I've been riding my 09 yz450f for the last 3 seasons and its got about 60 hours on it now. Its got the normal snowbike specific mods done to it and overall I like the bike. Runs perfect. Starts easy. Etc. Part of me says just to freshen it up. Another part says go with a big bore, cams, pipe etc and really throw some money at the motor to get some more power. Or the third option is to upgrade to a newer bike like maybe a 14 or newer bike of unknown brand... I'm not brand loyal at all on bikes. So as always its the old, what would you do? TIA
Big Bore YZ450F or Upgrade?
- Thread starter polarisfornow
- Start date
I know the 14+ is about 10 more HP stock for stock... but even considering a bored out 09 it would still be that much better?
M
A buddy of mine did a BB on an 08. Cant remember which kit, Cylinder Works maybe, anyways it didn't make much difference and he only got about 40 hours out of it before it started smoking. Rebuild it stock or get a newer fuelie YZ. IMO
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Pretty happy with my high compression standard bore cylinder/piston kit.
M
How many hours on your single ring piston, I'm at around 85 on the stocker and I will be doing the top end this fall.
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C
dont forget the bottom ends guys!!!
not only does that crank also have 40 hard hours, but now its getting a big bore kit to beat it up even harder.
100% upgrade bikes to a newer model. the tech improvements on them are amazing.
not only does that crank also have 40 hard hours, but now its getting a big bore kit to beat it up even harder.
100% upgrade bikes to a newer model. the tech improvements on them are amazing.
A
What's the '14 and up YZ got for power over the '10-13 models? I have an '11 YZ450 that runs great, but like all bikes could use more snort in the snow.
M
There isn't that much difference really, maybe 4-5 hp. I run an 11 that I bought basically brand new last season. The 10-13s have a few benefits over the 14+. The first is price, they are dirt cheap because nobody is racing them anymore, the second is after market parts. I've been buying brand new parts at about 30% of retail. The last thing I like about the 10-13 is the pigtail pipe, no more burnt pants, cracked pipes and its very easy to fully shroud. I picked up a brand new GYTR head and cams and ran it with a tune last year. It runs stronger than my buddies 17 YZ450FX also tuned. With the head and cams Yamaha claims over 60hp on the 10-13 so its right in the game. FYI the 10-13 can be updated with the newer oiler system as well. Its basically the same motor as the 14+ the biggest changes were in the chassis which makes no difference on the snow.
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M
Just an update on the whole piston vs hours thing. A second 2017 YZ450 FX that a friend has with 112 hours went down last spring and it just got opened up also with a cracked stock piston. So for us that's two cracked pistons on 2 bike failures one cratered at 108 hrs and the second at 112 both cracked the piston in a direct line with the pin. I will see if I can find the pics
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Temps are always good and monitored by gauge and religious oil changing. I found the pics but it wants me to resize them, maybe later, don't have time right now.
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P
So based on that we could say that 100 hours are save -- anything more you are riding a time bomb. That is only reasonable for the high Hp running that snow bikes do. By the way almost every GYTR upgraded bike I know of had the GYTR piston crack and ran flawless with the stock pistons. Bouncing of the rev limiter is hard on pistons no mater how you slice it. I will change my piston out before 100 hrs. On my woods single track bike 200+ is no problem at all.
M
Yep, seems 100 hrs is the max number. The GYTR single ring piston is a high comp lightweight piston. Its a sprinter not a long distance runner. When I installed my GYTR head and cams I thought long and hard about the piston and decided I just didn't want to change it every 25 hrs which is the recommended interval on dirt.
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