offgrididaho
Member
So I'll try and answer some questions. But locate your part numbers with the factory microfiche - Sea-Doo
Thanks.....
You measured 87.9 mm on the piston. That is Stock bore of 88mm. So to answer the next question about the score marks on the pistons, if you're other measurements are correct, it appears the bores are tapered-ish. I would not even care what those pistons looked like, you need to bore the top end and start with fresh pistons. How many original hours are on the engine, should be on the gauge. If you're around 200 hours, it's time. The 10 hours on the previous rebuild doesn't matter, that was just a band-aid with how those bores measured.
245hrs
I sent the crank, cyls and head off to be redone. The boring shop will tell me the size pistons to buy and I will send them to him for measurement and wall clearence. The two types require different clearences .0035-.0075
Sealant for cases, Threebond 1211, hondabond, yamabond but ABSOLOUTELY DO NOT USE 518 for the case halves. Almost 20 years ago I chased an engine in my Speedster that kept eating pistons. Paid someone to rebuild the engine, same problem 4-6 hours each time. I rebuilt the engine and did a leak down test. Couldn't pass a leak test. Called GroupK, was told to use Threebond 1211. I have never looked back and have rebuilt/restored many skis. 518 is a 100% hardpass. I use it other places on the build but never on case halves.
Three shops have said to use the 3bond1211, so thats what Ill use.
I also use Threebond on the base gaskets, you are literally just using enough to seal it. I use my finger and wipe it on the gasket surfafce. The gasket should still show green.
Got it, thanks.....
Rave valves leaking, use the 951di o-rings on the stems of the rave valves. They are green. I would replace the valve too if they are leaking along with the housings. OEM ONLY no China junk.
The dealers only go back 10 years for parts so where can I buy new rave valves and housings?
Starter, I don't think I have ever seen a 951 starter fail. They are not like the other seadoo starters. I personally wowuld not even open that starter. My 1986 Honda ATC three wheeler uses the same style starter. It has been under water more times than I care to admit and it's still the original one.
OK I wont touch it. What about the small case bearing and bendex?
Crankseals, why even worry about how the used ones are on then crank. You're having the crank rebuilt and using new ones. I know, you want to know all the whys and why nots, I get it but honestly sincec you're fully rebuilding.....that is out the window for me. As far as other gaskets, I would try and find a genuine seadoo gasket set. I loathe aftermarket gaskets. Complete gasket set PN: 290888131. There is one on Ebay, and it is not complete.
Ill try to track down oem.
Clean or blast cases. Personally, those liik really nice I would leave then. BUT if you insist on blasting, you will need a 2K primer. I have used Eastwood's 2K in a can. Worked awesome. Remember to scuff with a scotch brite before painting. I went to my loacl body shop supply house and got a pint of paint to paint engines before. You cacn use Duplicolor Wheel paint. Any paint will hold up, it does not need to be high temp. But just keep it washed and clean and lubed afterwards and it will last. I blast all my cases, but I buy salt water shitboxes to restore so the cases and paint are really roached out.
Im just going to clean them they are in good shape. Fresh water only. Can I use a tub and gasoline with a brush?
Pistons for the rebuild, let the machine shop decide what size you need. I would use OEM pistons or Wossner pistons.
I will send pistons to bore shop once they tell me what size I need.
Dont think I can buy oem, ill look, wossner are available but only in .50,1mm. No .25mm and .75mm. They also have to bore the wall/piston clearance different. Plus I have read they take much longer to expand and the engine has to be hot before running wot.
You will need to measure the squish gap after you get the bottom end together. Procecss is in the factory service manual. I use the solder method.
Yes I have done it before, so Im good there.
Carbs, GENUINE MIKUNI kits and needle and seats with viton tips. This should be the mikuni part# for the rebuild kit, Mikuni BN46I seadoosource.com and go to the cacrb reference to get the needle and seat size for your year ski.
Yes I am aware mikuni only. Thx
Cleaning the water passage, Harbor freight wire brush for drill SKU: 71054. Works like a champ.
