New Rings, Break-in?

[B_PWC]

I have read a lot about how to break-in a new motor or even new piston and rings....

Are the steps any different if the cylindars were only honed, same pistons, and new rings?

I am finishing up the install of new rings on my Seadoo XP 587. The existing sleeves and pistons are from SBT; I also purchased their rings (1.00mm).

Thanks

 

[B_PWC]

Now I am really confused. I got the new rings installed and they are the correct size but the compression is lower with the new rings; about 10 psi less.

Does the compression increase as they get broken-in or is that wishful thinking?

SBT piston, rings, sleeves.

 

[6KJR]

Some people run some oil with a couple tanks of fuel and take it easy with the new rings. No LONG wide open runs, and varying the throttle.

Others engine builders will not use oil as they say the more oil, the more heat and its harder on the rings...

As for compression, it may rise once they seat properly into the cylinder walls. Give it some hours before you get too worried about it.

 

[LouDoo]

Like he said, nothing is perfect, the rings need to seat before the compression will improve.

Lou

 

[B_PWC]

Thanks for the reply. I saw 120 psi on each, they were about 130, and was a really concerned.

 

[Dr Honda]

As rings break in, the compression will get better, and so will the heat trasport... but new sharp rings should still have good compression. (140 or better)

1) Did you check the end gap?
2) Did you check the cyl to make sure they are round?
3) did you hone the cyl walls?
4) did you install new head and base gaskets?


Other than adding 2oz/gal extra oil to the fuel... I'm not going to tell you how to break them in, since no one likes my method.

 

[B_PWC]

I should have clarified my first post. Before changing the rings I got ~120 and ~130; now I get ~120 on ~110.

1) Did you check the end gap? Yes, it was on the upper end of the tolerance; based on the manual.
2) Did you check the cyl to make sure they are round? No, don't have the proper tool
3) did you hone the cyl walls? Yes
4) did you install new head and base gaskets? Yes

What I should have done is just run it how it was or purchased an entire new top end but this ski is so old I don't want to put too much money into it; I have no idea the condition of the bottom end. Now I have a lot of time and a little bit of money but no running ski. Especially since the previous owner told me it "ran last summer".

BEFORE

AFTER

 

[Dr Honda]

Well... unless they are out of round... that jug looks good to me.

Go run it hard, and see if the compression picks up. Also... go get a different compression tool. Who knows... it could be wrong, or there could be a leak in it.

 

[B_PWC]

Well... unless they are out of round... that jug looks good to me.

Go run it hard, and see if the compression picks up. Also... go get a different compression tool. Who knows... it could be wrong, or there could be a leak in it.

Could be the compression tool; I got it at harbor freight ($10) for a 2 stroke Yamaha golf cart I was rebuilding.

I think at this point I will put it in the water and see if it runs; if so I will run it as much as I can before it requires more $$$. My expectations were pretty low when I bought it. I would like to get at least one season out of it; at this point I only have ~$700 invested in it (including trailer) and don't want to invest more in such an old ski.

Thanks for all the assistance.

 

[Dr Honda]

Don't knock the HF compression tools. I have 3 of them, (at the shop, tool box, and home) and they all work great. BUT... I checked them with shop air before using them. (make sure the gauge was right)

With that said... I do have a Snap-On gauge too. But it's too expensive to drop. So, it stays in the box.

Oh.... don't use the little 14mm adapter that it comes with. Just screw the tool into the sparkplug hole.

 

[B_PWC]

Don't knock the HF compression tools. I have 3 of them, (at the shop, tool box, and home) and they all work great. BUT... I checked them with shop air before using them. (make sure the gauge was right)

With that said... I do have a Snap-On gauge too. But it's too expensive to drop. So, it stays in the box.

Oh.... don't use the little 14mm adapter that it comes with. Just screw the tool into the sparkplug hole.

I actually buy a lot of stuff from HF, from trailers to hose clamps. They have a lot of great stuff and some stuff that should be avoided. The nice thing for me is that most of these tools I will only use 2-3 times in my life so the price can't be beat. They always give out 20% off coupons and free multi-meters which makes it even better.

Kind of off topic but was in no way knocking HF, they have lots of my money.

It was late last night when I was testing the rings. I am going to test them again on Thursday to see if I just didn't have the comp gauge sealed.

 

[B_PWC]

Ok... way off topic here but quick question.

1992 SeaDoo XP 587
It has had the oil bypass done to it before I got it but there is not any hoses or oil for the rotary gear; should there be? I have read elsewhere on here that the rotary gear still needs to be oiled.

What should I look for to ensure the bypass was done correctly?

 

[Dr Honda]

It's your thread... it can go any direction you want.

