Engine rebuild time

D

David Mcfadzen

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Joined
Jan 20, 2017
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35
Location
New Brunswick
I'm planning on freshening up my engine on my 03 sx viper this summer, it currently has 26k km on it and starting to feel a bit tired. Curious if there is anything else I should do besides piston, rings and wrist pin bearings. I also will do crank seals and opti cool head gasket while its apart but is there anything else I should replace while its apart? I Would also like to get your opinions on brand of pistons to choose, I am leaning towards oem yamaha parts as they lasted this long already and want to keep my machine as reliable as possible. My local dealer wants 920 canadian for the 3 pistons, is that my best option and if so is there a cheaper place to buy oem parts other than my local dealer? Thanks for your advice, Dave
 

used spi pistons with good sucess on my brothers 02 viper but his was one of the ones that did in the connecting rod bearing and his was ritch at the time too.
 
If you are doing all that I would do the water pump seals while you are in there.
 
David Mcfadzen said:
I'm planning on freshening up my engine on my 03 sx viper this summer, it currently has 26k km on it and starting to feel a bit tired. Curious if there is anything else I should do besides piston, rings and wrist pin bearings. I also will do crank seals and opti cool head gasket while its apart but is there anything else I should replace while its apart? I Would also like to get your opinions on brand of pistons to choose, I am leaning towards oem yamaha parts as they lasted this long already and want to keep my machine as reliable as possible. My local dealer wants 920 canadian for the 3 pistons, is that my best option and if so is there a cheaper place to buy oem parts other than my local dealer? Thanks for your advice, Dave
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Are those 26k on the initial stock pistons and rings, or have they been replaced at some point before?

I've heard that you should do pistons and rings at around 10k (6k miles) but that might be unnecessary early then maybe?
 
kirkswim said:
If you are doing all that I would do the water pump seals while you are in there.
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this is my brother. he did not have 8000km on his when the bearing let go and mangled the piston. the others where probably good but we replaced all 3 at the time to make sure it was balanced correctly. water pump seals would not be a bad idea and a check of all the lines while engine is out as some might need replacing as thjey are getting hard with age.
 
I believe that it has original pistons in it. Thanks for your info and advice however I will be going stock even though the parts are much more costly than "ebay" its much better insurance and confidence knowing its oem parts for travels around my province. Cheers
 
Replace the thermostat as well. I had some bad luck with that.....season after I redid the the top end in my SRX the t-stat collapsed while I was running the sled on the hard side and had the center and mag side pistons melt, I also replaced the coolant sensor as well, it never went off indicating an overheat, I had mixed the coolant properly and 3 times removed any air in the coolant system, 2nd time I checked for air in the system was the last I saw any bubbles and put on 1200 miles after that with 0 issues, even held it to the bar a few times just to see my 2000 SPEEDO go to 120mph lol while continuing to ride to the next trail
I used SPI pistons, the PTO side was in perfect condition and compression was 145, right where it was after the rebuild, I was using 94 octane as well. and am jetted a little rich.
I weighed the SPI pistons against the oem as well, the SPIs were were very close to the oem weight only slightly heavier, as they should be without any wear, but were all the same weight, my scale reads down to .01 grams
 
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the oem yamaha are the best quality pistons you will find......bar none. they are a forged powder piston, very strong with very minimal expansion. this allows them to be run at a tighter skirt to wall clearance allowing less rocking of piston in bore. yamaha rings are also excellant quality. save up your money and buy the good ones, thats why you got that may miles out of it the first time!


by the way, just FYI to eveyone with a triple. Buy a set of pistons soon as you can see the prices are going up and up. this is because the sleds are now 20+ yrs old. yamaha keeps raising the prices as stock goes lower, then they discontinue them like the vmax4 pistons and such.
 
David Mcfadzen said:
I'm planning on freshening up my engine on my 03 sx viper this summer, it currently has 26k km on it and starting to feel a bit tired. Curious if there is anything else I should do besides piston, rings and wrist pin bearings. I also will do crank seals and opti cool head gasket while its apart but is there anything else I should replace while its apart? I Would also like to get your opinions on brand of pistons to choose, I am leaning towards oem yamaha parts as they lasted this long already and want to keep my machine as reliable as possible. My local dealer wants 920 canadian for the 3 pistons, is that my best option and if so is there a cheaper place to buy oem parts other than my local dealer? Thanks for your advice, Dave
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Got to love the price of Yamaha parts up here. Rings aren't cheap either. I purchased used stock Oem pistons fro my rebuild that were within spec. Still running them now after 7k. I was going to go the aftermarket route as the cost of OEM made me balk at sinking over 1500 into a rebuild on a sled thats worth 2-2500. I purchased the pistons from members on this site.
 
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