CRF Piston ?

[TLXR]

Is anyone changing the piston every 15 hours like Honda recomends? I have not seen any discussions on the subject.
For the YZF owners what does Yamaha recomend for your bikes, I know 426 owners with 2 years on the stock piston.
Thanks for any info
Terry

 

[Antman]

That very subject is being covered right now on Thumpertalk. Basically, No. Nobody I know of is changing it that often. I have over 40 hours on mine. The piston is skirtless,though, and possibly more prone to getting loose. I may change mine twice a year rather than once a year like I had originally planned. I am going to start compression testing it once a month to track its compression and go from there. It feels like I just broke it in. I can't imagine replacing the piston already.

 

[dheard4992]

piston

a guy at thumpertalk says he has over 1000 miles on enduro odometer and hasnt touched crf yet.

 

[ochster]

I know of a new, never been rode CRF, that just did 1300mi. on a baja ride. Literally the guy installed bars and a tank, and left the next day. There was no maintenance pulled for a couple day's, and it started making a little noise. At that point the oil was changed daily, while the motor got noisier by the day. On the last leg of the ride, it sounded like it was coming apart. Makes me cringe, good thing it's a Honda!

 

[dirtbikedad]

I have about 2000 miles on my '00 WR400F. The piston is original and no sign of any problems yet. My saving grace may be that I don't like to run the engine near max RPM. I just short shift and use the torque.

Jerry

 

[RYDMOTO]

Not to get off topic here.....but I did hear of an interview of a man who owns a Volvo with over2,000,000 miles on the engine.All original pistons,rings and bearings! It does say something about the selection of the right metals etc.I have read somewhere that Volvo uses a higher nickel content when casting their blocks.Today I read in Dirt Rider how Honda's CRF they will be racing this year has some super exotic metal being used in the exhaust header pipe.Its thinner than a buisness card yet stronger that stainless and titanium.Pretty amazing.And with todays coatings on our dirt bike cylinders that last almost forever,I am wondering when a long lasting piston will come out.

 

[Rich Rohrich]

Originally posted by RYDMOTO
I am wondering when a long lasting piston will come ut.

They exist in lots of places. XRs, japanese auto engines, Detroit V8s etc. If you want super light bikes with high specific output per liter we will see increasingly higher engine speeds and weight saving engineering. High speeds and high output calls for light parts that won't last as long. Treating a CRF like an XR or even a YZF will make for some pretty unhappy owners.

You can count on the fact that a year from now we'll hear a never ending stream of CRF owners belly-aching about engine damage caused by their attempts to stretch the maintenance intervals. The YZF250 owners are finding out that cranks don't last forever just because they ride four-strokes. The CRF guys might want to take notice.

The CRF may be a Honda but it's not an XR. (thankfully)

 

[RYDMOTO]

Very good point Rich.....But I do wonder what NASA has been using that has yet to trickle down to us earthlings : )Metal wise that is.

 

[Sage]

I'm sure 10 piston changes would cost less than a stray rod cutting your engine in half, if you want fast stuff you must pay the price, and if Honda used a 2,000,000 mile volvo piston in your crf it would run like a volvo. new four stroke's are performing at levels that will require more than just a oil change and valve adjustment every now & then, enjoy the power but keep up on the maintience or it will cost you big $$$.