Picked up a YFZ450R today!

[oscarmayer]

the 450R gets hot for 3 reasons.
1- it is not designed to run slow. either run it on a MX track and I mean run it or shut it off.
2- the stock 12.5:1 compression does run hot and any engine will
3- did I say your running it too slow? try spending $100 on an upgraded bigger racing radiator off ebay and that will help some.

I own a 2011. it gets freakin hot especially when you ride it "putting around" instead of on an open track and ripping it.

[BOB MARLIN]

The stock compression is 12.5:1 ? I had no idea. How do these things run as good as they do on 91 octane ?. I always thought they were around 11.4 or so, witch is still a bit high for 91.

[Fox250R]

I find it real interesting that the dealer where I bought my 450 from has no idea what an Air Induction System is.
But in this picture I found on yahoo.............


2014 Yamaha YFZ450R Engine GYTR



Thanks a lot Yamaha. LOL

[BOB MARLIN]

Did this thing ever get fixed?.

[6speedthumper]

^^^what he said^^^

[Fox250R]

Did this thing ever get fixed?.

Nope still has the bog. Its ridiculous!

[Fox250R]

Took the YFZ to sand lake on Wednesday! No Paddles but it still did very vey well actually. I took it down a few tree shots and had no prob getting out even with dirt tires. Still has the low end bog and died on me many times. Will be taking it to get Dyno tuned in the next few weeks to see if I can get rid of this annoying bog!

[rdonald1979]

I have an old 426 and to get rid of the low end bog/stall I put an aftermarket accelerator pump on it (Boyesen). Worked well.

[Darius1502]

I had a 1998 YZ400F (which was the first iteration) of this motor....the head pipe did the EXACT same thing. Totally normal...but takes some getting used to!

[oscarmayer]

the bog is somethign in the EFI system. you will have to get a programmer to remove it. that is what we did and worked awesome!

but agian get the larger radiator and it will help a lot with heating issues. for $100 shipped that is CHEAP insurance..

[Fox250R]

I just installed a $700 Vortex racing ECU and it fixed everything.

Just got my new powder coated black rims today

[BOB MARLIN]

Did Yamaha stand behind anything ?. Its too bad you had these problems. The YFZ is an amazing quad.

[Fox250R]

Did Yamaha stand behind anything ?. Its too bad you had these problems. The YFZ is an amazing quad.

Well kinda, they tried their hardest to figure it out but never could! But now it's being said that messing with the TPS Throttle positioning sensor fixes the problem but I have yet to see anyone with a 2014 or 15 come out and say so. The whole situation was a bunch of bs if you ask me but after installing the vortex ecu everything is perfect now. Sad I had to spend another 2k on top of what I paid for the bike to fix something that never should of been an issue in the first place! And now I've been reading that buying an 09-13 ecu will fix the problem also and you can get a used one for around 100 lol owell live and learn right?

[yaegerb]

I just installed a $700 Vortex racing ECU and it fixed everything.

Just got my new powder coated black rims today

jeebus, I thought I had a big garage....is that yours or a storage facility? I can see four single stalls.......

[Fox250R]

jeebus, I thought I had a big garage....is that yours or a storage facility? I can see four single stalls.......

LOL, yah I have this one and the one to the right. Its just our garages where we live.
Fits my R the YFZ and a few other things with no prob

But would love something bigger lol