YZF's same/easy as CRF's to rebuild?

[Indetrucks]

Hey guys...

I currently have an 05 CRF250R and am looking to add a 2007 YZ450F to my stable (getting a killer deal on one)

Questions:

1) Are the top ends of the YZ450F's as easy to rebuild as the CRF's? I have done a few top ends on the CRF and re-ringed it as well. It's been apart enough for me to be familiar/comfortable working on it without a manual.

I guess what I'm asking is, am I going to have to re-familiarize myself with a whole new type of engine (rebuild process), or are they both pretty much the same (to an extent)? I understand there will be slight changes, which one is more complicated?

2) We usually throw new rings in the CRF250's at 30-40 hours, what is the interval for the YZ450F's for rings/rebuilds ?

3) Is the 2007 YZ450F a good bike or should I go for a diff. year?

Thanks guys!

[grayracer513]

The '07 is one of the new aluminum frame models, and is a good bike. The '08 turns a bit better, but a lot of guys like the '06 and '07 the way they are. Some change the clamps to 24mm offsets, some more. There are little power differences between the '06, '07, and '08.

Most YZ450's of any year will fairly easily go 70-120 hours with rings no matter how you ride them, and the valve relabilty will leave you wondering how they do it one the one hand, and why no one else seems able to on the other. My oldest '06 is almost 2 years old and is over 100 hours now, and it isn't going to be rebuilt anytime soon by the looks of things. The '03 that I had had over 350-375 hours on it, and is still running fine as far as I know.

But yes, they are about as easy to overhaul as any modern thumper.

[Indetrucks]

The '07 is one of the new aluminum frame models, and is a good bike. The '08 turns a bit better, but a lot of guys like the '06 and '07 the way they are. Some change the clamps to 24mm offsets, some more. There are little power differences between the '06, '07, and '08.

Most YZ450's of any year will fairly easily go 70-120 hours with rings no matter how you ride them, and the valve relabilty will leave you wondering how they do it one the one hand, and why no one else seems able to on the other. My oldest '06 is almost 2 years old and is over 100 hours now, and it isn't going to be rebuilt anytime soon by the looks of things. The '03 that I had had over 350-375 hours on it, and is still running fine as far as I know.

But yes, they are about as easy to overhaul as any modern thumper.

wow, sweet... good to know!

I mean, I understand the smaller bore of my CRF250 and the constant high reving of the motor puts a lot of stress on it, but re-ringing it every 30hrs and top end at 60-80 is getting kinda old.

I look forward to not having to do it as often

I just don't like the pain the the arse oil changes on the YZF's. My roomate has an 05 YZ250F and it seems to take way more time to do then on my CRF250. (oil in the frame or something?) Are the 07's still like that?

[grayracer513]

It takes me about 10 minutes to change the oil in mine, including cleaning the oil filter. The YZ450 is still a dry sump engine, but the oil tank is no longer in the frame, and there are no more external oil lines. The "tank" is now built into the front of the engine.

[Indetrucks]

It takes me about 10 minutes to change the oil in mine, including cleaning the oil filter. The YZ450 is still a dry sump engine, but the oil tank is no longer in the frame, and there are no more external oil lines. The "tank" is now built into the front of the engine.

Oh awesome! That was the only drawback I was creating in my mind. I know having those additional external oil ines have been known to leak.

COol! Thanks!

[grayracer513]

I know having those additional external oil ines have been known to leak

None of my earlier YZF oil lines ever leaked.

[Indetrucks]

None of my earlier YZF oil lines ever leaked.

Lucky you.. My roomates 05 YZ250F did

[grayracer513]

Lucky you.. My roomates 05 YZ250F did

It's not luck. I never disturbed them except for once when I first got the bike to check the condition of the feed screen. If you monkey with them all the time, or use the feed line to drain the oil, you will of course increase the chances of creating a leak, but if you install them right and leave them alone, there's no real reason for them to leak at all.

[Indetrucks]

It's not luck. I never disturbed them except for once when I first got the bike to check the condition of the feed screen. If you monkey with them all the time, or use the feed line to drain the oil, you will of course increase the chances of creating a leak, but if you install them right and leave them alone, there's no real reason for them to leak at all.

ok.. congratulations then ?