Could I just use some low strength acid like vineager?
Thanks.....
You measured 87.9 mm on the piston. That is Stock bore of 88mm. So to answer the next question about the score marks on the pistons, if you're other measurements are correct, it appears the bores are tapered-ish. I would not even care what those pistons looked like, you need to bore the top end and start with fresh pistons. How many original hours are on the engine, should be on the gauge. If you're around 200 hours, it's time. The 10 hours on the previous rebuild doesn't matter, that was just a band-aid with how those bores measured.
245hrs
I sent the crank, cyls and head off to be redone. The boring shop will tell me the size pistons to buy and I will send them to him for measurement and wall clearence. The two types require different clearences .0035-.0075
Sealant for cases, Threebond 1211, hondabond, yamabond but ABSOLOUTELY DO NOT USE 518 for the case halves. Almost 20 years ago I chased an engine in my Speedster that kept eating pistons. Paid someone to rebuild the engine, same problem 4-6 hours each time. I rebuilt the engine and did a leak down test. Couldn't pass a leak test. Called GroupK, was told to use Threebond 1211. I have never looked back and have rebuilt/restored many skis. 518 is a 100% hardpass. I use it other places on the build but never on case halves.
Three shops have said to use the 3bond1211, so thats what Ill use.
I also use Threebond on the base gaskets, you are literally just using enough to seal it. I use my finger and wipe it on the gasket surfafce. The gasket should still show green.
Got it, thanks.....
Rave valves leaking, use the 951di o-rings on the stems of the rave valves. They are green. I would replace the valve too if they are leaking along with the housings. OEM ONLY no China junk.
The dealers only go back 10 years for parts so where can I buy new rave valves and housings?
Starter, I don't think I have ever seen a 951 starter fail. They are not like the other seadoo starters. I personally wowuld not even open that starter. My 1986 Honda ATC three wheeler uses the same style starter. It has been under water more times than I care to admit and it's still the original one.
OK I wont touch it. What about the small case bearing and bendex?
Crankseals, why even worry about how the used ones are on then crank. You're having the crank rebuilt and using new ones. I know, you want to know all the whys and why nots, I get it but honestly sincec you're fully rebuilding.....that is out the window for me. As far as other gaskets, I would try and find a genuine seadoo gasket set. I loathe aftermarket gaskets. Complete gasket set PN: 290888131. There is one on Ebay, and it is not complete.
Ill try to track down oem.
Clean or blast cases. Personally, those liik really nice I would leave then. BUT if you insist on blasting, you will need a 2K primer. I have used Eastwood's 2K in a can. Worked awesome. Remember to scuff with a scotch brite before painting. I went to my loacl body shop supply house and got a pint of paint to paint engines before. You cacn use Duplicolor Wheel paint. Any paint will hold up, it does not need to be high temp. But just keep it washed and clean and lubed afterwards and it will last. I blast all my cases, but I buy salt water shitboxes to restore so the cases and paint are really roached out.
Im just going to clean them they are in good shape. Fresh water only. Can I use a tub and gasoline with a brush?
Pistons for the rebuild, let the machine shop decide what size you need. I would use OEM pistons or Wossner pistons.
I will send pistons to bore shop once they tell me what size I need.
Dont think I can buy oem, ill look, wossner are available but only in .50,1mm. No .25mm and .75mm. They also have to bore the wall/piston clearance different. Plus I have read they take much longer to expand and the engine has to be hot before running wot.
You will need to measure the squish gap after you get the bottom end together. Procecss is in the factory service manual. I use the solder method.
Yes I have done it before, so Im good there.
Carbs, GENUINE MIKUNI kits and needle and seats with viton tips. This should be the mikuni part# for the rebuild kit, Mikuni BN46I seadoosource.com and go to the cacrb reference to get the needle and seat size for your year ski.
Yes I am aware mikuni only. Thx
Cleaning the water passage, Harbor freight wire brush for drill SKU: 71054. Works like a champ.
Could I just use some low strength acid like vineager?
