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CR 80 Piston, Honda OEM or ?

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My son desert races a CR80 expert and we have had the last 2 pistons come apart and cause the bottom end to sieze. Niether piston has had over 8 hours on it. We usually buy the top end kits and pistons and by the six pack and change them about every 15 hours of ride time, I was wondering if any one has tried the Wiesco pistons and what kind of luck you have with them?

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My son desert races a CR80 expert and we have had the last 2 pistons come apart and cause the bottom end to sieze. Niether piston has had over 8 hours on it. We usually buy the top end kits and pistons and by the six pack and change them about every 15 hours of ride time, I was wondering if any one has tried the Wiesco pistons and what kind of luck you have with them?

you may get a little more life out of a wiseco,maybe. the 80 has its limits and i see them rung out at every track i go to. if youre not getting anymore then 8 hours on a topend/piston,then you may have a starvation issue. the 80s are alot of fun but at the end most kids are just flat out riding the pi$$ out of them. whats your mix ratio and what type of oil are you using in the gas?

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My son desert races a CR80 expert and we have had the last 2 pistons come apart and cause the bottom end to sieze. Niether piston has had over 8 hours on it. We usually buy the top end kits and pistons and by the six pack and change them about every 15 hours of ride time, I was wondering if any one has tried the Wiesco pistons and what kind of luck you have with them?

you may get a little more life out of a wiseco,maybe. the 80 has its limits and i see them rung out at every track i go to. if youre not getting anymore then 8 hours on a topend/piston,then you may have a starvation issue. the 80s are alot of fun but at the end most kids are just flat out riding the pi$$ out of them. whats your mix ratio and what type of oil are you using in the gas?

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Were running motul at 32:1 and he does run the t mortal pi$$ out of it. We have two motors for it that we go through and swap out before every race. His races may be 30 miles or it may be up to 75 miles. These motors are probably over maintined. I haven't had any problems until the last 2 pistons one in each motor.

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Maybe bump your mix ratio up to 20:1 and jet accordingly. Maybe, since it is ridden so hard, it needs a little extra lubrication.

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My son desert races a CR80 expert and we have had the last 2 pistons come apart and cause the bottom end to sieze. Niether piston has had over 8 hours on it. We usually buy the top end kits and pistons and by the six pack and change them about every 15 hours of ride time, I was wondering if any one has tried the Wiesco pistons and what kind of luck you have with them?

This is something that happens to lots of people before they try Wiseco. Cast pistons are brittle and can't be run for too long. Unless OEM, Wiseco's have warranties and you can actually call the company and talk to a person.

Here's your solution: Never ever ever ever ever buy an OEM, Pro-x or other wise cast piston again. Problem solved.

You could do easy 30 hour intervals and do a re-ring every 15. The forged piston will not come apart like a cast so you can run them until they slap around and get too much clearance.

Good luck!

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you may get a little more life out of a wiseco,maybe. the 80 has its limits and i see them rung out at every track i go to. if youre not getting anymore then 8 hours on a topend/piston,then you may have a starvation issue. the 80s are alot of fun but at the end most kids are just flat out riding the pi$$ out of them. whats your mix ratio and what type of oil are you using in the gas?

Oil starvation does not cause pistons to crack. Its a piston issue not oil. Bit he should run more oil.

Were running motul at 32:1 and he does run the t mortal pi$$ out of it. We have two motors for it that we go through and swap out before every race. His races may be 30 miles or it may be up to 75 miles. These motors are probably over maintined. I haven't had any problems until the last 2 pistons one in each motor.

Exactly this is not an oil issue its a piston issue. Go Wiseco and maybe bump your oil up to 24:1 or more. Those 80's need lots of oil!

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Thanks for the replies, I will be completely rebuilding the motors over the next couple of days and will keep you posted on the results. BTW I talked to one of his sponsors and he reccommended going to 24:1 as well.

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also make sure the bore is the correct size for the piston!!!

sounds like you are not installing the correct size piston for the bore and it rattles and then shatters.

Wiseco has their own specs for the clearance, so be sure to setup the motor accordingly

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I have 4 cylinders for the 2 motors and I have them checked everytime I swap them out and apparently they still check out. As one can tell I"ve spent a fortune on parts for this bike. I can't wait till next year when he steps up to the big bike.

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apparently they still check out.

confidence inspiring there!

Basically you are saying you have no idea I gather. MEASURE MEASURE MEASURE

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confidence inspiring there!

Basically you are saying you have no idea I gather. MEASURE MEASURE MEASURE

Your correct, I walk into the shop that sponsors my son and say "Hey check this cylinder and if its bad I need another one and if its good give me the appropriate parts." Their response determines what happens next. They know I don't care if its 1 dollar or 1000 dollars tell me the truth because I don't scrimp. These guys know I want my son on the best possible machine he can be on, He is not out there riding moto he is out in the middle of the desert pushing himself and his bike as hard as he can.

Edited by RunningC

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It's been stated, fatigue is the problem. Wiseco's have a longer fatigue life than cast pistons. The piston skirt to cylinder wall clearance has a large effect on the stress the piston sees. Larger clearances shorten the fatigue life of the piston but they also improve the pistons resistance to seizing failures related to overheating or detonation. You can try tightening up the clearances towards the minimum (that means starting with a new cylinder or sleeve) but if you start seizing pistons you'll have to accept that 80's and desert racing just aren't made for eachother. If your piston life is 8 hours, then change them at 6.

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It's been stated, fatigue is the problem. Wiseco's have a longer fatigue life than cast pistons. The piston skirt to cylinder wall clearance has a large effect on the stress the piston sees. Larger clearances shorten the fatigue life of the piston but they also improve the pistons resistance to seizing failures related to overheating or detonation. You can try tightening up the clearances towards the minimum (that means starting with a new cylinder or sleeve) but if you start seizing pistons you'll have to accept that 80's and desert racing just aren't made for eachother. If your piston life is 8 hours, then change them at 6.

Word.

Chucking that OEM piston into the garbage and installing a WIseco or another forged piston is the EASIEST way to prolong the life of your motor. But sadly some people have a phobia or something that I just for the life of me can't understand and they have to run OEM or a cast piece of crap.

I don't get it. To the OP just buy a wiseco and your problems will be over.

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Well the problem is that people put the Wiseco in thinking it will last forever. I get 20 hours on the Wiseco in my CR250 before I get excessive wear of the skirt. I have seen some seriously excessive wear but have never shattered a piston. You can clearely see the bottom edge of the intake port imprinted on the skirt, that is how deepely worn the piston is. There is some extra scratching and debris related wear though because this piston came out after a crankshaft failure. I never get any blowby because my rings never get a chance to wear out. The bike runs the same as day one on the day I replace the piston. I just know that if I let it go longer I risk shattering it. I keep an eye on the wear by regularly inspecting the piston through the ports.

I feel that I would have seen a few failures with cast pistons with this kind of wear going on.

DSCF2096.jpg

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i got my 01 cr 80 5 months ago and we rebuilt it 3 months ago and used a namura piston, its been fine for 3 months and i ride it hard almost every day, we are going to do another rebuild soon and may try a weisco to see how they hold up

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