YES !!!!! The rotary valve gears need oil. The proper way to covert to pre-mix (oil bypass) is to remove the pump. and seal off the nipples on the manifold... but to leave the oil tank in the hull, and hooked to the rotary valve gears. That way, you can make sure they have oil. You won't ever need to add oil, as long as things are working, and not leaking. Some people put a loop of hose in the engine, and make sure that there is oil in it... but I don't recommend doing that way. If you have a leak, or if the center seals give up... you can suck out that little bit of oil quick.

 

[B_PWC]

Happy and embarrassed….

After leaving the ski alone for a day I decided to go back and check a few things before I put it in the water for the first time. When trying to figure out how the previous owner bypassed the oil pump I saw it. What a stupid mistake I had made. The oil bypass has a clear flexible tube that goes from one side of the engine to the other and it is a tight fit. When lowering the jugs over the piston I barely caught the edge of the tube so when I torque it to specs the tube got pinched leaving a very small leak between the block and top end. After tearing it all down and putting it back together, being a little more careful, I am getting equal compression of ~145 on each cylinder!!!

With the oiling system there is a clear tube (green line above) that runs from one side of the block to the other. I don’t see any oil in the tube; how should I add oil to it? Is it 2 stroke PWC oil?

 

[mshimon]

I just finished breaking in my ski with new rings and a hone. I used SBTs procedure, I haven't had any troubles at all.

SBT
Engine Break-In Procedure

These instructions apply to all models with the exception of the RFI, DI and 4-stroke equipped models. For the DI models, do not add oil to your fuel tank. For the new 4-stroke skis, we recommend you consult your Owner's Manual and follow the recommended procedures.

NONE of the engine break-in can be done out of the water!

Proper break-in of your engine is the most critical aspect for determining the longevity and performance of your engine. Engines not properly broken-in will often fail within the first minutes of operation. Ring failure and piston seizure are the most common symptoms of an improper break-in procedure.

If you have a pre-mix system (mixing oil and fuel in the fuel tank), then you should richen the ratio to about 32:1 for the first ten gallons of gas. If you have an injection system (putting oil in a separate oil tank), then you should put 50:1 premix in the fuel tank along with the oil injection system for the first ten gallons of gas.

During the first 10 gallons of gasoline, there should be NO full throttle operation. First idle the engine for about 10 minutes to ensure that the engine is properly warmed-up. Then begin varying the throttle position up and down, up to 20% throttle for a half hour. Then come back and let the engine cool off completely - it should be a good 30 min break. After it cools down, you may now ride it up to 50% throttle for another half hour or so. Then come back again and let it completely cool down again. Now you can go out and ride up to 90% throttle. Continue this for the remainder of the 10 gallons, never holding one throttle position for more than a few seconds. Do not run at a steady throttle position and do not go to 100% throttle. After your first tank of gas, replace your plugs with fresh ones. For the second tank, you may ride normally with one exception - do not hold it at 100% throttle for more than a few seconds. After the second tank of gas, you are completely broken in and may ride anyway you like.
Last edited by Ericka-SBT; 07-15-2008 at 10:25 AM.

 

[Dr Honda]

....

With the oiling system there is a clear tube (green line above) that runs from one side of the block to the other. I don’t see any oil in the tube; how should I add oil to it? Is it 2 stroke PWC oil?

Yes... it should be the same 2-stroke oil you are burning. Some people put a "T" fitting in the hose, and use that as a fill point. BUT... Like I said before... I don't like a loop of hose. If you have leaky RV or center seals... it will drink that oil, and you will destroy the gears. Put the tank in the hull. and hook those hoses to it. Then... keep a quart or two in the tank.

 

[IDoSeaDoo]

To add to the break in procedure: I heard you're not supposed to use synthetic oil during break-in. I heard that it'll get into the cracks of the hone scars and prevent the rings from seating properly...

 

[stevemacd]

sorry to post in a super old thread but by any chance would you happen to remember how much this job ended up costing you and roughly how much each thing was?
thanks

 

[IDoSeaDoo]

sorry to post in a super old thread but by any chance would you happen to remember how much this job ended up costing you and roughly how much each thing was?
thanks

these days, you can get a pair of WSM pistons for roughly $130, and those should come with rings and wrist pins and pin clips. If you want just rings, I believe they're roughly $30/piston. I'd replace the wrist pin bearings while at it, I've had one let go and total a motor once.

 

[stevemacd]

ohh thats not too bad im going to be replacing the rings, pins, and bearings in my gtx so thats why i ask. Maybe pistons too i haven't decided

 

[IDoSeaDoo]

cool deal. make sure you hone the cylinders and follow the break-in procedure. it can be found on this forum as well as the SHOBSBT.com FAQ. Oh and... don't twist the cylinder too much on when your piston is in it as you're seating the jug. I did that and caught the ring on a port and snapped it off, you'd be surprised how EASY that is to do. They are made of EXTREMELY BRITTLE material.

 

[stevemacd]

yea i will follow them very closely and ok thanks for the tip i will try to watch for that.