the #2 cylinder is clogged or the oil pump is not pumping oil to the #2 cylinder (is that possible?) The #2 cylinder wall is gouged. Other than some carbon deposits on the front cylinder, the other 2 cylinders look ok to me - the cylinder walls feel smooth. The crank still turns very easily and I got 150 and 160 psi from cyl #1 and #3. Based on this info what should I do? I have attached pictures.
Is it possible/cost effective to only to replace the #2 cyl/head/piston/rings? Or should I replace all 3?

Thanks,

[Technical Support]

Re: 02 STX-R No Compression on Cyl 2 - Options?

You can't tell anything until you get the engine torn down and have the pistons out - we need pics of all the sides.

[bobbycdefg]

Re: 02 STX-R No Compression on Cyl 2 - Options?

I took more pictures than I posted. I was going to wait on my service manual before I went further but I guess I don't really need it for disassembly. I've been using the SBT engine removal instructions to this point but they don't go into engine disassembly. I guess I've still been trying to decide which route I'm going to take for repair. The cost to buy the parts, from the Kawi dealer, to repair just the 1 cycinder (cylinder, head, piston, rings, etc) is near $1000. For less than that I can get the "cylinder exchange" complete top-end from SBT ($669 + $46 shipping) which includes all 3 cylinders, pistons and everything else I need except the heads. Then I have to get one head to replace the dinged up #2 head (about $120). That will total me about $850 or so for a complete top-end. But before all of that, I guess I need to get down into the bottom-end and see if the crank is contaminated or not. I'm not sure I'll know by looking at it. I'll get some more pics up when I get there.

I have been posting lower resolution pics to try to keep the file size near 100k but I have higher resolution versions that I could zip and email if someone wants to see them. I also have a lot more pics than I posted. I've been taking pics of the entire job as I have been removing and disassembling the engine. Currently, the engine is still in the ski turned on it's side (it is heavy and I don't have a hoist). I'm gonna get a friend to come over and help me lift it out so I can set it on a bench and make it a little easier to work on.

I'm sorry if these posts are a little long but I am trying to convey my experience and thoughts to let others know what they are in for if and when they have this same problem. I have rebuilt a couple of automotive engines in the past but this is my first shot at working on a 2-stroke. So far, things have been fairly easy. I have had a few challenges with instructions to remove bolts I couldn't get to without removing things in a slightly different order than the instructions. (bottom 2 fire arrestor bolts, starter cable and water hose blocked by the cylinder assembly). I did break off one of the 4 PTO shroud bolts due to my own stupidity. (had my portable drill set the wrong way after I had reinstalled the engine ground bolt back into the engine) so instead of removing the first shroud bolt I tightened it until it broke off :o .
That's it for now....

[Technical Support]

Re: 02 STX-R No Compression on Cyl 2 - Options?

You don't need to limit your resolution here. We just need to see the piston sides.

[bobbycdefg]

Re: 02 STX-R No Compression on Cyl 2 - Options?

OK. I'll take the cylinder off tonight and put up some pics of the piston.


:emoticont