08 rebuild how far??

[gdbarr1976]

Hears my problem. I bought my 08yz450f in Feb of 08. Since then I have raced all the gncc's in 08, several this year, most sera hs, and a bunch of other local mx and enduros plus a 24hr race. Well over 100hrs.In Nov I am doing the Baja 1000 so it is now time for a rebuild. Up to this point I have adjusted the valves once. I know I will need a top end, valves piston etc.Parts cost $500. This is my issue. I am going to guess that when I pull it apart the cylinder will look pretty good and the bottom end will feel ok to. But, considering the hours and the upcoming Baja should I spend another $500 and replace the bottom end, main bearings and cylinder just to cover my bases? I think I know the answer but I guess I am looking for a little push.

[wondermuscle]

Have you raced Baja before? What class are you racing?

This year is going to be a loop again and from talking to Sal at the 500 the race is going to head down to Gonzaga bay and back up through some of the 2007 Baja 1000 course.

With all the money that you spend racing the 1000 I would recommend splitting the cases, put in new mains and go through the transmission and install WR gears. Enough can go wrong in the 1000, you should try and eliminate bike failure at all cost. It would be terrible to get halfway through the race and have a dog (sp) break off your 5th or 4th gear like yammy transmissions seam to do.

I ride and Race SCORE also and have an 08 YZ450. I run 14/46 gearing and it is not tall enough. You will want the WR trans.

PM me if you need maps or other info from past races.

[grayracer513]

The WR gear set would be a great mod for this king of racing.

But I have a question: How are your parts costing $500 including valves when there are 5 valves at $70~90 apiece? Hook me up with some of that.

If the bike just barely needed the next shim size, and the adjustment has stayed put since then, it's probably OK, but the only way to know for certain is top replace them.

Likewise, the crank has probably got a lot of time left on it, but if you went new, you'd know.

[gdbarr1976]

Have you raced Baja before? What class are you racing?

This year is going to be a loop again and from talking to Sal at the 500 the race is going to head down to Gonzaga bay and back up through some of the 2007 Baja 1000 course.

With all the money that you spend racing the 1000 I would recommend splitting the cases, put in new mains and go through the transmission and install WR gears. Enough can go wrong in the 1000, you should try and eliminate bike failure at all cost. It would be terrible to get halfway through the race and have a dog (sp) break off your 5th or 4th gear like yammy transmissions seam to do.

I ride and Race SCORE also and have an 08 YZ450. I run 14/46 gearing and it is not tall enough. You will want the WR trans.

PM me if you need maps or other info from past races.

I did the 500 solo in 07. Just ran the sportsmans class. I am going to solo this year but will start in the class 50.

I ran 15/48 gearing on a 06yz450 and was pretty happy with it. I will probably stick with that. I think you are right about spliting the cases but was just looking for some second opinions to make me feel a little better about spending the money. I am a total Baja noob but at 51 I want to mark it off my bucket list. Thanks for the input!

[gdbarr1976]

The WR gear set would be a great mod for this king of racing.

But I have a question: How are your parts costing $500 including valves when there are 5 valves at $70~90 apiece? Hook me up with some of that.

If the bike just barely needed the next shim size, and the adjustment has stayed put since then, it's probably OK, but the only way to know for certain is top replace them. Valves $57 apiece.

Likewise, the crank has probably got a lot of time left on it, but if you went new, you'd know.

I got these prices this morning off www.yamahapartsnation.com They advertise 40% off. They did seem cheap to me too. Check it out and see if I am missing anything.

I really don't want to turn my yz into a wr. With 15/48 gearing it goes as fast as I want to go on a motorcyle! Thanks for the input.

[642MX]

If it was my bike.... I'd replace the lower end along with the top end. At Baja, failure is not an option.

[davcon]

Interesting post. For me at 50 yo I'd be more concerned about the ol bod! How many hours is the 500? I average about 25 mph on a two track so this would be a 20 hr race for me? I'd probably just run it as is since I race about the same pace as I ride. ie try to use the clutch on every shift, keep the revs down by short shifting, dont ring it out etc. How hard have you been on the machine to this point? Thats what i'd consider. Love to see pics of your prepped bike. Lights, dez tank, gps, skid plate. I assume its all there. Kudos for running a YZ. Cant imagine a better bike for the job

[wondermuscle]

Cant imagine a better bike for the job

How about a WR 450... ?