JeremyD615
Well-Known Member
Yeah, you definitely need to replace the pistons with a size up...
2000 Sea-Doo gts oil change
- Thread starter JoeStetor1
- Start date
- Status
JoeStetor1
Member
I am going to send my cylinders to SBT and they will send me two in return with the piston and ring kit. Good choice?
JeremyD615
Well-Known Member
That’s the quickest way to get it up and running, but there are better options out there as far as the quality of parts goes. It’s fine for a recreational ride in my opinion, but I’d go another route if you’re going to be modding at all in the future.
JoeStetor1
Member
I'm going to use this ski for my fiance and or her son. I'm going to get a bigger one for myself so the cylinder swap will be best for me on this one.
JoeStetor1
Member
Seadoo 717 720 Rotax Engine Top End Rebuild kit Cylinders Pistons $150 REFUND | eBay
Seadoo 717 720 Rotax Engine Top End Rebuild kit Cylinders Pistons $150 REFUND | eBay
JeremyD615
Well-Known Member
That’s probably a higher quality piston, but I have no idea who that is doing the machine work...
JoeStetor1
Member
I finally got around to rebuilding this top end. I got the SBT kit. I got a little over zealous on filing the first ring gap. It calls for .013 and I ended up with .020. This was the bottom ring. All the other rings I got the gap perfect at .013. should i order another ring or leave the one at .020?
Also I noticed some 2 stroke oil in the crankcase. Is that ok?
Do i need to do anything to these cylinders besides washing them down before install?The piston booklet said something about chamfering ports. I thought SBT did all that with the cylinder boring and what not.
You better buy all new rings because you never file these rings.
This is not like a 4-stroke engine with file fit rings.
If the gap is out of spec then the machine shop did not bore the cylinders correctly.
Again, if the ports were not chamfered then the machine shop did not do their job.
This is not like a 4-stroke engine with file fit rings.
If the gap is out of spec then the machine shop did not bore the cylinders correctly.
Again, if the ports were not chamfered then the machine shop did not do their job.
JoeStetor1
Member
Attachments
JoeStetor1
Member
In the SBT installation guide it told me to set the ring gap by filing one end of the ring. It also gave me a chart for the two stroke section. I'm at odds.
WOW! I can't believe the ports on those cylinders. They were not chamfered at all and SBT should be ashamed of sending them out that way.
You are absolutely going to have to chamfer them or you will at best wear out the rings really fast or more likely snag a ring and ruin everything.
I have been rebuilding these since the early 90's and have never seen a reputable shop send cylinders without chamfering the ports.
It has to be done and done correctly at the correct angles and in my opinion not a basic first time DIY.
Second, as far as ring gaps..... I have been rebuilding 2-strokes since I was 14 in 1990 and never once heard of file fitting 2-stroke rings, ever. If the bore was bored and honed correctly to fit new oversized pistons at the correct clearance there is no reason the rings should have to ever be touched.
In my opinion both of these issues are due to either poor machining and/or poor part quality. If what you are showing and saying is what SBT is saying and shipping out I will not be suggesting any users here use their cylinder exchange service.
The ring gap for new rings per the 720 factory manual are 0.001-0.016 so new rings should never have to be touched. Also the manual says absolutely nothing about filing rings.
You are absolutely going to have to chamfer them or you will at best wear out the rings really fast or more likely snag a ring and ruin everything.
I have been rebuilding these since the early 90's and have never seen a reputable shop send cylinders without chamfering the ports.
It has to be done and done correctly at the correct angles and in my opinion not a basic first time DIY.
Second, as far as ring gaps..... I have been rebuilding 2-strokes since I was 14 in 1990 and never once heard of file fitting 2-stroke rings, ever. If the bore was bored and honed correctly to fit new oversized pistons at the correct clearance there is no reason the rings should have to ever be touched.
In my opinion both of these issues are due to either poor machining and/or poor part quality. If what you are showing and saying is what SBT is saying and shipping out I will not be suggesting any users here use their cylinder exchange service.
The ring gap for new rings per the 720 factory manual are 0.001-0.016 so new rings should never have to be touched. Also the manual says absolutely nothing about filing rings.
Last edited:
JoeStetor1
Member
Do you need better pictures or are you sure they are not done correctly? Some do have an angle on them. I just want to make sure we are on the same page.
JoeStetor1
Member
Yes. They do have sharp edges.
JoeStetor1
Member
I will take the cylinders to have them chamfered. The rings where at .012 gap out of the box. The Pistons are .5mm. should I just order new rings and roll with the .012?
JoeStetor1
Member
This is the chart they sent me.
Attachments
JoeStetor1
Member
I see. I misplaced the decimal. Thank you.
- Status
Similar threads
